alkyne metathesis - chemistrymetathesis reaction in organic chemistry alkene metathesis kürti, l....
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Alkyne MetathesisCatalyst Development
and
Application in Total Synthesis
Meisam Nosrati
January 19th, 2011
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Metathesis Reaction
Metathesis: Exchange of bonds between the two reacting chemicalspecies.
Mortimer, E. C.; General Chemistry, Sixth Edition 1986.
Ag NO3 (aq) + Na Cl (aq) Ag Cl (s) + Na NO3 (aq)
H Cl (aq) + Na OH (aq) H OH (l) + Na Cl (aq)
H3C
O
OH
+ O
O
ONa (aq)Na
+ O
O
OHH
H3C
O
ONa (aq)
2 2
(CO2 (g) + H2O (l))
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Metathesis Reaction in Organic Chemistry
Alkene metathesis
Kürti, L. Czakó, B. Strategic Applications of Named Reactions in Organic Synthesis; Elsevier Academic Press: Burlington, MA 2005.
Alkyne metathesis
CatalystR1
R1R1
R1
R2
R2R2
R2
R2
R2R1
R12
R1 R1R1 R2
Catalyst
R2 R2
2
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Enyne Metathesis
Nitrile Alkyne Cross Metathesis (NACM)
Kürti, L. Czakó, B. Strategic Applications of Named Reactions in Organic Synthesis; Elsevier Academic Press: Burlington, MA 2005.Geyer, A. M.; Gdula, R. L.; Wiedner, E. S.; Johnson J. A. M. J. Am. Chem. Soc. 2007, 129, 3800.
R2H2C
R1
CatalystR1 R2
CH2
R1 N R1N
R2R2
Catalyst
R2 N R2N
R1R1
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Ring Closing Metathesis (RCM)
Hoveyda, H. A.; Cogen, A. D.; Xu, Z.; Houri, F. A.; J. Am. Chem. Soc. 1995, 117, 2943-2944.Fürstner, A.; Guth, O.; Rumbo, A.; Seidel, G. J. Am. Chem. Soc. 1999, 121, 11108.
Ring Closing Alkyne Metathesis (RCAM)
C CH2
C CH2
C
C+ H2C CH2
Catalyst
C C
C C
C
C+ C C
Catalyst
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Alkyne Metathesis Reaction Mechanism
Katz, T. J.; McGinnis, J. J. Am. Chem. Soc. 1975, 97, 1592.
(RO)3M
R1
R1
R
(RO)3M
R
(RO)3M
R1
R1
R
R1
M(OR)3+ R1R
R1
R1
(RO)3M
R2
R2
R1
(RO)3M
R1
(RO)3M
R2
R2
R1
R2
M(OR)3+ R2R1
R2
R2
R1 R1
R1 R2
Catalyst
R2 R2
Catalyst:
2
Carbyne ComplexM = Mo, W R = Alkyl, Aryl(RO)3M
R
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Katz, T. J.; McGinnis, J. J. Am. Chem. Soc. 1975, 97, 1592.Churchill, M. R.; Ziller, J. W.; Freudenberger, J. H.; and Schrock, R. R. Organometallics. 1984, 3, 1554.
Alkylidyne Mechanism Evidence
R
R(RO)3W
R
R
R
(RO)3W
(RO)3W
R
R
R
RR + (RO)3W RR +(RO)3W
W
Et
RORO OR
+ EtEt WRORO
ROEt
Et
Et R =
Crystals F3C
HF3C
RR
R
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First Reports on Alkyne Metathesis
Pannella, F.; Banks, R. L.; Bailey, G. C.; Chem. Commun. 1968, 1548.A. Mortreux, M. Blanchard, J. Chem. Soc., Chem. Commun. 1974, 786.
Mortreux Catalyst
6.8 % WO3 on Silica
200 °C - 450 °C+
56% 23%
+ polymeric products
21%
Resorcinol : Mo(CO)66:1 10 mol %
160 °C+ Resorcinol:2
55% 23.5% 21.5%
OH
OH
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Metallacycle Mechanism
Mortreux, A.; Coutelier, O. J. Mol. Catal. A. 2006, 254, 96.
