Index

aacetamide function photochemistry 154acetone, a-cleavage 54acetophenone derivatives 146, 149, 189N-acetyl-2,5-dimethylpyrrole 388acetylfurans, oxetane formation 224acid-catalysis in photoreactions 148acrylanilides reactions 300acyclic alkenes 174acyclic dienes 364acyclic ketones 247– d-hydrogen abstraction 247acyclic N-allyliminium salt 269acyclic polyenes 267acyclic vinyl ethers, addition to carbonyls 230acyl oxyl radical 1582-acylpyrroles 390acylsilanes, oxetane formation 232adamantylideneadamantane-1,2-

dioxetane 355adamantyl-substituted alkenes 355, 356alanine 252, 254– photocyclizations 254aldehydes, oxetane formation 224alicyclic divinyl-methanes

rearrangement 102alkenes 68, 111, 191, 219– alkoxy-substituted 356, 357– alkylated 327– asymmetric epoxidation 124– benzene addition to 147– carbenes addition of 111– cycloaddition reaction 219– electron acceptor substituted 69–76– electron donor substituted 198– electrophilic, radical addition to 69–76– hydration 80– hydroalkoxylation 80

– intramolecular [2þ1] reaction withcarbenes 111

– intramolecular [2þ2] reaction 146, 219– metal-catalyzed cyclopropanation-supported

photochemistry 112– nucleophilicities 222– oxetane formation 221– photocycloadditions 144, 171– triplet sensitizers for 111– X–Y addition 83–86alkenols 196alkenyldiazo ketones 113– intramolecular cyclopropanation 1134-alkenyloxy-2-pyrones 203a-(alkenyloxy)silyl-substituted

diazoacetate 111– direct photolysis 111O-alkenyl salicylic acid derivatives,

transformation 149N-alk-4-enyl-substituted maleimides 309b-alkoxycarbonyl compound 2483-alkoxycarbonyl-substituted

cyclohexenones 178– trans-products formation 178b-alkoxy ketones 247, 2502-alkoxyoxetanes 222, 223o-alkoxy phenyl ketones,

photocyclization 2504-alkoxypyridones 1924-alkoxyquinolones 204allenes 190, 204– intramolecular [2þ2]

photocycloaddition 190(�)-allocoronamic acid synthesis 31(�)-allocyathin B3 synthesis 182N-allyl-N-(2-chlorophenyl)-acetamide 343allyl ethyl ether 196allylic alcohols 196, 231

j449

Handbook of Synthetic Photochemistry. Edited by Angelo Albini and Maurizio FagnoniCopyright � 2010 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimISBN: 978-3-527-32391-3

– bicyclic alcohol 273– oxetane formation 231allylic hydroperoxides synthesis 368–370– from simple alkenes 368–370– in zeolites 370allylic silanes 223, 327allyliminium salts, photochemistry 2694-allyloxycoumarin 203alternative energy sources, importance 10amines addition 72–74aminoacids (bis) synthesis 48o-tert-amylbenzophenone 244angular tricyclic cyclobutene derivative 148anilides photocyclization 299, 300anthracene endoperoxide 362aplysiatoxin, synthesis 419aquariolide A, synthesis 103, 104arc– antimony-xenon 9– mercury 3–8– mercury-xenon 9– sodium 9– xenon 9archimedene C120, partial structure 157arenes– intermolecular [3þ2] cycloaddition with

alkenes 119– intramolecular [3þ2] cycloaddition with

alkenes 119–122– oxygenation 359–363aromatic compounds

photocycloaddition 144–150, 311aromatic ketones 291, 324– as electron acceptors 291, 292– in SRN1 reactions 324aromatic nucleophilic substitution,

mechanisms 319ArSN1 reaction 319–345ArSRN1 reaction 319–345aryl amide anions 329–331, 342– intramolecular ortho-arylation 342aryl amine photoreaction 262arylation process 319–345aryl-carbon bond formation 319–345aryl cations 319–345arylglyoxylates 228, 229– oxetane formation 228aryl halides photoreaction 319–345aryl phosphates photoreaction 336, 337a-arylpropionic acids synthesis 325aryl radical cations 277aryl sulfonates photoreaction 336, 337, 345asteltoxin synthesis 228asymmetric hydroperoxidation 370

asymmetric ring-expanding allylation 187asymmetric synthesis, of oxetanes 231aubergenone synthesis 39avenaciolide synthesis 2284-aza-2-cycloalkenones photoreaction 183aza-di-p-methane rearrangement 99, 105,

109, 110– of b,g-unsaturated imines 109, 110azavinylcyclopropane photochemical

rearrangement 261azepines synthesis 406, 407azepinoindole derivatives synthesis 2932-azidopyridines photoinduced ring-

enlargement 407aziridine 124, 254, 258– conversion to L-daunosamine glycoside 124– photolysis 258– ring opening to azomethine ylides 258, 278– synthesis 123–125azo compounds preparation 33– aliphatic, nitrogen elimination 33, 34– Diels–Alder reaction 33, 34– hydrogenation 33, 34azoles reaction 78azomethine ylides 258, 279

bBarton esters, photolysis 85Beer�s law, negative implications 12belactosin A precursors synthesis 48, 49benzaldehyde Paternò Büchi reaction 226,

227benzannulated perhydroazulenes

synthesis 256benzene 144, 145– derivatives oxygenation 359–361– intermolecular [2þ2]

photocycloaddition 145benzocyclobutene derivative synthesis 147benzofuranols synthesis 250benzofurans synthesis 279benzoin derivatives photolysis 428–429benzoindolizidines synthesis 270benzophenone– as sensitizer 189, 196– in Paternò-Büchi reaction 221, 233benzoxazolin-2-ones synthesis 399N-benzoylenamines photoreaction 2991-benzoyl-1-(o-ethylphenyl) cyclopropane

photocyclization 246N-(b-benzoylethyl)-N-tosyl-glycinamides

photolysis 2505-benzoyl-4-methylbicyclo[2.2.2]oct-5-en-2-

one, preparation 108, 109

450j Index

– by Diels–Alder reaction 108benzvalene-like intermediates 393benzyl alcohol derivatives as protecting

