Supporting Information Ruthenium Catalyzed Oxidative Homocoupling of Arylboronic Acids in Water: Ligand Tuned Reactivity and Mechanistic Study Deepika Tyagi, Chinky Binnani, Rohit K. Rai, Ambikesh D. Dwivedi, Kavita Gupta, Pei- Zhou Li, Yanli Zhao and Sanjay K. Singh*,, Discipline of Chemistry, School of Basic Sciences, and Centre of Material Science and Engineering, Indian Institute of Technology (IIT) Indore, Indore, 452020, Madhya Pradesh, India Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
Table S1. Comparative table for the homocoupling reactions of phenylboronic acid. entry substrate catalyst additive/ base 1 Sodium p- toluenesulfinate PdCl2 O2/ Cu(OAc)2 (20 mol%) solvent temp / time Water 100 C/ 24h yield ref. % (2a) 85 S1 2 Aryliodine diacetates Pd(OAc)2 Cu(OAc)2 (1 equiv.)/ K2CO3 (1.5equiv.) DMF 110 C/ 20 h 52 S2 3 Phenylboronic acid [Pd(phbz) (OAc)(PPh3)] Air THF rt/ 30 min 70 S3 4 Phenylboronic acid Au(III) schiff base complex Air xylene 130 C/ 24 h 99 S4 5 Phenylboronic acid [Rh(PPh3)3Cl] Air / TEMPO Dioxane / water 130 C/ 1 h 53 S5 6 4-Bromophenyl boronic acid [TeFe3(CO)9 Cu2(Me2Im)2] complex Cu loading (0.5 1 mol%) MeOH rt/ 2 h 88 S6 7 4-Methylphenyl boronic acid 8 Phenylboronic acid 9 Phenylboronic acid [Cu(BDC)] (100 mg) [Cu2 β- CD/Fe3O4] (10 mol%) [Cu2 β- Cyclodextrin] complex (0.1 equiv.) Air THF rt/ 16 h 93 S7 Air DMF rt/ 3 h 90 S8 Air DMF rt/ 14 h 83 S9
Table S2. Selected bond lengths [Å] for [Ru]-3 Ru1 C1 2.162(4) Ru1 C2 2.164(5) Ru1 C6 2.176(4) Ru1 C3 2.178(5) Ru1 C5 2.179(4) Ru1 N1 2.181(3) Ru1 C4 2.188(5) Ru1 Cl1 2.4022(11) Ru1 Cl2 2.4217(10) N1 C7 1.438(5) N1 H1B 0.8900 N1 H1A 0.8900 C7 C12 1.392(6) C7 C8 1.395(5) C8 C9 1.403(7) C8 C14 1.503(7) C12 C11 1.388(6) C12 C13 1.504(6) C6 C1 1.399(8) C6 C5 1.410(8) C1 C2 1.390(8) C9 C10 1.363(9) C2 C3 1.424(9) C11 C10 1.375(8) C5 C4 1.409(8) C4 C3 1.393(9)
Table S3. Selected bond angles [ ] for [Ru]-3 C1 Ru1 C2 37.5(2) C7 N1 Ru1 120.3(2) C1 Ru1 C6 37.6(2) C7 N1 H1B 107.3 C2 Ru1 C6 67.9(2) Ru1 N1 H1B 107.3 C1 Ru1 C3 68.1(2) C7 N1 H1A 107.3 C2 Ru1 C3 38.3(2) Ru1 N1 H1A 107.3 C6 Ru1 C3 80.14(19) H1B N1 H1A 106.9 C1 Ru1 C5 68.2(2) C12 C7 C8 121.6(4) C2 Ru1 C5 80.7(2) C12 C7 N1 118.9(3) C6 Ru1 C5 37.8(2) C8 C7 N1 119.5(4) C3 Ru1 C5 67.6(2) C7 C8 C9 117.5(5) C1 Ru1 N1 96.31(16) C7 C8 C14 122.1(4) C2 Ru1 N1 120.62(19) C9 C8 C14 120.4(4) C6 Ru1 N1 96.91(15) C11 C12 C7 118.5(4) C3 Ru1 N1 158.2(2) C11 C12 C13 119.9(4) C5 Ru1 N1 122.12(17) C7 C12 C13 121.6(4) C1 Ru1 C4 80.5(2) C1 C6 C5 120.0(5) C2 Ru1 C4 68.3(2) C1 C6 Ru1 70.6(3) C6 Ru1 C4 68.0(2) C5 C6 Ru1 71.2(3) C3 Ru1 C4 37.2(2) C2 C1 C6 120.6(5) C5 Ru1 C4 37.6(2) C2 C1 Ru1 71.3(3) N1 Ru1 C4 159.2(2) C6 C1 Ru1 71.7(3) C1 Ru1 Cl1 154.10(16) C10 C9 C8 121.3(5) C2 Ru1 Cl1 157.08(18) C1 C2 C3 119.5(5) C6 Ru1 Cl1 116.66(17) C1 C2 Ru1 71.2(3) C3 Ru1 Cl1 118.82(19) C3 C2 Ru1 71.4(3) C5 Ru1 Cl1 90.76(15) C10 C11 C12 120.8(5) N1 Ru1 Cl1 81.93(9) C4 C5 C6 119.9(5) C4 Ru1 Cl1 91.95(18) C4 C5 Ru1 71.5(3) C1 Ru1 Cl2 116.56(16) C6 C5 Ru1 71.0(3) C2 Ru1 Cl2 90.31(15) C3 C4 C5 119.7(5) C6 Ru1 Cl2 154.12(17) C3 C4 Ru1 71.0(3) C3 Ru1 Cl2 91.29(15) C5 C4 Ru1 70.8(3) C5 Ru1 Cl2 155.53(16) C4 C3 C2 120.3(5) N1 Ru1 Cl2 82.03(8) C4 C3 Ru1 71.8(3) C4 Ru1 Cl2 117.92(17) C2 C3 Ru1 70.3(3) Cl1 Ru1 Cl2 88.91(4) C9 C10 C11 120.3(5)