Resorcinol : Mo(CO)66:1 10 mol %
160 °C+ Resorcinol:2
55% 23.5% 21.5%
OH
OH
R
R'
R
R'
M M
RR'
RR'
R
RR'
R'
RR'
R' R
M
M
R'
R'
R
R
MM
R
R
R'
R'
M = Active Metathesis Complex
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In Situ Generation of Carbyne Complexes
Huc, V.; Weihofen, R.; Jimenez, M. I.; Oulié, P.; Lepetit, C.; Lavigne, G.; Chauvin, R. New J. Chem.2003, 27, 1412.
• No solid evidence to support the formation of carbyne complex
• No solid evidence to support metallacycle mechanism
Mo(CO)6 + ArOH Mo MoOAr
ArO
ArOArO
OArOAr
C6H5Cl, 135 °C
Mo(OAr)3Mo(OAr)3
Me
Ph
Mo(OAr)3
Mo(OAr)3Ph
Me
Ph
MeMo(OAr)3
Mo(OAr)3
Ph
Me
Mo(OAr)3
Mo(OAr)3
Ph Me21 , 25 - 50 °C
Ph Ph +
1MS 4 Å
+H3CO OCH3
First Step:
Second Step:
ArOH = Cl OH
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Catalyst Development
Pschirer G. N.; Bunz, F. H. Tetrahedron Lett.1999, 40, 2481.Fürstner, A.; Guth, O.; Rumbo, A.; Seidel, G. J. Am. Chem. Soc. 1999, 121, 11108.
MeO
OMe
NC
Catalyst
Catalyst
Catalyst
MeO
OMe
NC
OMe
MeO
CN15%
72%
0%
Catalyst: 5 mol % Mo(CO)6, 140 °C, 1,2-Dicholorobenzene, 12-16h Cl OH
OO
OO
OO
OOCatalyst
p-Chlorobenzene as solvent,140 °C, 64%
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Catalyst Development
Fürstner, A.; .Guth, O.; Rumbo, A.; Seidel, G. J. Am. Chem. Soc. 1999, 121, 11108.Fürstner, A.; Stelzer, F.; Rumbo, A.; Krause, H. Chem. Euro. J. 2002, 8, 1856.
Catalyst: 5 mol % Mo(CO)6, 140 °C, Chlorobenzene Cl OH
O
O
O
O
NH
OSi
PhPh
O
O7
7
DecompositionStarting material recoveredStarting material recovered
Alcohol:
PMBO
PMBO OCH3
OPMB
PMBO
PMBO OCH3
OPMB
Chlorobenzene, microwave heating,
150 °C, 5 min
Mo(CO)6, 1
OH
CF3
1 =Cyclophaneintermediate
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Fischer Type Catalysts
Cr COCOOC
OC
CO
H3CO Ph
W COCOOC
OC
Cl
Ph
Fischer CarbeneComplex
Fischer CarbyneComplex
Nobelprize.org/nobel_prizes/chemistry/laureates/1973/fischer-lecture.pdf Fischer, O. E.; Maasaböl, A. J. Organomet. Chem. 1968, 12, P15.
(CO)5WCH3
OCH3+
O
OCH3H2N
Ether, 20 °C CH3OH(CO)5WCH3
HN
O
OCH3
(CO)5CrCH2
OCH3 90 °C, 1.5 h
Pyridine
H
HH3CO
H+ (C5H5N)Cr(CO)5
+
H
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Alkyne Metathesis with Fischer Carbynes
Fischer, E. O., Kreis, C., Kreiter, C. G., Müller, J., Huttner, G. and Lorenz, H., Angew. Chem.Int. Ed. 1973, 12, 564.Nobelprize.org/nobel_prizes/chemistry/laureates/1973/fischer-lecture.pdfFischer, O. E.; Ruhs, A.; Plabst, D. Naturforsch. Z. Teil B 32B 1977,7, 802.
Cr COCOOC
OC
Br
Ph
2Hexane, 30 °C
1.5 h
Cr COCOOC
OC
Br
Ph
m/z = 178
Cr COCOOC
OC
Br
Ph
+ Cr COCOOC
OC
Br
40 °C+ +
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Schrock Catalyst Development
McLain, J. S.; Wood, D. C.; Schrock, R. R. J. Am. Chem. Soc. 1979, 101, 4558.Wengrovius, H. J.; Sancho, J.; Schrock, R. R. J. Am. Chem. Soc. 1981, 103, 3932.