groups 421, 422N-benzyl b-aziridinylacrylonitrile

photoreaction 2588-benzyl-1-benzoylnaphthalene

photoreaction 247N-benzyloxycarbonyl group, photolytic

removal 421a-(o-benzylphenyl)methyl phenyl ketone

photoreaction 246benzyl(trimethyl)silane radical

precursor 71benzyne 28bicyclic cyclobutanes synthesis 311bicyclic 1,3-cyclohexandione derivatives

synthesis 147bicyclic b-lactame synthesis 158bicyclic oxetanes 224, 228, 229– exo-selective formation 229– stereoselective formation 229bicyclic oxocarbenium ions 277bicyclic sulfone synthesis 159bicycloheptane derivatives synthesis 187bicyclo[3.2.0]heptan-3-one 36– photodecarbonylation 36bicyclo[2.2.1]hept-5-en-2-one 107– direct photolysis 107– oxadi-p-methane rearrangement 107, 108bicyclo[n.1.0]alkyl synthesis 117, 118bicyclo[2.2.2]oct-5,7-dien-2-ones 106– oxadi-p-methane/di-p-methane

rearrangements 106, 107bicyclo[2.2.2]oct-5-en-2-ones oxadi-p-methane

rearrangement 110[1,10] binaphthalenyl-2,20-diol (BINOL)

derivatives synthesis 330biphenyl as cosensitizer 267, 268biradicals 242–246, 248, 250, 252, 254, 260,

288, 289, 291, 307, 308– 1,4-acyl-alkyl 36, 37– 4,4-(1,n-alkanediyl)bisbenzyl 308– by photoelimination 25, 36–38, 40, 60– 1,5 cyclization 242, 246– cycloelimination reaction 36– decarbonylation 36– 1,n intermediates 291– intermediates in oxetane formation

220–223, 226, 227, 230, 233– stability rule 221– transition state model 246bisallyloxynaphthalene photoreaction 79bis(amino acids) preparation 47, 48

2,3-bis(p-methoxy phenyl) oxiranesphotoreaction 255

bisperoxides synthesis 371–373– from cyclic alkenes 372, 373– from phenyl-substituted alkenes 371, 372bistannylated aromatic compounds

synthesis 332biyouyanagin A synthesis 184black light lamp, see Wood�s lampbridged dihalosulfide formation 40– with 1,5-cyclooctadiene 40bromoaryl alkyl-linked oxazolines

photoreaction 339butenolides photoreaction 189, 190, 365N-tert-butoxycarbonyl(Boc)-protected lactams

photoreaction 192tert-butyl ketone photoreaction 36g -butyrolactones photodecarboxylation 39, 40buxapentalactone synthesis 122

ccage effect 43, 44, 60– nonstereospecific 44– stereospecific 44calicheamycin, synthesis 419carbanions in SRN1 reactions 323–326carbazoles, from diphenylamines 262carbenes 111– in the synthesis of three membered

rings 111–114– intermediates 32, 36carbocycles synthesis 270, 338–341– via ArSRN1 reaction 338–341carbohydrate furans 123– dye-sensitized photooxygenation 123carbon – carbon bond formation 25, 27, 28,

30, 33, 42, 44, 172, 187, 266, 323–331– by photoelimination of small molecules 25– fragmentation 258– generality 28– in crystals 25– unstable molecules synthesis 27–29– via carbanions 323–326– via radical addition onto C–C multiple

bonds 67– with cyanide ions 331– with nucleophiles 326–329carbon–carbon double bonds, addition to

69–86– H–C addition 69–76– H–N addition 76–78– H–O addition 80–82– H–P addition 78–80– H–S addition 82, 83

Index j451

– X–Y reagents to alkenes 83–86– halogenation 84– with C–C bonds formation 84–86carbon–carbon triple bonds, addition to

86–88– hydroalkylation reactions 87– X–Y reagents addition 87carbon-heteroatom bond formation 332–334– via sulfur nucleophiles 333, 334– via tin nucleophiles 332, 333carbon nanotubes– oxygenation 362, 363– single-walled (SWCNTs) 363carbonyl compounds– electron-accepting 219– electron transfer reaction 223– reaction with alkenes 217–233– reactions via the singlet state 220, 221– reactions via the triplet state 243, 247, 250,

252, 254carbonyl ylides 254–257, 279carcerands in photochemistry 28(�)-carnosadine synthesis 31a-cedrene synthesis 141C-furanosides synthesis 274charge-stabilizing solvent 328charge transfer (CT) complex 321chemically initiated electron exchage

luminescence (CIEEL) 358chemoselectivity, in oxetane formation 224chiral auxiliary approach 108chiral N-(2-benzoylethyl)-N-tosylglycinamide

reaction 251chiral cyclobutane synthesis 188chiral hexadiine derivatives

photoreaction 150chiral induction, in the synthesis of

oxetanes 232chiral N-tosyl glycine esters reaction 252chloroacetamides, electron acceptors 292,

2934-chloroaniline photoreaction 329cholesterol-ketoprofen dyads, irradiation 307chromatic orthogonality 424, 428, 430–431chromium cyclopropanone intermediate

formation 156chromophoric dissolved organic matter,

photosensitizer 355cinnamylanilides photocyclization 311cinnamyl esters 425, 426– Z/E photoisomerization 425, 426circularly polarized light 175cisoid conformations 364– (E,Z)/(Z,Z)-2,4-hexadienes 364

a-cleavage reaction 25, 26, 36, 40, 50, 52, 54,59, 106

colchicine synthesis 152(�)-complicatic acid synthesis 110concerted elimination 30conjugated dienes oxygenations 364–367– acyclic dienes 364– cyclohexadienes 364, 365– cyclohexatriene 365–367– cyclopentadienes 364, 365– heterocycles 365–367copper-catalyzed [2þ2]

photocycloadditions 139cosensitizer, 1,3,5-triphenylbenzene 77coumarins 193, 194– [2þ2]-photocycloadditions 194critical micelle concentration 59crown ethers, synthesis 288crystalline solids 25, 26crystalline suspension, photoreactions 25, 59crystal-phase photochemical reactions 15CuOTf-catalyzed [2þ2]

photocycloaddition 141–144– inter/intramolecular 144– norbornene derivates 143(R)/(S)-a-cuparenone 57– enantioselective synthesis 57, 581-cyanonaphthalene– derivative photoreaction 146– sesnsitizer 2761-cyano-2-(4-pentenyl)naphthalene derivatives