Table S4. Effect of bases on the ruthenium catalyzed aqueous-aerobic homocoupling of phenylboronic acid a entry base temp / time conv. (%) b sel. (%) b ( o C/ h ) 2a 3a 1 K3PO4 70/4 9 13 87 2 KOH 70/4 10 14 86 3 Na3PO4 70/4 10 20 80 4 NaOH 70/4 88 34 66 5 NaHCO3 70/4 99 18 82 6 K2CO3 70/4 99 37 63 7 Na2CO3 70/4 99 47 53 8 without base 70/4 16 traces - c a Reaction conditions: 1a (1.0 mmol), base (2.0 mmol), cat. [Ru]-1 (2.5 mol%), water (5mL), b conversion of phenylboronic acid (1a) and selectivity for biphenyl (2a) and phenol (2b) respectively determined by 1 H NMR, c not detected.
Table S5. Effect of additive and reaction atmosphere on the ruthenium catalyzed aqueous-aerobic homocoupling of phenylboronic acid a entry base additive (equiv.) oxidant temp / time ( o C/ h) isolated yield of biphenyl (2a) (%) b 1 Na2CO3 Cu(OAc)2 air 70/4 67 (1.5 equiv.) 2 -- Cu(OAc)2 air 70/4 10 (1.5 equiv.) 3 Na2CO3 -- air 70/4 20 4 Na2CO3 Cu(OAc)2 air 70/4 43 (0.8 equiv.) 5 Na2CO3 Cu(OAc)2 air 70/4 30 (0.1 equiv.) 6 c Na2CO3 Cu(OAc)2 -- 70/4 no reaction (1.5 equiv.) 7 c Na2CO3 -- -- 70/4 no reaction a Reaction conditions: 1 (1.0 mmol), [Ru]-1 (5 mol%), water (4.7 ml) with added methanol (0.3 ml), base Na2CO3 (2.0 mmol), T = 70 ºC, b isolated yield of 2a in parentheses, c N2 atmosphere.
Table S6. Catalytic conversion of phenylboronic acid to biphenyl in the presence of different arene-ruthenium(ii) complexes a entry catalyst conv. (%) b sel. (%) b,c 2a 3a 1. [Ru]-1 99 80 (67) 20 2. [Ru]-2 99 57 (46) 43 3. [Ru]-3 99 53 (42) 47 4. [Ru]-4 99 60 (49) 40 5. [Ru]-5 99 47 (35) 53 a Reaction conditions: 1a (1.0 mmol), [Ru]-catalyst (5 mol%), Na2CO3 (2.0 mmol), Cu(OAc)2 (1.5 mmol), water (4.7 ml) with added methanol (0.3 ml), b conversion of phenylboronic acid (1a) and selectivity for biphenyl (2a) and phenol (2b) respectively determined by 1 H NMR, c isolated yield of purified product (2a) obtained from column chromatography is given in parentheses.
Table S7. Influence of catalyst on the catalytic conversion of different arylboronic acids to biaryls in the presence of different arene-ru(ii) complexes a entry R time biaryls conv./ sel. of 2a-2e/ sel. of 3a-3e (%) b,c (1a-1e) (h) (2a-2e) [Ru]-1 [Ru]-2 [Ru]-3 [Ru]-4 [Ru]-5 1 H 4 99/80/20 99/57/43 99/53/47 99/60/40 99/47/53 (1a) (2a) (67) (46) (42) (49) (35) 2 p-me 10 99/84/16 99/66/34 99/54/46 99/75/25 99/70/30 (1b) (2b) (55) (44) (36) (49) (46) 3 p-ome 10 99/99 99/90/10 99/79/21 99/91/9 99/88/12 (1c) (2c) (68) (66) (57) (66) (60) 4 p-cl 12 99/92/8 99/80/20 99/64/36 99/76/24 99/54/46 (1d) (2d) (54) (47) (37) (43) (25) 5 p-f 8 99/83/17 99/80/20 99/72/28 99/74/26 99/65/35 (1e) (2e) (36) (33) (30) (31) (27) a Reaction conditions: 1a-1e (1.0 mmol), Na2CO3 (2.0 mmol), [Ru]-catalyst (5 mol%), additive Cu(OAc)2 (1.5 mmol), water (4.7 ml) with added methanol (0.3 ml), T = 70 ºC, b conversion of arylboronic acid (1a-1e) and selectivity for 2a-2e and 3a-3e respectively, determined by 1 H NMR, c isolated yields of purified products (2a-2e) obtained from column chromatography are given in parentheses.