, Aromatic AlcoholMo COCOOC
OC
CO
CO
Schrock Catalyst: First highly efficient CarbyneComplex in Alkyne Metathesis.
Ta
CMe3H
tBuH2CtBuH2C
CH2tBuTa
tBuH2CtBuH2C
CH2tBu
WtBuH2C
tBuH2CCH2tBu tBuO
WOtBu
tBuO
Metathesis inactive Metathesis inactive
Metathesis inactive Metathesis activeSchrock Catalyst
W COCOOC
OC
Cl
Ph
Fischer CarbyneLow Oxidation State MetalPositive Carbyne Carbon
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The Role of the Alkoxide Ligand
Churchill, M. R.; Ziller, J. W.; Freudenberger, J. H.; Schrock, R. R. Organometallics 1984, 3, 1554.Schrock, R. R. Polyhedron 1995, 14, 3177.
Inactive
Metathesis
Polymerization
Polymerization
MotBuOtBuO
OtBuMoiPrO
iPrOOiPr
MoMe3CCH2OMe3CCH2O
OCH2CMe3WtBuO
tBuOOtBu
+ R'R
MAr(R)OAr(R)O
Ar(R)OR
R'
M = Mo, WR = Me R' = MeR = Et R' = EtR = Et R' = PrR= Pr R' = Pr
rt
R' +
MAr(R)OAr(R)O
O(R)Ar
MAr(R)OAr(R)O
O(R)Ar
R
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• Molybdenum complexes in general are less reactive than theirTungsten analogs.
• Molybdacyclobutadiene complexes are much prone to losealkyne than tungstacyclobutadiene complexes.
• Molybdenum catalysts are more likely to polymerize alkynes.Churchill, M. R.; Ziller, J. W.; Freudenberger, J. H.; Schrock, R. R. Organometallics 1984, 3, 1554.Schrock, R. R. Polyhedron 1995, 14, 3177.
The Role of the Alkoxide Ligand
Metallayclobutadiene
MetathesisMetathesis
Metathesis
Mo(2,6-iPrC6H3)O(2,6-iPrC6H3)O
O(2,6-iPrC6H3)
W(2,6-iPrC6H3)O(2,6-iPrC6H3)O
O(2,6-iPrC6H3)W(CF3)2CH3CO
(CF3)2CH3COOCCH3(CF3)2
Mo(CF3)2CH3CO(CF3)2CH3CO
OCCH3(CF3)2
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Theoretical Calculations of Alkyne Metathesis
Me
Me(R)3M
Me
Me
Me
(R)3M
(R)3M
Me
Me
Me
M = W R = OMe, NMe2
M = Mo R = OMe, CH2F
Me
Zhu, J.; Gia, J.; Lin, Z. Organometallics 2006, 25, 1812.
• B3LYP level of Density Functional Theory, LanL2DZ basis set for W and Mo atoms , 6-31G basis setfor C, N, F, O and H.
MoMeOMeO
OMe
WMeOMeO
OMeWMe2N
Me2NNMe2
MoFCH2OFCH2O
OCH2F
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Theoretical Calculations of W Carbyne Complexes
Zhu, J.; Gia, J.; Lin, Z. Organometallics 2006, 25, 1812.
WMeOMeO
OMe
[W]
[W]
[W]
[W]
[W]
[W] [W]
0.0
22.3
10.3
9.1 9.1
22.3
0.0
[W] = W(OMe)3
WMe2NMe2N
NMe2
Free energies in kcal/mol
[W] = W(NMe2)3
[W]
[W]
[W]
0.0
33.4
18.5
• B3LYP level of Density Functional Theory, LanL2DZ basis set for W and Mo atoms , 6-31G basis setfor C, N, F, O and H.
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Theoretical Calculations of Mo Carbyne Complexes
MoCH3OCH3O
OCH3
[Mo] = Mo(OMe)3
[Mo]
[Mo][Mo]
0.0
30.3
21.5
[Mo]23.9
[Mo]
16.9
[Mo]
30.3
[Mo]
0.0
MoFCH2OFCH2O
OCH2F
Zhu, J.; Gia, J.; Lin, Z. Organometallics 2006, 25, 1812.
