1

Supplementary Material (ESI) for Chemical Communication

This journal is (c) The Royal Society of Chemistry 2009

Palladium Catalyzed Domino Reaction of 1,4-Disubstituted 1,2,3-Trizoles

via Double C-H Activation: One-pot Synthesis of

Triazolo [1,5-f] Phenanthridines

Avnish Kumar,a Sundar S. Shindea, Dharmendra Kumar Tiwari, a Balasubramanyam Sridhar b and

Pravin R. Likhar* a

Table of contents

1 General Information 2

2 General Experimental Procedures 2-3

3 Palusible mechanism for heterocondensation 3

4 1H and 13C Spectra of compounds (2a-2t) 4-22

5 1H and 13C Spectra of compounds (4aa-4ae) 22-38

6 X-ray Single Crystal Structure of 2a 39-40

7 References 40

Electronic Supplementary Material (ESI) for RSC Advances.This journal is © The Royal Society of Chemistry 2016

2

Experimental Section

General information:

All reagents were purchased from commercial suppliers and used without further purification.

All experiments were carried out under nitrogen atmosphere. All the solvents used for the

reaction were distilled before use. The product purification by column chromatography was

accomplished using silica gel 100-200 mesh. Analytical TLC was performed with Merck silica

gel 60 F254 plates, and the products were visualized by UV detection. The 1H NMR and 13C

NMR spectra were recorded on a Bruker-Avance (300 MHz); Inova (400 MHz) and Avance

(500 MHz) spectrophotometer using CDCl3 and TMS as the internal standard. Chemical shifts

(δ =) are reported in ppm using TMS as an internal standard, and spin -spin coupling constants

(J) are given in Hz. Multiplicities in the 1H NMR spectra are described as: s = singlet, d =

doublet, t = triplet, q = quartet, qt = quintet, m = multiplet, bs = broad singlet; coupling

constants are reported in Hz. Low (MS) and high (HRMS) resolution mass spectra were

recorded on a Waters 2695 and Thermo Scientific Exactive spectrometer respectively and

mass/charge (m/z) ratios are reported as values in atomic mass units. All the melting point is

uncorrected.

General experimental procedure for the synthesis of 2-iodophenyl 4-alkyl/aryl-1H 1,2,3-triazole

(1a-1y)1:

To a stirred solution of 2-iodoaniline (3.0 mmol) in 4N HCl (10 mL) was added NaNO2 (0.82 gm, 12

mmol) slowly in portions over a period of 15 mins at 0°C. The reaction mixture was allowed to stir at

same temperature for another 30 min. To the above reaction mixture sodium azide (0.59 gm, 9.0 mmol)

was slowly added in portions and the mixture allowed to come to the room temperature and stirred for

4-12 hrs (monitored by TLC using hexane: ethyl acetate (8:2) solvent). The reaction mixture was

successively diluted with water. The aqueous layer was extracted with ethyl acetate (3 x 60 mL), and

combined organic layers were washed with water, followed by brine, dried over Na2SO4 and

concentrated under reduced pressure to obtain crude azide derivatives which was carried forward for the

3

click reaction without any further purification. To a solution of crude azide (0.49 gm, 2.0 mmol) and

terminal alkyl/aryl acetylene (2.0 mmol) in DMF (10 mL) was added CuI (10 mol%) and the mixture

was heated at 100 °C for 8 hrs. The aqueous layer was extracted with ethyl acetate (3 x 40 mL), and

combined organic layer was washed with water (3 x 50 mL), followed by brine, dried over Na2SO4 and

concentrated under reduced pressure to obtain crude triazole derivatives in quantitative yields.

Plausible mechanism for hetero aryl cross coupling: Based on the literature reports2 a plausible

mechanism for the cross coupling reaction between 1a and 3a in the presence norbornene can be

rationalized (depicted in ESI-scheme-1). Intially, the aryl iodide (3a) oxidatively insert to Pd(0) to give

Pd(II) (A) species and then norbornene inserts into A to give corbopalladacyclic intermidiate (B) after

removal of HI in the presence of base. The oxidative addition of substitiuted triazole 1a to

corbopalladacyclic intermidiate (B) to give Pd(IV) intermidiate (C). Aryl-aryl bond formation takes

place via reductive elimination and removal of nonbornene to give (D) which led to the formation of

desired heterocoupled product (4aa) via intramolecualr C-H activation.