photoreaction 1219-cyanophenanthrene as photocatalyst 75a-cyanostilbene oxides photoreactions 2552-cyano-substituted pyrroles synthesis 3893-cyano-1-thiocoumarin photoreaction 198cyclic alkene reaction 174, 175, 226cyclic 1,3-diketones photoreaction 186cyclic ketones 56– ring-contraction product 56– cis/trans-a,a0-substituents 56cyclic oligopeptides synthesis 288cyclic sulfones 41– photo-elimination products 41, 42cyclic tertiary amines addition 73cyclic triene chromium complexes

cycloaddition 306cyclization, in five-membereed ring

formation 242, 245, 250–252, 264, 265,267, 270, 272, 276

– electron transfer 267– radical 268, 274– radical anion 272– selectivity 246

452j Index

– stilbene-like 295–298– vinyl-biphenyls 299cycloaddition reactions– [2þ1] 111– [2þ2] 35, 137–160, 171–173, 264–311– carbonyls with alkenes 217,219,223– copper catalyzed 139–144– in the synthesis of four memberedrings 137–160– intramolecular 138– of aromatic compounds 144–150– of 4-aza-2-cyclohexenones 185– of coumarins 193, 194– of cyclohexenones 177–181– of cyclopentenones 173–177– of 1,3-dioxin-4-ones 198–200– of dioxopyrrolines 184– of enones 173–181– of Fischer-type carbene complexes 156– of 4-heterocycloalkenones 183–185– of 2�,3�-O-isopropylideneuridine 201– of maleic anhydride and derivatives 196,197– of 4-pyrimidinones 200, 201– of quinolones 194, 195– of p-quinones 181, 182– of 1-thiocoumarin 198– a,b-unsaturated carbonyls 172– of a,b-unsaturated carboxylic acidderivatives 189–201– of a,b-unsaturated lactams 192, 203–205– ofa,b-unsaturated lactones 189–192, 202,203– of vinylogous amides and esters 182

– [2þ2þ2] 156– [3þ2] 119, 254–258, 279, 311– for the synthesis of natural products 122– of arenes with alkenes 119–122, 144

– [4þ2] 144, 300– photoenolization/Diels Alderreaction 301– rules 255, 258– singlet oxygen as dienophile 364– transition metal template controlled304–306, 309

– [4þ4] 138, 302–305– [5þ2] 310– [6þ2] 305– [6þ4] 305– 1,3-dipolar 265, 278– five-membered rings formation 254– four-membered rings formation 101– large rings formation 302–305– meta 119, 144

– para 144– with singlet oxygen 353, 357, 358, 364, 373,

374, 376cycloalkenones photoreactions 182cycloalkyl peroxides, UV irradiation 46cyclobutane synthesis 33, 137–160,

171–205– by elimination 33– from lactones 180cyclobutanol derivatives 36, 154, 155, 159– photodecarbonylation 36– synthesis of, via Yang cyclization 153–155cyclobutene synthesis 137, 189g -cyclodextrin effect on cycloadditions 120,

181cycloheptatriene derivative 367– TPP-sensitized photooxidation 367cyclohexadienes 364, 365, 372– TPP-sensitized photooxidation 3721,5-cyclohexadien-3-one, rearrangement 104cyclohexatriene oxygenation 365–367cyclohexenones, [2þ2] cycloaddition of

177–180– 4-hetero-2-cyclohexenones, [2þ2]

cycloaddition of 185–186N-cyclohexylmaleimide cycloaddition 197cyclopentadecanone synthesis 47cyclopentadienes oxygenation 364, 365cyclopentanol ring system, formation

242–247, 273– benzofuranols 250– indanols, synthesis 243–247– pyrrolidine derivatives, synthesis 250–254– tetrahydrofuranols, synthesis 247–254cyclopentanones 52– a-cleavage 52– enamine of 263cyclopentene reaction 178, 195– endo-products 174– exo-products, formation 174– from vinylcyclopropanes 261cyclopentenone, [2þ2] cycloaddition

173–177– 4-hetero-2-cyclopentenones

cycloaddition 183–185cyclophanes synthesis 28, 29, 40– double cyclization reactions 28– precursors 28– synthesis 29cyclopropane formation 31, 37, 114, 115, 254– by elimination 31– by intramolecular hydrogen

abstraction 114–118– by intramolecular PET 115–117

Index j453

– b-morpholinopropiophenonesirradiation 115

– transition metal-mediated carbenetransfer 95

cyclopropylamines, photoreactions 271cyclopropylaminoacids synthesis 31, 32, 47,

48cyclopropyl ketones, electron transfer

photoreactions 275cyclopropyl silyl ethers, photoreactions 268cylindrical cuvettes, see spectrophotometric

cuvettescynnamyl esters, Z/E isomerization 425, 426a,b-cyperone synthesis 39

ddecarbonylation, of ketones 25, 28, 30, 35, 36,

50, 54, 309decarboxylation 28–30, 39, 46, 47, 288, 289,

303, 309de Mayo reaction 85, 182, 187demecolcine, synthesis of 152denitrogenation from azo compounds 28,

31–339,10-deoxytridachione,

photorearrangement 103diacyl peroxides 44, 46, 47– decarboxylation products 46, 47, 48– photolysis reaction 45trans-dialkenyl cyclohexanone, irradiation 551,2-trans-dialkylated cyclopentanes

synthesis 272N,N-diallyl-(2-chlorophenyl)-amine

cyclization 343diarylethenes, photochromic

compounds 298diazepines synthesis 407–409diazoalkane, in situ generation 31, 32a-diazo carbonyl compounds 111, 112– intramolecular [2þ1] cycloaddition 112diazoketone photoreaction 392dibenzofurans synthesis 262dibenzothiophenes synthesis 262N,N-dibenzyl-2-benzoylacetamide

photolysis 2511,5-dichloro-9,10-anthraquinone 81– photoacid generator 811,4-dichloro-2-butene cycloaddition 1969,10-dicyanoanthracene as sensitizer 2561,4-dicyanobenzene as sensitizer 77, 267, 3011,1-dicyano-3,3-dimethyl-1,4,5-hexatriene