• B3LYP level of Density Functional Theory, LanL2DZ basis set for W and Mo atoms , 6-31G basis setfor C, N, F, O and H.
Free energies in kcal/mol
[Mo]
[Mo]
[Mo]
[Mo] [Mo]
0.0
15.9
5.5
15.9
0.0
[Mo] = Mo(OCH2F)3
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Theoretical Calculations for W vs Mo Complexes
Zhu, J.; Gia, J.; Lin, Z. Organometallics 2006, 25, 1812.
[W]
[W]
[W]
[W]
[W]
[W] [W]
0.0
22.3
10.3
9.1 9.1
22.3
0.0
[W] = W(OMe)3
[Mo] = Mo(OMe)3
[Mo]
[Mo][Mo]
0.0
30.3
21.5
[Mo]23.9
[Mo]
16.9
[Mo]
30.3
[Mo]
0.0
Free energies in kcal/mol
MoCH3OCH3O
OCH3
WMeOMeO
OMe
• B3LYP level of Density Functional Theory, LanL2DZ basis set for W and Mo atoms , 6-31G basis setfor C, N, F, O and H.
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Schrock Catalyst Scope
Vintonyak, V. V.; Maier, M. E. Org. Lett. 2007, 9, 655 –658.Funk, L. R.; Nilson, G. M. Org. Lett. 2010, 12, 4912.
PhCl, 80 °C, 3 h77%
N
N
O
OTIPS
Boc
HON
N
O
OTIPS
Boc
HO
25 mol %
OMe
MeO
TIPSO
O
O
ROODMB
WtBuO
tBuOtBuO
toluene, 85 °C91%
OMe
MeO
O
TIPSO
ODMB
O
TBSO
WtBuO
tBuOtBuO
20 mol %
Nakadomarin A intermediate
Cruentaren A intermediate
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Schrock Catalyst Limitations
Fürstner, A.; .Guth, O.; Rumbo, A.; Seidel, G. J. Am. Chem. Soc. 1999, 121, 11108.Fürstner, A.; Muller, R.; Herrman, J.; Jean, L.; Bindl, M. Chem. Eur. J 2009, 15, 12310.Fürstner, A.; Alcarazo, M.; Hickmann, V. J. Am. Chem. Soc. 2010, 132, 11042.
OS
O
OO
NO
O
OO O
O
OO
O
OMe
MeO
TIPSO
O
O
OTHPTBSO
Thioethers
HeterocyclesUnsaturated Esters
Acetal Epoxide
Cruentaren A intermediate Ecklonialactone intermediate
tBuOW
OtButBuO
Schrock Catalyst
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Trisamido Molybdenum Complexes
(tBuO)3W W(tBuO)3 + 2 (tBuO)3W
(tBuO)3W W(tBuO)3 + N (tBuO)3W + (tBuO)3W N
(tBuO)3W W(tBuO)3 + N N N.R.
Schrock, R. R.; Listemann, L. M.; Sturgeoff, G. L. J. Am. Chem. Soc. 1982, 104, 4291.Laplaza, C. E.; Cummins, C. C. Science 1995, 268, 861.Wu, X.; Tamm, M. Beilstein. J. Org. Chem. 2011, 7, 82.
MoN
NN
+ N N
MoN N
N
N
22
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Fürstner, A.; Mathes, C.; Lehmann, W. C. J. Am. Chem. Soc. 1999, 121, 9453-9454.
Akyne Metathesis With Molybdenum TrisamidoComplexes
R21 , 10 mol %
CH2Cl2 (25 eq) / tolueneR R
R = H 60%R = CN 58%
RO
1 , 10 mol %
CH2Cl2 (25 eq) / tolueneR
OO
R
R = Me 59%R = THP 55%
2
MoN N
N+ Small Acetylenic molecule N.R.
1
MoN N
NCH2Cl2
Strongly endothermic reaction
1
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Fürstner, A.; Mathes, C.; Lehmann, W. C. J. Am. Chem. Soc. 1999, 121, 9453-9454.Fürstner, A.; Mathes, C.; Lehmann, W. C. Chem. Euro. J. 2001, 7, 5299.