ESI-scheme-1: Plausible mechanism for heterocoupling

I

PdI

N N

N

C4H9

PdI

NN

NC4H9

Pd(0)

Pd

I

N

N N

C4H9

3a

1a

4aa

(A)

(B)

(D)

Pd

N

NN

C4H9

(C)

I

4

N

N N

N

NN

2a, 1H NMR,

CDCl3, 500 MHz

N

N N

N

NN

2a, 13C NMR,

CDCl3, 100 MHz

5

N

N N

N

NN

2b, 1H NMR,

CDCl3, 500 MHz

N

N N

N

NN

2b, 13C NMR,

CDCl3, 100 MHz

6

N

N N

N

NN

2c, 1H NMR,

CDCl3, 400 MHz

N

N N

N

NN

2c, 13C NMR,

CDCl3, 100 MHz

7

-0.50.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.5

PPM

2.01

2.02

4.02

1.03

0.98

0.96

0.88

0.95

1.95

1.04

0.93

1.00

0.986

0.992

1.000

1.004

1.013

1.062

1.071

1.076

1.080

1.092

1.097

1.100

1.235

1.238

1.243

1.246

1.248

1.262

1.266

2.101

2.110

2.115

2.122

2.131

2.135

2.143

2.299

2.304

2.312

2.318

2.326

2.332

2.338

6.201

6.204

6.223

6.225

7.222

7.226

7.240

7.244

7.247

7.474

7.608

7.612

7.616

7.619

7.628

7.631

7.634

7.637

7.640

7.655

7.658

7.775

7.794

7.814

8.783

8.786

8.804

8.807

8.845

8.848

8.865

8.868

6.06.57.07.58.08.59.0

PPM

0.96

0.88

0.95

1.95

1.04

0.93

1.00

1.92.02.12.22.32.42.5

PPM

1.03

0.98

2d 1H NMR,

CDCl3, 400 MHz

N

N N

N

NN

2d 13C NMR,

CDCl3, 100 MHz

N

N N

N

NN

8

9

2f 1H NMR,

CDCl3, 400 MHz

N

N N

N

NN

2f 1H NMR,

CDCl3, 400 MHz

N

N N

N

NN

10

2g 1H NMR,

CDCl3, 500 MHz

N

N N

N

NN

2g 13C NMR,

CDCl3, 100 MHz

N

N N

N

NN

11

2h 1H NMR,

CDCl3, 500 MHz

NN N

N

OMe

NNMeO

2h 13C NMR,

CDCl3, 100 MHz

NN N

N

OMe

NNMeO

12

2i 1H NMR,

CDCl3, 500 MHz

N

N N

N

NN

O

O

2i 1H NMR,

CDCl3, 500 MHz

N

N N

N

NN

O

O

13

14

15

N

N N

N

NN

FF

2l,1H, NMR

CDCl3, 500 MHz

16

17

18

19

20

NN N

NNN

Cl

Cl

2q, 1H NMRCDCl3, 500 MHz

21

N

N N

N

NN

2r, 1H NMR,CDCl3, 500 MHz

N

N N

N

NN

2r, 13C NMR,CDCl3, 100 MHz

22

2s, 1H NMRCDCl3, 500 MHz

NN N

NNN

23

24

25

3.02

2.06

1.98

3.06

2.03

1.02

2.00

1.01

1.06

1.04

0.94

0.000

0.072

0.900

0.918

0.937

1.359

1.377

1.396

1.415

1.607

1.723

1.743

1.763

2.766

3.180

3.200

3.220

7.261

7.467

7.485

7.549

7.553

7.573

7.588

7.591

7.637

7.640

7.658

7.661

7.676

7.679

8.260

8.341

8.343

8.743

8.746

8.764

8.767

1.02

2.00

1.01

1.06

1.04

0.94

13.906

22.631

23.478

29.529

31.394

76.723

77.041

77.358

117.243

120.421

122.644

123.440

123.563

127.149

128.273

129.059

129.420

131.533

134.796

143.560

26

2.99

3.03

3.06

1.06

1.04

1.97

1.05

1.01

1.07

1.00

1.449

1.466

2.769

3.533

3.550

3.566

3.583

3.600

3.617

3.634

7.261

7.466

7.484

7.538

7.543

7.556

7.562

7.573

7.577

7.581

7.626

7.629

7.647

8.242

8.324

8.344

8.732

8.735

8.752

8.755

1.04

1.97

1.05

1.01

1.07

1.00

1.06

23.145

23.332

27.582

76.752

77.070

77.387

117.185

120.325

122.636

123.492

126.745

127.058

128.108

129.237

129.387

131.453

134.758

148.866

N

N N13C NMR, CDCl3,

100 MHz; 4xa

27

2.94

2.98

2.04

1.02

1.97

0.98

1.01

1.03

1.00

2.103

2.816

5.682

7.508

7.522

7.609

7.624

7.639

7.685

7.701

7.715

8.338

8.388

8.404

8.800

8.816

1.02

1.97

0.98

1.01

1.03

1.00

N

N N1H NMR, CDCl3,

500 MHz; 4ja

OAc

N

N N1H NMR, CDCl3,

100 MHz; 4ja

OAc

28

3.00

2.97

2.01

1.00

2.00

1.00

1.03

1.02

0.97

2.930

3.388

5.079

7.261

7.488

7.503

7.567

7.582

7.594

7.596

7.598

7.610

7.613

7.657

7.660

7.674

7.676

8.367

8.383

8.384

8.789

8.791

8.805

8.808

1.00

2.00

1.00

1.03

1.02