direct photolysis 1011,4-dicyanonaphthalene as sensitizer 139,

270

3,3-dicyanostilbene oxide cycloaddition 2551,4-dicyano-2,3,5,6-tetramethyl benzene as

sensitizer 267Diels–Alder reaction, see [4þ2] cycloaddition6,6-diethoxyfulvene 372– sensitized photooxygenation 372difluoromethyl radicals 74dihalobenzenes in SRN1 reaction 324dihydrobenzofuranes synthesis 3449,10-dihydrophenanthrenes synthesis 299dihydropyridinone photoreactions 185, 233– 2,3-dihydropyridin-4(1H)-ones 185– 5,6-dihydro-1H-pyridin-2-ones 2041,5-dihydropyrrol-2-ones photoreaction 204dihydrosantonin 39– direct photodecarboxylation 391,8-diiodonaphthalene 338, 346– photostimulated reaction 3461,5-diketone derivatives synthesis 1831,3-diketones photoaddition 851,4-dimethoxynapthalene as sensitizer 272dimethyl acetylendicarboxylate

cycloaddition 2564-(N,N-dimethylamino)benzonitrile

synthesis 331N,N -dimethylaminophenyl cation 3291,16-dimethyl-dodecahedrane synthesis 2432,5-dimethyl-furan 365– TPP-sensitized photooxygenation 3652,5-dimethyl-2,4-hexadiene arylation 3281,4-dimethylnaphthalene-1,4-endoperoxide

synthesis 361dimethyloxosulfonium methylide 217g -dimethylvalerophenones

photoreaction 243a,o-diolefins photoreaction 203dioxapaddlanes see endoperoxidesdioxetanes 354–358– adamantyl-substituted alkenes 355, 356– alkoxy-substituted alkenes 356, 357– phenyl/methyl-substituted alkenes 357,

3581,3-dioxin-4-ones 198–200– de Mayo-type photochemistry 1991,3-dioxol derivatives Paternò-Büchi

reaction 229diphenyl amine, photoreaction 2622,2-diphenyl-3,3-dimethyloxetane

synthesis 221cis/trans-diphenylindanones

photoreaction 50, 51di-p-methane rearrangement 96–104– acetone-sensitized 97– of acyclic systems 100–103

454j Index

– of barrelene 96, 99, see also Zimmermanrearrangement

– of benzobarrelene, acetophenone-sensitizedirradiation 96, 97

– of dibenzobarrelene 96, 97– direct irradiation 97, 98– in natural compounds 103– in the solid state 98dipolarophiles 254–256, 258, 278, 279disproportionation of biradicals 242, 244N,N-disubstituted amides, carbanions in SRN1

reaction 3254,5-disubstituted N-alkylimidazoles

synthesis 3963,4-disubstituted-1,2,4-thiadiazolin-5-ones

synthesis 4052,5-disubstituted-thiophenes 393– photochemical synthesis 3932,4-di-tert-butylacetophenone

photoreaction 2431,3-divinyl-2-cyclopentanol tetronates

photoreaction 202

e(�)-elacanacin, synthesis 181electrocyclic reactions 150, 261–263, 295– cyclobutadiene 287, 295, 299– cyclobutene ring opening 310– in crystals 150– with tropolone derivatives 150electron paramagnetic resonance (EPR) 28electron-rich olefins photoreactions 82, 194,

356electron transfer ring opening– cyclopropanes 260– epoxides 261, 267–270, 272, 273, 276, 277,

279electron-transfer photooxygenation 364electron-transfer sensitizer 293–295, 357– dicyanoanthracene (DCA) 293, 311– dicyanonaphthalene (DCN) 293, 311– 9-mesityl-10-methylacridinium ion 357enamides photocyclization 299, 300endoperoxides, synthesis of 358–368– by electron-transfer photooxidation 364– from arenes 359–363– from conjugated dienes 364–367ene reactions, (with singlet oxygen) 353,

357–359, 368–370, 372, 374enol silyl ethers as electron donors 294enolate anion 265, 323– in ArSRN1 reaction 323–325, 329, 341–344,

346enones

– photoalkylation 71, 75, 80– photocycloaddition 173–182epimaalienone synthesis 391,4-epiperoxides, see endoperoxidesepoxides 123, 217– ring-expansion reaction 217– synthesis 123a,b-epoxyketone photoreaction 256(�)-erysotrine, synthesis of the precursor

185erythrolides B synthesis 104esters, decarboxylation 283-ethoxycarbonylcoumarin

photoreaction 193b-ethoxypropiophenone photoreaction 243,

247ethyl a-(o-benzoylphenoxy)carboxylates 250– photocyclization 250a-(o-ethylphenyl) acetophenone

photoreaction 245ethyl propiolate, radical addition to 88ethyl vinyl ether– addition 86– cycloaddition 257eupoulauramine, synthesis 343external irradiation set-up 6

ffacial diastereoselectivity 190falling film photoreactors 13farnesol, photoreaction 267Fischer-type carbene complexes 156– photochemical [2þ2]

photocycloaddition 156Fischer-type chromium carbene

complexes 158– photochemical transformations 158five-membered ring, formation 241, 387– azomethine ylides generation 258–260– [3þ2]-cycloadditions formation 254– from vinyl cyclopropanes 260–261– internal cyclization-isomerization route

(ICI) 387– oxiranes, photofragmentation 254–257– ring contraction-ring expansion route

(RCRE) 387, 398– photochemical rearrangement 260–261– with one heteroatom synthesis 388–393– with three heteroatoms synthesis 402–405– with two heteroatoms synthesis 393–402fluorescent lamps 6fluorobiprophen, synthesis 323four-membered ring systems 157, 159– synthesis 137–160, 171–205