Active Metathesis Species in the Reaction
MoN N
N CH2Cl2Mo
N NN
Cl
+
MoN N
N
H
1 2 3
MoN N
Ntoluene/CH2Cl2
5 min 80 °CAbruptly -20 °C
OCH3
+ Prepare a sample for Crystallography
Mo Mo
Cl
Cl
(tBu)ArN(tBu)ArN
NAr(tBu)NAr(tBu) Mo N
Cl
Cl
Ar(tBu)N
Ar(tBu)N
4 5
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OO
OO
OO
OOCatalyst
Fürstner, A.; Mathes, C.; Lehmann, W. C. J. Am. Chem. Soc. 1999, 121, 9453-9454.Fürstner, A.; Mathes, C.; Lehmann, W. C. Chem. Euro. J. 2001, 7, 5299.Chisholm, H. M.; Folting, K.; Hoffman, M. D.; Huffman, C. J. J. Am. Chem. Soc. 1984, 106, 6794.
Active Metathesis Species in the Reaction
Mo
RO
RORO
R'2 Mo MoOR
OR
RO
ROOR
OR
R'R'
R = CH2t-Bu, R' = HR = i-Pr, R' = H, Me
MoN N
N
H
35 mol %, , toluene 80 °C, 38%
Catalyst Dimerization:
3
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Fürstner, A.; Mathes, C.; Lehmann, W. C. Chem. Euro. J. 2001, 7, 5299.
Active species in Catalysis
• Halogenated Molybdenum complexes at different oxidationstate are able to catalyze metathesis reactions
Mo Mo
Cl
Cl
(tBu)ArN(tBu)ArN
NAr(tBu)NAr(tBu)
10 mol % , toluene 80 °C, 0%
MoN N
N
Cl
10 mol % , toluene 80 °C, 70%
Mo N
Cl
Cl
Ar(tBu)N
Ar(tBu)N
5 mol %, toluene, rt, 90%
MoN
NN
Br
10 mol %, toluene 80 °C, 79%
4 2
5
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Fürstner, A.; Mathes, C.; Lehmann, W. C. Chem. Euro. J. 2001, 7, 5299.
Substitution on the Aromatic Rings
MoN N
OMe
OMeN
MeO MeOOMeMeO
Cl
10 mol %, , toluene, 80 °C, 51%
MoN N
F
FN
F FFF
10mol%, 25 equiv CH2Cl2, toluene, 80 °C, 79%
MoN N
N
Cl
10 mol % , toluene, 80 °C, 70%
MoN N
N
10 mol % , 25 equiv CH2Cl2, toluene, 80 ˚C, 81%
OO
OO
OO
OOCatalyst
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Schrock Catalyst Limitations
Fürstner, A.; .Guth, O.; Rumbo, A.; Seidel, G. J. Am. Chem. Soc. 1999, 121, 11108.Fürstner, A.; Muller, R.; Herrman, J.; Jean, L.; Bindl, M. Chem. Eur. J 2009, 15, 12310.Fürstner, A.; Alcarazo, M.; Hickmann, V. J. Am. Chem. Soc. 2010, 132, 11042.
OS
O
OO
NO
O
OO O
O
OO
O
OMe
MeO
TIPSO
O
O
OTHPTBSO
Thioethers
HeterocyclesUnsaturated Esters
Acetal Epoxide
Cruentaren A intermediate Ecklonialactone intermediate
tBuOW
OtButBuO
Schrock Catalyst
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Trisamido Molybdenum Catalyst Scope
Fürstner, A.; Mathes, C.; Lehmann, W. C. J. Am. Chem. Soc. 1999, 121, 9453-9454.
OS
O
OO
NO
O
OO
Thioethers
Unsaturated Esters
O
1, 10 mol %, CH2Cl2, Toluene, 80 °C, 84%
1, 10 mol %, CH2Cl2, Toluene, 80 °C, 88%
Heterocycles1, 10 mol%, CH2Cl2, Toluene, 80 °C, 83%
MoN N
N
Catalyst: 1
O8
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Fürstner, A.; Muller, R.; Herrman, J.; Jean, L.; Bindl, M. Chem. Eur. J 2009, 15, 12310.Fürstner, A.; Alcarazo, M.; Hickmann, V. J. Am. Chem. Soc. 2010, 132, 11042.