0.97

22.401

57.752

68.686

76.764

77.081

77.399

117.298

120.518

122.571

122.632

123.565

127.413

128.765

129.133

129.222

129.424

130.999

131.762

136.225

139.375

N

N N1H NMR, CDCl3,

500 MHz; 4ya

OMe

13C NMR, CDCl3,

100 MHz; 4ya

N

N NOMe

29

3.02

1.03

1.03

1.08

1.05

1.03

1.09

0.99

1.00

2.844

7.261

7.514

7.529

7.596

7.612

7.627

7.631

7.633

7.645

7.648

7.650

7.662

7.664

7.714

7.716

7.728

7.730

7.733

7.745

7.747

8.343

8.359

8.453

8.469

8.470

8.482

8.843

8.845

8.859

8.861

1.03

1.03

1.08

1.05

1.03

1.09

0.99

1.00

23.585

76.785

77.039

77.293

117.190

120.902

121.718

122.445

123.880

127.440

128.300

128.780

129.604

130.413

130.690

130.966

131.095

135.756

30

3.08

5.07

2.00

3.06

1.01

1.01

2.00

1.00

1.00

1.00

0.94

1.254

1.367

1.386

1.390

1.402

1.426

1.431

1.601

1.604

1.615

1.768

1.780

1.820

1.826

1.850

1.874

1.893

1.989

2.014

2.768

3.152

3.159

3.165

3.175

3.181

3.188

3.197

3.204

3.211

7.261

7.475

7.490

7.540

7.548

7.555

7.563

7.571

7.578

7.631

7.646

7.661

8.245

8.327

8.343

8.732

8.748

1.01

2.00

1.00

1.00

1.00

0.94

23.115

26.091

26.932

33.393

37.584

76.736

77.054

77.371

117.209

120.332

122.659

123.501

126.802

127.048

128.058

129.255

129.391

131.429

131.500

134.781

148.163

13C NMR, CDCl3,

100 MHz; 4fa

N

N N

31

14.196

22.984

29.949

33.366

54.839

76.790

77.044

77.298

109.558

114.261

115.119

117.267

121.832

123.803

125.463

126.978

129.158

129.462

129.632

131.698

144.581

155.709

13C NMR, CDCl3,

100 MHz; 4ab

N

N N

C4H9

OMe

32

3.00

3.01

2.05

1.01

2.00

1.00

1.01

1.03

0.98

2.124

3.996

5.795

7.087

7.103

7.264

7.609

7.611

7.627

7.643

7.699

7.701

8.000

8.017

8.357

8.372

8.373

8.808

8.810

8.825

8.827

1.01

2.00

1.00

1.01

1.03

0.98

33

13.882

22.746

27.756

30.284

52.990

76.737

77.054

77.372

117.338

121.605

121.689

123.542

125.772

126.443

127.360

127.726

129.458

130.094

130.175

130.376

131.682

144.991

168.712

2.99

2.03

2.00

2.98

1.01

2.01

1.03

1.07

1.05

1.00

0.898

0.917

0.935

1.315

1.333

1.352

1.370

1.389

1.408

1.693

1.809

1.828

1.847

1.866

1.885

2.828

2.848

2.867

3.995

7.264

7.578

7.581

7.599

7.616

7.619

7.650

7.669

7.689

7.708

7.726

7.729

7.956

7.958

7.975

7.977

8.334

8.354

8.512

8.531

8.758

8.760

8.778

8.780

1.01

2.01

1.03

1.07

1.05

1.00

2.00

13C NMR, CDCl3,

100 MHz; 4ac

N

N N

C4H9

COOMe

34

N

N N

COOMe

1H NMR, CDCl3,

500 MHz, 4xc

N

N N

COOMe

13C NMR, CDCl3,

125 MHz, 4xc

35

3.05

2.99

2.05

0.99

2.06

0.99

1.08

1.07

1.00

1.609

2.012

4.016

5.488

7.263

7.655

7.714

7.729

7.730

7.734

7.746

7.750

7.753

8.078

8.081

8.093

8.096

8.386

8.402

8.583

8.585

8.600

8.602

8.806

8.808

8.823

8.825

0.99

2.06

0.99

1.08

1.07

1.00

N

N N

1H NMR, CDCl3,

500 MHz; 4jc

COOMe

OAc

36

3.02

2.89

1.94

2.16

1.07

2.97

1.01

1.00

1.03

1.02

1.06

0.98

0.98

0.000

1.359

1.376

1.395

1.592

1.758

1.765

1.782

1.870

1.883

1.888

1.957

1.983

2.722

2.729

2.735

2.745

2.752

2.758

2.768

2.775

4.008

7.262

7.591

7.594

7.608

7.622

7.625

7.647

7.662

7.678

7.700

7.702

7.717

7.731

7.733

7.963

7.966

7.978

7.981

8.343

8.359

8.519

8.534

8.769

8.771

8.786

8.788

1.01

1.00

1.03

1.02

1.06

0.98

0.98

26.017

26.722

32.346

36.791

53.007

76.799

77.053

77.307