Index j455

fragmentation/elimination in synthesis 2627 29 36

3(2H)-furanones reactions 184furans– photoreactions 224–227, 261, 337– synthesis 3912-furylmethanol photoreaction 230

ggeraniol photoreaction 267(�)-ginkgolide B synthesis 177glycosyl radicals 88(�)-grandisol, synthesis 140, 141Griesbeck model for oxetane formation 226(�)-guanacastapene synthesis 177

hhaloarenes– photocyclization 293– SN1 reactions 319– SRN1 reactions 319halogenation reaction 84Hammond postulate 26(�)-heliannuol D synthesis 185hemiketal hydroperoxide synthesis 374herbertene synthesis 141, 142heterobicyclo[4.1.0]alkyl ketones

synthesis 117, 118heterocycles– oxygenation 365–367– synthesis 387–410(E,E)-2,4-hexadiene oxygenation 364hexamethylbenzene-1,4-endoperoxide

synthesis 359hexatriene cyclization 298high-pressure mercury lamp 4, 173high-pressure xenon arcs 9(�)-hirsutene, synthesis 110, 111, 273(þ)-hirsutic acid, synthesis 110home-made continuous flow microreactors,

advantages 14homobenzoquinones photoreaction 182homobenzylic ether radical cations 276hydroacylation reactions 75, 76hydroalkylation reactions of alkenes and

alkynes 69–76, 87– hydrocarboxylation reactions 75, 76– hydrofluoromethylation 74– via alcohols addition 71, 72– via alkanes addition 70, 71– via amines addition 72–74– via ethers addition 71, 72– via nitriles addition 75hydroacylation of olefins 75, 76

hydroamination of olefins 76–78hydroarylation of olefins 76hydrocarboxylation of olefins 75, 76hydrofluoromethylation of olefins 74hydrogen abstraction– from unactivated substrates 70–72, 75– in b 115– in the synthesis of cyclopropanols 115

– in g 117, 118, 241, 243–245, 247–250, 253– in the formation of three memberedrings 117, 118– in the formation of four memberedrings 153–156

– in d 153–156, 181, 242, 245– remote 287, 307, 309

hydrogen bonding in enantioselectivesynthesis 196, 233

a-hydroxy(alkoxy)alkyl radicals 71a-(1-hydroxyalkyl)-substituted a,b-unsaturated

ketones 116– direct photolysis 1164-hydroxycoumarin photocycloaddition 2034-hydroxy-2-nonenal photorelease 4233-hydroxyproline esters synthesis 2524-hydroxyquinolones photocycloaddition 204hypoglycin A synthesis 48

iimidazoles synthesis 394–398imidazoline reaction 156iminium salts, photochemistry 269immersion well irradiation apparatus 7(�)-incarvilline synthesis 176indanols synthesis 243–245– E-indanol 246indoles, from enamines 263indolines 263, 429, 430– as photoremovable protecting group 429,

430– from electron transfer cyclization 277– from enamines 263– cis-indoline 263– stereochemistry 263indolylketones, from enaminones 264(�)-ingenol, synthesis of 199, 200inner filter effect 13intense light sources, effect 17intermolecular cyclopentenone [2þ2]-

photocycloaddition 175– facial diastereoselectivity 175intermolecular dipolar cycloadditions 31, 33intermolecular hydrogen bonding 177intersystem crossing (ISC) 153, 171, 220, 323intramolecular [2þ1] cycloaddition 111

456j Index

intramolecular [2þ2] cycloaddition 101, 311– regioselectivity 176intramolecular hydrogen abstraction

114–117, 153, 247, 2872-iodobenzenesulfonamide

photoreaction 3461-iodonaphthalene photoreaction 3254-iodo-1,1,2,2,9,9,10,10-octafluoro[2.2]

paracyclophane photoreaction 334ionic liquid as the reaction medium 144irradiation apparatus 2–11– amateur version 5– light sources 9– low-pressure mercury arcs lamps 3–6– medium/high-pressure mercury arcs

lamps 7, 8isoleucine derivative, Yang cyclization 154(�)-iso-retronecanol synthesis 73, 270isothiochroman derivatives synthesis 302isoxazole-to-oxazole rearrangement 399, 401isoxazolin-5-ones 397, 400– photochemical reactivity 397

k(�)-kainic acid synthesis 192kalasinamide, reaction with singlet

oxygen 368(�)-kelsoene synthesis 175ketene silyl acetals, arylation 329ketones 35, 38, 52, 56, 57, 105, 117, 273– alkenyl, cyclization 274– a-cleavage 25, 28, 30, 35, 36, 50, 52, 54– decarbonylation 25, 26, 36, 40, 52, 54, 59– enantiospecific 56– in the solid 51

– photodecarbonylation 35, 51, 57– photoinduced electron-transfer 273ketoprofen-tetrahydrofuran dyad

photoreaction 307ketyl radicals, generation 274

l(þ)-laburnine synthesis 73b-lactams 155– formation 41– Yang cyclization 155g -lactols synthesis 72lactones decarboxylation 39ladderane synthesis 33–35– from diazenes 33lamps 3, 4, 5– black light 6– coiled 5– doped 8

– for external irradiation 5– Hg-lamps 8– low-pressure mercury arcs 3–6– mercury resonance 3– phosphor coated 6– photochemical syntheses with 4– quartz 6– reaction vessel system 3– tungsten 9– tungsten-halogen 9– U-shaped 5– Wood�s 6lancifodilactone F synthesis 122lasers light 9– XeCl excimer laser 9leaving groups in photochemistry 117, 417LEDs see light-emitting diodesligand to metal charge transfer 139light-emitting diodes (LEDs) 9, 10, 15, 18linalyl acetate photorelease 423(�)-linderol A synthesis 193(þ)-lineatin synthesis 189,190longifolene synthesis 31low-pressure lamp 6– advantages 6– electrodeless 6– Hg arcs lamps 3–6, 15low-temperature experiments 8low-temperature matrices 28lumicolcine synthesis 152lumicolechecine derivatives synthesis 152lumi/lumiketone rearrangement 104lumisantonin synthesis 104Lycopodium alkaloid synthesis 110, 111

mmacrocyclic synthesis 288, 293, 307–310(�)-magellanine synthesis 110, 111malononitrile 75– anti-Markovnikov photochemical

addition 75marcanine A synthesis 368mazdasantonin synthesis 104medium-pressure mercury lamp 14– immersion well 14(�)-meloscine synthesis 195(�)-merrilactone A synthesis 175, 190, 232metal-catalyzed formation of four membered

rings 156, 157metal complexes effect onphotoreactivity 304methanoglucamic acid synthesis 31methoxy carbazoles preparation 3413-methoxycarbonylcoumarin

photoreaction 193

Index j457

4-methoxypyridone photoaddition 2044-methoxyquinolone photoaddition 204d-methoxyvalerophenone photoreaction 242a-(N-methylanilino) styrene 263– photocyclization-rearrangement 2633-methyl-1-butene cycloaddition 193methyl 1,3-dihydroisoindole-2-carboxylate