Trisamido Molybdenum Catalyst Scope
O
O
O
1 , 20-40 mol %, CH2Cl2, toluene, 50-89%2 Unsuitable
Ecklonialactone total synthesis
OMe
MeOTIPSO
O
O
OTHPTBSO
1 10 mol %, CH2Cl2, toluene, 80 °C, 87%2 Unsuitable
Cruentaren A intermediate
MoN N
N
Catalyst: 1tBuO
WOtBu
tBuO
2
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Trisamido Molybdenum Catalyst Scope
Fürstner, A.; .Guth, O.; Rumbo, A.; Seidel, G. J. Am. Chem. Soc. 1999, 121, 11108.Fürstner, A.; Flügge, S.; Larionov, O.; Takahashi, Y.; Kubota, T.; Kobayashi.; I. J. Chem. Eur. J. 2009, 15, 4011.Fürstner, A.; Mathes, C.; Lehmann, W. C. J. Am. Chem. Soc. 1999, 121, 9453-9454.
N
O
R
1, 10 mol %, CH2Cl2, toluene, 80 °CR = H 0%, R=Me 72%2, 5 mol %, Chlorobenzene, 80 °CR = H 62%R = Me 72%
7RO
OOTBS
O O
1, 30 mol %, CH2Cl2, toluene, 80 °C, 84%
Amphidinolide V intermediate
MoN N
N
Catalyst: 1tBuO
WOtBu
tBuO
2
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Silyloxy based Molybdenum Catalysts
Freudenberger, J. H.; Schrock, R. R. Organometallics 1986, 5, 398. Gdula, R. L.; Johnson, M. J. A. J. Am. Chem. Soc. 2006, 128, 9614.Wu, X.; Tamm, M. Beilstein. J. Org. Chem. 2011, 7, 82.
ROW
ORRO RO
WOR
RO
N
+
ROW
ORRO
N
ROW
ORRO
+
R =
R = C(CF3)(CH3)2
N
N
ROMo
ORRO
N
ROMo
ORRO + N
R = C(CF3)2Me, C(CF3)3
95 °C, 14.5 h
hexane
toluene
Metathesis inactive
Metathesis inactive
Metathesis active
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Bindl, M.; Stade, R.; Heilmann, E. K.; Picot, A.; Goddard, R.; Fürstner, A. J. Am. Chem. Soc. 2009, 131, 9468.Heppekausen, J.; Stade, R.; Goddard, R.; Fürstner, A. J. Am. Chem Soc. 2010, 132, 11045.
Nitrido Molybdenum Silyloxy Based Catalysts
Mo
N
Ph3SiO
Ph3SiO
N
OSiPh3
Mo
NPh3SiO
Ph3SiO
OSiPh3
N
N
Air StableStable to be weighed in Air
Mo
N
NMe3SiO
Me3SiOSiMe3
SiMe3
1)Ph3SiOH (3 equiv), toluene, 80 °C
then Pyridine (5eq)81%
Mo
N
Ph3SiO
Ph3SiON
OSiPh3
1,10-Phenantroline, toluene/Et2O, 81%
Mo
NPh3SiO
Ph3SiO
OSiPh3
N
N
MnCl2, toluene, 80 °CAir Stable
Mo
N
Ph3SiO
Ph3SiOOSiPh3
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Scope of Nitrido Silyloxy Based Catalysts
Smith, J. B.; Sulikowski, A. G.; Angew. Chem. Int. Ed 2010, 49, 1599.Funk, L. R.; Nilson, G. M. Org. Lett. 2010, 12, 4912.
20 mol %
PhMe, 80 °C, 16 h, 80%
N
N
O
OTIPS
Boc
HO
N
N
O
OTIPS
Boc
HOMo
N
Ph3SiO
Ph3SiO OSiPh3
N
Nakadomarin A intermediate
N
N
H
H
H
H
N
N
H
H H H
Ph3SiOH (3 equiv), toluene, 80 °C, 63%
Mo
N
NMe3SiO
Me3SiOSiMe3
SiMe3
Haliclonacyclamine CIntermediate
( 50 mol % Catalyst)
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Scope of Silyloxy Based Carbyne Catalysts
Fürstner, A.; Micoine, K. J. Am. Chem. Soc. 2010, 132, 14064.Heppekausen, J.; Stade, R.; Goddard, R.; Fürstner, A. J. Am. Chem Soc. 2010, 132, 11045.