117.376

121.574

121.979

123.479

125.435

125.834

127.284

127.655

129.549

129.867

130.153

130.545

131.741

149.639

168.610

37

38

3.07

2.09

2.02

2.06

2.95

1.03

2.01

2.98

1.00

0.840

0.855

0.870

1.317

1.332

1.743

1.755

1.758

1.774

1.789

1.804

3.144

3.161

3.175

7.544

7.560

7.575

7.586

7.588

7.595

7.603

7.605

7.614

7.644

7.660

7.675

7.888

7.893

7.896

7.911

7.929

8.216

8.235

8.249

8.254

8.279

8.296

8.775

8.792

2.95

1.03

2.01

2.98

1.00

2.06

13.877

22.706

29.497

31.600

76.853

77.108

77.362

117.130

119.877

120.509

122.317

123.737

125.925

126.685

127.067

127.121

127.196

128.013

128.223

129.288

129.480

131.435

133.044

143.222

13C NMR, CDCl3,

125 MHz; 4ae

N

N N

C4H9

39

X-Ray Crystallographic Study:

ORTEP structure of 2a

X-ray data of 2a compound was collected at room temperature using a Bruker Smart Apex CCD

diffractometer with graphite monochromated MoKα radiation (λ=0.71073Å) with ω-scan method.2

Preliminary lattice parameters and orientation matrices were obtained from four sets of frames.

Integration and scaling of intensity data were accomplished using SAINT program.3 The structures were

solved by Direct Methods using SHELXS3 and refinement was carried out by full-matrix least-squares

technique using SHELXL.4 The crystal was twinned, and the structure was refined using a HKLF5 file

containing data for two twin domains, with a refined BASF of 0.31.Anisotropic displacement

parameters were included for all non-hydrogen atoms. The atoms C21-C24 were disordered over two

sites (C21/C22/C23/C24 and C211/C221/C231/C241). The site-occupancy factors of disordered atoms

were refined to 0.790(9) and 0.210(9). DELU and DFIX constraints were applied to the disordered

atoms. All H atoms were positioned geometrically and treated as riding on their parent C atoms [C-H =

0.93-0.97 Å and Uiso(H) = 1.5Ueq(C) for methyl H or 1.2Ueq(c) for other H atoms]. The methyl groups

were allowed to rotate but not to tip.

Crystal Data for 2a: C24H26N6 (M =398.51): triclinic, space group P-1 (no. 2), a = 7.619(2) Å, b =

9.692(3) Å, c = 15.884(5) Å, α = 75.952(5)°, β = 79.091(5)°, γ = 71.433(5)°, V = 1070.6(6) Å3, Z = 2,

T = 294(2) K, μ(MoKα) = 0.077 mm-1, Dcalc = 1.236 g/mm3, 9893 reflections measured (4.522 ≤ 2Θ ≤

40

50), 9893 unique which were used in all calculations. The final R1 was 0.0906 (I > 2σ(I)) and wR2 was

0.2933 (all data). CCDC 1408841 contains supplementary Crystallographic data for the structure. These

data can be obtained free of charge at www.ccdc.cam.ac.uk/conts/retrieving.html [or from the

Cambridge Crystallographic Data Centre (CCDC), 12 Union Road, Cambridge CB2 1EZ, UK; fax:

+44(0) 1223 336 033; email: deposit@ccdc.cam.ac.uk].

References

1. G. C Senadi, W-P Hu, S. S. K. Boomiathan and J-J Wang, Adv. Synth. Catl. 2013, 355, 3679.

2. (a) M. Catellani, F. Frignani, A. Rangoni, Angew. Chem. Int. Ed. 1997, 36, 119. (b) M. Catellani,

M. C. Fagnola, Angew. Chem. Int. Ed. 1994, 33, 2421. (c) “Novel Methods of Aromatic

Functionalization Using Palladium and Norbornene as a Unique Catalytic System”, M. Catellani,

Top Organomet Chem, 2005, 14, 21-53.

3. SMART & SAINT. Software Reference manuals. Versions 6.28a & 5.625, Bruker Analytical X-

ray Systems Inc., Madison, Wisconsin, U.S.A., 2001.

4. Sheldrick, G. M. SHELXS97 and SHELXL97, Programs for crystal structure solution and

refinement; University of Gottingen: Germany, 1997.