reaction 119– with cyclopentene 119, 1202-methyl-furan 225– Paternò Büchi reaction 2253-methylisoxazolo[5,4-b]pyridine,

reaction 125, 126N-methylquinolinium hexafluorophosphate as

sensitizer 276migration-nucleophilic attack-cyclization 403multilamp apparatus 4, 6– rotating merry-go-round 6

nnaphthaldehydes, Paternò Büchi

reaction 226naphthalene derivatives 146– endoperoxides 361, 362– [2þ2] photocycloaddition 146naphthobarrelene, direct irradiation 991,4-naphthoquinone photocycloaddition 1812-naphthoxide ions SRN1 reaction 330b-necrodol synthesis 141, 142neocarzinostatin synthesis 41o-nitrobenzyl alcohol derivatives 418–420nitrogen heterocycles synthesis by SRN1

reaction 341–344nitromethane anion in SRN1 reaction 343NOCAS reaction 84nonconjugated alkenes 137– [2þ2]-photocycloaddition 137–144Norrish reaction 153, 307, 418, 423– general mechanistic scheme 153– type I group 36, 159, 424– type II group 154, 418, 423, 427– Yang reaction, relation to 153NPEOC photolabile protecting group 419N2 photoelimination reaction 35NPPOC photolabile protecting group 419nucleophiles in SRN1/SN1 reaction 321,

326–329

oolefins see alkenesOppolzer�s chiral acryloyl sultam

reaction 258orthogonality of photoremovable protecting

groups 417

ozonides formation 3654-oxa-2-cyclohexenones photochemistry 1854-oxa-2-cyclopentenones cycloaddition 183oxadiazoles 402–404– ring contraction–ring expansion route

rearrangement 403– synthesis of 402–404oxa-di-p-methane rearrangement 105–111– in zeolites 107– of b,g-unsaturated ketones and

aldehydes 105–109– synthetic applications 110oxazepines synthesis 409–410oxazoles 398–400– photoinduced RCRE rearrangement 398– synthesis 398–400oxetanes synthesis 217–233, see also

Paternò–Büchi reaction– asymmetric 231– bicyclic 228, 229– chiral induction 232– diastereoselective formation 231– enantioselective synthesis 232– endo-selective formation 227– exo-selective formation 228, 232– formation 218– intramolecular cyclization reactions 218– O,S-ketene silyl ether 227– preparing methods 217– radical ion pairs 224– regioselective formation 221–226– cis-selective formation 227– site-selective syntheses 221–226– stereoselective formation 219, 221,

226–233– temperature effect 225, 226N-oxides photoreactions 390–392, 410oxiranes, fragmentation 254–257oxiranes, opening to carbonyl ylides 254oxygenations 353, 355, 364, 369, 374, 377

ppalladium-catalyzed reaction 335Paternò–Büchi reaction 219–233, see also

oxetane synthesis– benzoin derivatives 428– mechanism 220– regioselectivity 221–226– singlet state 220, 221– stereoselectivity 226–233– temperature effect on selectivity 225– triplet state 221pentacene-6,13-endoperoxide synthesis 363(þ)-pentacycloanammoxic acid synthesis 175

458j Index

(�)-pentalenene synthesis 178pentaprismane synthesis 138perfluoroalkylethylenes alkylation 72perfluoroalkylpyridazines photoreaction 406(�)-perhydrohistrionico toxin synthesis 188perhydroindolizines synthesis 270peristaltic pump 13phenacyl esters as photolabile groups 426,

427phenanthrene synthesis 2969-phenanthrol anion, SRN1 reaction 330phenanthroline synthesis 2992-phenylbenzimidazole, historical

synthesis 397[7]phenylene synthesis 157phenylglyoxylic acid esters Paternò Büchi

reaction 232phenyl/methyl-substituted alkenes 357, 358– diphenylindene photooxidation 357– electron-transfer photooxidation 357, 358b-phenyl quenching effect in decarbonylation

reaction 59phenylsulfanylcarbene, photosensitive

precursor 114phenyl vinyl sulfones alkylation 70(2-phosphinoethyl)silyl chelate ligand

synthesis 79phosphor-coated lamps 6, 18– advantages 6photocatalysis 3, 69–76photochemical C–C bond formation via

elimination– CO photoelimination from ketones in

solution 35–39– CO2 photoelimination from lactones 39– four-membered ring synthesis 33–35– N2 photoelimination reaction 31–35– polycyclic compounds synthesis 33–35– sulfur photoelimination from sulfides/

sulfoxides/sulfones 40– three-membered rings synthesis 31photochemical electrocyclic reactions

150–153, 261–266photochemical electron transfer, see

photoinduced electron transferphotochemical experimental methods 1–22– concentration and scale 11–15– experimental parameters 11–19– impurities effect 15– irradiation apparatus 2–11– oxygen effect 15– photochemical steps 19–22– safety 17– synthetic planning 17–22

– temperature effect 15photochemical synthesis– advantage 16– chemical efficiency 40– conditions for 2, 11– crystal phase 15, 27, 28, 43, 50, 53, 60– experimental parameters 11– features 19– flow microreactor 14– general schemes 20–22– large scale 13– low temperature 7– parameters 17– planning 17–19– practical hints 11, 15, 17– process intensification, miniaturization 14– safety precautions 17– solar light for 10– synthetic use, limitations to 13– temperature independence 16photochromic compounds 298photocycloadditions see cycloadditionphotodeoxytridachione synthesis 103photodimerization reactions 201photoelectron transfer-initiated

cyclizations 266–272, 287–295– aromatic ketones 291, 292– chloroacetamides 292, 293– electron-deficient aromatic

compounds 293–295– phthalimides as electron acceptors 287–

291– radical anion 272–276– radical cation 266–272– radical cations, intramolecular

trapping 276–279photoelimination reaction 26, 27, 30, 31, 44– advantages 27– concerted 30– disadvantages 27– enthalpic feasibility 26photoenolization/Diels–Alder reaction 302photo-Fries rearrangement 31photohydroalkylations 69photoinduced electron transfer (PET)

reaction 68, 78, 220, 256, 287–291, 293,294, 301, 315, 321

– carbonyl derivatives 220,221,223– in ArSRN1 reaction 320, 321, 324, 343– in the functionalization of olefin 68, 70,