Mo
Ph
Ph3SiO
Ph3SiO
OSiPh3
OEt2
1,10-Phenantroline, toluene/Et2O, 81%
Mo
Ph
Ph3SiO
Ph3SiO
OSiPh3
N
N
MnCl2, toluene, 80 °CAir Stable
5 mol %
toluene, MS 5 Å, 80 °C, 95 %O
OTES OO O
OTESMo
Ph
Ph3SiO
Ph3SiO OSiPh3
OEt2
Lactimidomycin intermediate
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Fürstner, A.; Alcarazo, M.; Hickmann, V. J. Am. Chem. Soc. 2010, 132, 11042.
Scope of Silyloxy Based Carbyne Catalysts
O
O
O
OO
O
Catalyst
Catalyst
WOtBu
OtBuOtBu
Mo
N
Ph3SiO
Ph3SiO OSiPh3
N
20-40 mol %, CH2Cl2/toluene, 50-89 %
Mo
Ph
Ph3SiO
Ph3SiO OSiPh3
OEt2
MoN N
N
Unsuitable
Unsuitable 5 mol %, toluene, 5Å ,80%
Ecklonialactone intermediate
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Ring Closing Alkyne Metathesis (RCAM)in Natural Product total Synthesis
C CH2
C CH2
+ H2C CH2C
C H
HRCM C
C
H
H+
RCM
RCAM Z- selective olefin synthesis
C C
C C
C
C+ C C
RCAMLindlar
Reduction CC
H
H
Fürstner, A.; Guth, O.; Rumbo, A.; Seidel, G. J. Am. Chem. Soc. 1999, 121, 11108.
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E-Selective Olefin Synthesis
(EtO)3SiH
(Cp*Ru[MeCN)]PF6
C C
C C
C
C+ C C
RCAM
C
C Si(OEt)3
H AgF
THF/MeOH
C
C H
H
Lacombe, F. Radkowski, K.; Günter, S.; Fürstner, A. Tetrahedron 2004, 60, 7315.
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Ono, K.; Nakagawa, M.; Nishida, A. Angew. Chem. Int. Ed. 2004, 42, 2020.Funk, L. R.; Nilson, G. M. Org. Lett. 2010, 12, 4912.
RCM
RCAM
RuPhPCy3
PCy3Cl
Cl
20 mol %, CH2Cl2 reflux 24 h
N
N
O
H
O
ON
N
O
H
O
O
Z/E: 1:1.8 26%:46%
Nakadomarin A intermediate
Catalyst
PhCl, 80 °C, 3 h77%
20 mol %PhMe, 80 °C,
16 h, 80%
N
N
O
OTIPS
Boc
HON
N
O
OTIPS
Boc
HO
(tBuO)3W Mo
N
Ph3SiO
Ph3SiO OSiPh3
N
N
N
O
OH
Boc
HO
1) H2, Lindlar
2) TBAF, 80%Two steps
O
25 mol % OrCatalyst:
Nakadomarin Aintermediate
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RCM
Nicolaou, K. C.; He, Y.; Vourloumis, D.; Vallberg, H.; Roschangar, F.; Sarabia, F.; Ninkovic, S.; Yang,Z.; Trujillo, J. I. J. Am. Chem. Soc. 1997, 119, 7960.
O
O O
HO N
S
OTBSO
O
N
S
OTBS
O
HO
O
O O
HO N
S
OH
RuPhPCy3
PCy3Cl
Cl
0.1 equiv, CH2Cl2, 25 °C, 20 h
CatalystCatalyst:
46% 39%Epothilone C intermediate
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RCAM
Fürstner, A.; Mathes, C.; Grela, K.; Chem. Commun. 2001, 1057.
O
O O
TBSON
S
OTBS O
TBSO
N
S
OTBS
O
NMo
NN
10 mol%
toluene/CH2Cl2, 80 °C8 h, 80 %
Lindlar, H2, CH2Cl2,
O
O O
TBSON
S
OTBS
O
Quant
Epothilone C intermediate
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Alkyne Activity in Metathesis Reactions
RCAM in the presence of Alkene
RCM in the presence of triple bond
Ono, K.; Nakagawa, M.; Nishida, A. Angew. Chem. Int. Ed. 2004, 42, 2020.Fürstner, A.; Micoine, K. J. Am. Chem. Soc. 2010, 132, 14064.