73–75,78, 80– mediated cyclizations 266–279photolabile protecting group 417–432– benzoin derivatives 428–429

Index j459

– benzyl alcohol derivatives 421, 422– indolines 429, 430– o-nitrobenzyl alcohol derivatives 418–420– phenacyl derivatives 426, 427photo-NOCAS process 84photooxygenations 353, 355, 364, 369, 372,

377photoreactors 2– falling film 13– immersion well 7– miniaturized 14– multilamp 3– Rayonet 4photosensitizer 29, 37, 288,293,302, 311photostimulated SRN1 reactions 322phthalimides 287– cyclization 287–292– [5þ2] cycloaddition 310– electron acceptors 287–291– N-linked peptides photoreactions 291(S)-pipecoline synthesis 299piperidin-2,4-diones photoreactions 203pixyl group, photolability of 421polyaryls synthesis 334–338– alternative to metal catalysis 333–336– via photo-SN1 336 reaction 338polyenes– cyclization 267– electrocyclic reactions 150polynuclear aromatic compounds

synthesis 295– helicenes 295– phenacenes 295(þ)-premnalane synthesis 376N-prenylpyridinium perchlorates

photoreaction 270N-prenylquinolinium perchlorate

photoreaction 270(þ)-preussin synthesis 227process intensification through

miniaturization 144-propanoyl-6-methylpyrimidine, direct

irradiation 118prostratin synthesis 31protecting groups, photolability of 417–438prunolide C, synthesis of the core

structure 374(�)-pualownin synthesis 249(�)-punctaporonin C synthesis 202pyrazine photoreactions 396pyrazinobarrelene, acetone-sensitized

irradiation 99pyrazoles 393, 395– photorearrangements 395

– synthesis 393, 394pyrazolines, photodenitrogenation 31Pyrex vessel 188– filtered light 261, 297pyridinium salts, photoinduced

cyclization 124, 125pyridone derivatives 150, 192, 201, 303– electrocylization 150– photochemical electrocyclization 151– selective cycloadditions 3032,4-pyrimidindiones photoreaction 1984-pyrimidinones photoreaction 198, 200pyrroles 337, 388, 389– arylation 338– ICI rearrangements 389– synthesis 388–391pyrrolidine 258, 270– synthesis 251, 258, 278

qquadricyclene formation 34quartz lamps 6quinocarcin alkaloid synthesis 258quinoline-N-oxides, photoreactivity 390quinolizidine synthesis 185quinolones 194, 201– photocycloadditions 181– 2-quinolone photocycloaddition 194p-quinones, [2þ2] cycloaddition of 181, 182

rradical anion 272, 276, 294– scavengers 321radical cations 266, 267, 270, 272, 276, 277,

291radical pair 43, 44, 220– photoelimination 25, 27, 36, 40, 43,

44, 60radical-radical combination 25, 39, 44, 60radical scavengers 321– di-t-butylnitroxide (DTBN) 321– 2,2,6,6-tetramethyl-1-piperidinyloxy

(TEMPO) 321Rayonet reactor 4Rehm-Weller equation– and Paternò-Büchi reaction 220remote intramolecular hydrogen

abstraction 307–308re-precipitation method in solid state

photochemistry 59resorcinol derivatives reaction 147– benzocyclobutene derivatives

synthesis 147ring contraction 25–60, 308–311

460j Index

ring-expansion-ring-contractionprocesses 394

ring formation– five-membered 241–279– four-membered 137–160, 171–205,

217–233– large 288, 293, 307–310– six-membered 287–313– three-membered 31, 95–126rugulovasines A and B synthesis 340

ssafety in photochemical reactions 17salen complex catalyst 123a-santonin photolysis 104(�)-sceptrin synthesis 196selenophenes synthesis 261semibullvalenes synthesis 100sensitizers– electron-transfer 302, 303, 311– in oxygenations 353– triplet 29, 37, 288,293seven-membered heteroaromatic ring

synthesis 406–410silicon ethers as photoremovable hydroxyl

protecting group 424, 425b-silyl effect in cycloadditions 119silyl enol ethers 195, 222, 223– Paternò Büchi reaction 222a-silylmethylamine radical cations 270silyl phosphates in alkylations 80g -silylsubstituted cyclopentenone

cycloaddition 175single electron transfer (SET) see photoinduced

electron transfersinglet biradicals 221singlet oxygen chemistry 353–377– tandem reactions 371–377single-walled carbon nanotubes

(SWCNTs) 363Si–Si bond PET activation of 279sisyl group as photoremovable group 424six-membered heteroaromatic ring,

synthesis 406small-scale photoreactions 11– quartz/Pyrex tubes 11SN1 see Ar SN1 reactions(þ)-solanascone, synthesis 180solanoeclepin A synthesis 190solar light, photoreactions 10, 155, 362solid state, photochemical reactions 15, 27,

28, 43, 50, 53, 60– decarbonylation reaction 50–60– decarboxylation 44–50

– natural products synthesis 57– quenching effects 57– radical intermediates fate, restriction

of 43– radical stability and selectivity 53– reaction enantiospecificity 56– reaction scale/experimental conditions 59– reactivity/stability 42, 43, 51–53– scope of the reaction 55spiro compounds synthesis 268, 374–376spiro[2.2]pentanes synthesis 117, 118SRN1 see ArSRN1 reactionsSRN1–Stille sequence 335stereoisomeric tetrahydrofuran-3-ols

synthesis 248stereoselectivity in oxetane formation 226,

227, 230(�)-sterpurene synthesis 179cis-stilbenes 295– like photocyclization 295–298styrene 112– cis-selective/enantioselective

cyclopropanation 112styrylalkyl-N-substituted phthalimides 290– ring photocyclomerization 2905-substituted 3-H-azepin-2-ones

synthesis 4062-substituted furans synthesis 392N-substituted phthalimides reactions 2872-substituted thiophenes 393– photoisomerization 393(�)-sulcatine, synthesis 175sulfides, photoelimination 40sulfones, photoelimination 40sulfoxides photoelimination 40sulfur 40, 290– heterocycles 346– nucleophiles 333, 334– photochemical elimination 40, 411,4-sulfur–oxygen interactions 363sunlight mediated reactions see solar lightsynthesis, photochemical steps in 19

ttandem radical addition/cyclization

reactions 291tandem singlet oxygen reactions 371–377– in the synthesis of bisperoxides 371–372– rearrangement to hemiketal

hydroperoxide 374– rearrangement to spiro compounds

374–376tetrabutylammonium decatungstate,

photocatalyst 70–72, 75

Index j461

tetracyclic cyclopentaoxazoloisoquinolinonesystem synthesis 340

tetrahydrofuran derivatives synthesis 72,254, 255, 394

– via alkylation 72– via carbonyl ylides, cycloaddition of 254,

278– via electron transfer cyclization 276tetrahydrofuranols synthesis 247, 250(�)-tetrahylipstatin synthesis 72p-tetrahydronaphthoquinones 182– intermolecular [2þ2]-

photocycloaddition 182tetrahydrophthalic anhydride

photoreaction 1965, 10, 15, 20-tetrakis(heptafluoropropyl)

porphyrin sensitizer 3692, 20,4, 40-tetramethoxybenzophenone

sensitizer 112tetramic acids photochemistry 203tetra/penta/hexa-cyclic azonia-aromatic

compounds 297– oxidative photocyclization 2971,1,8,8-tetraphenyl-1-7-octadiene 301– intramolecular cycloaddition 301tetrazoamine, synthesis 125tetronates photochemistry 202tetronic acid amide 202– intramolecular photocycloaddition 202tetronic acid esters 202– photochemistry 2024-thia-2-cyclohexenones 186– [2þ2]-photocycloaddition reactions 186thiadiazoles synthesis 405thiazoles synthesis 400–402thiobenzofurans, from aryl vinyl sulfides 266thiocarbonyl derivatives b-hydrogen

abstraction 1251-thiocoumarin photocycloaddition 198thioketals as photoremovable carbonyl

protecting group 424thiophenes 261, 392– synthesis of 392, 393thiophen-2(5H)-one photoreaction 1974H-thiopyran-1,1-dioxide 102– direct/triplet-sensitized irradiation 102– di-p-methane rearrangement 102three-membered heterocycles photochemical

synthesis 123–126– aziridines 123–126– epoxides 123three-membered ring formation 95–126– by photochemical methods 95tin nucleophiles, in ArSRN1 reaction 332, 333

N-tosyl piperidine photoreaction 253transition metals template-controlled

reactions 304–306triarylpyrylium (TPP) salts sensitizers 302triazoles synthesis 404, 4051,2,4-triazolin-5-ones synthesis 404tricyclic cyclobutene derivative synthesis 149,

150tricyclic housane synthesis 33–35– from diazenes 33tricyclic ketone reactions 158tricyclic substrate 199– intramolecular [2þ2]-

photocycloaddition 199tricyclo[3.3.0.02,8]oct-3-ones synthesis 1064-trifluoromethyl substituted imidazole

synthesis 395trimethylsilylmethylamine radical cation 2701,3,5-triphenylbenzene synthesis 3341,1,3-triphenylpropane formation 50, 512,4,6-triphenylpyrylium terafluoroborate

sensitizer 279, 302triple [2þ2þ2] cycloaddition 157triplet carbenes generation 112– triplet sensitizer for 112triquinane (�)-pentalenene synthesis 178trithiabicyclo[2.2.2]octane (TTBO) derivatives

protecting groups 424trivinyl-methanes 102– direct/acetophenone-sensitized irradiation,

photoproducts 102– di-p-methane rearrangement 102tropolone derivatives 152– 4p electrocyclization 152, 153two-photon absorption crosssection 431–432

ub,g -unsaturated aldehydes 105– oxa-di-p-methane rearrangement 105–109a,b-unsaturated carbonyl compounds 171,

272– b-activation in cyclization reaction 272– addition to 80, 85– alkene E/Z isomerization 108– alkylation 80, 85, 291– function transformation 156– oxa-di-p-methane rearrangement 105–109– b-reductive activation 273a,b-unsaturated carboxylic acid derivatives– coumarins 193, 194– 1,3-dioxin-4-ones 198–200– endocyclic heteroatom 198–201– exocyclic heteroatom 201–203– lactams 192, 203–205

462j Index

– lactones 189–192, 202, 203– maleic anhydride 196, 197– [2þ2]-photocycloadditon 189–201– 4-pyrimidinones 200, 201– quinolones 194, 195– sulfur analogues 197, 198g ,d-unsaturated carboxylic acid 276– photoinduced electron-transfer

cyclization 276a,b-unsaturated-g ,d-epoxynitrile

reactions 257unsaturated hydrocarbons overoxidation 376a,b-unsaturated ketones see a,b-unsaturated

carbonylsa,b-unsaturated lactams

photocycloaddition 192a,b-unsaturated lactones

photocycloaddition 189–191UV spectra and photoreactivity 15

vl-valine 98– 4-benzoylphenyl ester chiral sensitizer 98vinylarene compounds 144– [2þ2] photocycloadditions of 144vinyl-biphenyls photocyclization 299N-vinylcarbazole, cyclodimerization 139vinyl cyclopropanes 260– photochemical rearrangement 260, 261vinylene carbonate, Paternò Büchi

reactions 229vinyl ethers Paternò Büchi reactions 222vinylogous amides 182– de Mayo reaction 182

– 4-hetero-2-cyclohexenones 185, 186– 4-hetero-2-cyclopentenones 183–185– [2þ2]-photocycloaddition 182vinylogous esters photocycloaddition 188

wWolff rearrangement 35, 111Wood�s lamp 6– for photochemical applications 6Woodward–Hoffmann rules 137, 219

yYang cyclization reaction 117, 153,

156, 307– in the formation of four membered

rings 153–156ylides 264,265– azomethine 258, 279– carbonyl 254–257, 279– push-pull 256

zzeolites 153– ene reactions with singlet oxygen 370– mediated asymmetric

hydroperoxidations 370– oxa-di-p-rearrangement 107Zimmerman rearrangement 96zwitterion intermediate in electrocyclic

reaction 261, 265– dehydrogenation 261– role of 265zwitterion-tricyclic route in thiophene

synthesis 392

Index j463