BocN
N
O
H
O
Co2(CO)8
RuPh
PCy3Cl
Cl
NMesMesN
CH2Cl2 (1mM)reflux, 1.5 h, 83 %
25 mol %BocN
N
O
H
O
Co2(CO)8
Nakadomarin A intermediate
5 mol %
toluene, MS 5 Å, 80 °C, 95 %O
OTES OO O
OTESMo
Ph
Ph3SiO
Ph3SiO OSiPh3
OEt2
Lactimidomycin intermediate
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Summary
• High oxidation state Tungsten and Molybdenum Carbynes are thecatalysts that has been used so far for Alkyne metathesis in thenatural product total synthesis.
• Metathesis activity of a carbyne comlplex highly depends on thecontrol of the lewis acidity of the catalyst, which can be optimized bythe electronic effects of ligands.
• The choice of a catalyst for Alkyne metathesis depends on itsfunctional group tolerancy.
• However, Alkyne Metathesis is much less used than AlkeneMetathesis in natural product total synthesis, it can be acomplementary approach to selectivity control of RCM reactions.
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Acknowledgement
AdvisorsProf.Geiger, Prof.Borhan
ProfessorsProf.Maleczka, Prof.Odom, Prof.Jackson
Dr.Vasileiou
Best LabmatesRoozbeh, Ipek, Arvind, Carmin, Wenjing,Atefeh, Sarah, Kumar, Tanya, Mercy, Calvin,Camille, Aman, Nastaran, Susan, Rafida,Remi.
And You
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Chuck-Harrold Mechanism
Chung, W. L.; Wu, Y.; Trost, M.; B.; Ball, T. Z. J.Am.Chem.Soc. 2003, 125, 11578.
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Reductive Recycle strategy for TrisamidoMolybdenum complexes
Zhang, W.; Kraft, S.; Moore S. J. Am. Chem. Soc. 2004, 126, 309.
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New Class of Carbyne catalysts
MoN N
N
Cl
Mo(CO)6
Mo
Ph
Ph3SiOOSiPh3Ph3SiOOEt2
tBuOW
OtButBuO
1
2
3
4
OO
OO
OO
OOCatalyst
73%4, 2mol%, toluene, rt, MS 5Å
70%3, 10mol%, toluene, 80oC
73%2, 5mol%, Cholorobenzene, 80oC
64%1, 5mol%, p-Chlorophenol(1eq),Cholorobenzene, 140oC
YieldCatalyst
Fürstner, A.; Guth, O.; Rumbo, A.; Seidel, G. J. Am. Chem. Soc. 1999, 121, 11108.Fürstner, A.; Mathes, C.; Lehmann, W. C. J. Am. Chem. Soc. 1999, 121, 9453-9454.Heppekausen, J.; Stade, R.; Goddard, R.; Fürstner, A. J. Am. Chem Soc. 2010, 132, 11045.
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W NO
O
N
N
tBu
tBu
F3C
F3CF3C
F3C
Wu, X.; Tamm, M. Beilstein. J. Org. Chem. 2011, 7, 82.Lysenko, S.; Haberlag, B.; Daniliuc, G. C.; Jones, G. P.; Tamm, M. Chem. Cat. Chem. 2011, 3, 115.
Imidazoline-2-Iminato Tungsten Catalysts
Tri(tert-butoxy)silanolate-Supported TungstenBenzylidyne Complex
W OO
O
Si
Si
Ph
SiOtButBuO
OtButBuO
tBuO
tBuOtBuO OtBu
OtBu
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Imidazoline iminato Tungsten vs Shrock catalyst
1
R = H
R = CH3
(tBuO)3W
W
CMe3
NO
O
NN
tBu
tBu
F3C
F3CF3C
F3C
R Hexane, rt350 mbar
R
RR = HR = CH3
Catalyst 1mol%
Beer, S.; Hrib, G. C.; Jones, G. P.; Brandhorst, K.; Grunenberg, J.; Tamm, M.Angew. Chem. Int. Ed. 2007, 46, 8890.