Table S8. Role of aniline ligand in the ruthenium catalyzed homocoupling reactions of phenylboronic acid a entry catalyst base conv./ sel. of 2a / sel. of 3a (%) b 1 [(η 6 benzene)rucl2]2 (1.25 mol%) Na2CO3 99/35/65 2 [(η 6 benzene)rucl2]2 (1.25 mol%) + aniline Na2CO3 99/42/58 (2.5 mol%) 3 [(η 6 benzene)ru(aniline)cl2] ([Ru]-1) (2.5 Na2CO3 99/63/37 mol%) 4 [(η 6 benzene)ru(aniline)cl2] ([Ru]-1) (2.5 no base 16/99/0 mol%) 5 without catalyst Na2CO3 no reaction 6 [(η 6 benzene)rucl2]2 (1.25 mol%) + Na2CO3 99/25/75 p-methylaniline (2.5 mol%) 7 [(η 6 benzene)rucl2]2 (1.25 mol%) Na2CO3 99/28/72 + p-chloroaniline (2.5 mol%) 8 [(η 6 benzene)ru(pph3)cl2] (2.5 mol%) Na2CO3 3/trace/0 a Reaction conditions: 1a (1.0 mmol), Na2CO3 (2.0 mmol), [Ru]-catalyst, water (4.7 ml) withadded methanol (0.3 ml), b conversion of phenylboronic acid (1a) and selectivity for biphenyl (2a) and phenol (3a) respectively determined by 1 H NMR.
Figure S1. Crystal structure of the complex [Ru-4]. Ellipsoids are set at 30% probability. All hydrogen atoms, except those on nitrogen, are omitted for clarity.
Figure S2. GC-MS spectra of the competitive reaction of 4-methylphenylboronic acid (1b) with 4-methoxyphenylboronic acid (1c).
Figure S3. GC-MS spectra of the competitive reaction of 4-methylphenylboronic acid (1b) with 4-chlorophenylboronic acid (1d).
Figure S4. GC-MS spectra of the competitive reaction of 4-methylphenylboronic acid (1b) with 4-trifluoromethylphenylboronic acid (1g).
Weight (%) 100 90 80 [Ru]-1 [Ru]-2 [Ru]-3 [Ru]-4 [Ru]-5 70 60 50 40 30 20 200 300 400 Temperature ( C) Figure S5. Thermal gravimetric analysis (TGA) graph of complexes [Ru]-1 to [Ru]-5.
7.39 5.00 7.47 7.41 7.43 7.45 7.26 5.36 7.39 7.41 7.43 7.44 4.97 7.26 5.35 7.38 7.40 7.43 7.44 4.87 7.26 5.35 Cl Cl Ru NH 2 b a a b t = 24 h 5.20 6.00 1.80 a b t = 12 h 5.02 6.00 1.98 a Chloroform-d b t = 4 h 5.00 6.60 2.13 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 Figure S6. 1 H NMR spectra for the thermal stability of [Ru]-1 catalyst at 70 C.
(a) Observed m/z Simulated m/z (b) Observed m/z Simulated m/z Figure S7. Observed and simulated mass patterns of aryl-ru intermediate species of the [Ru]-catalyzed homocoupling reaction of (a) p-methylphenylboronic acid (1b), and (b) p-chlorophenylboronic acid (1d).
(a) (b) Observed m/z Simulated m/z Figure S8. Observed and simulated mass patterns of di(σ aryl)-ru species, key intermediates in the catalytic homocoupling of arylboronic acids, with the [Ru]-2 catalyst, obtained in the presence of 2.0 equivalent excess of (a) p- methylphenylboronic acid (1b), and (b) p-chlorophenylboronic acid (1d) in acetonitrile.
Observed m/z Simulated m/z Figure S9. Observed and simulated mass patterns of aryl-ru intermediate species of the transmetallation step of the homocoupling reaction of phenylboronic acid (1a) and p-methylphenylboronic acid (1b) with complex [Ru]-1 in water.
335.04 Observed m/z Simulated m/z Figure S10. Observed and simulated mass patterns of aryl-ru intermediate species of the transmetallation step of the homocoupling reaction of phenylboronic acid (1a) and p-methylphenylboronic acid (1b) with complex [Ru]-4 in water with observed and simulated mass patterns.
335.04 Observed m/z Simulated m/z Figure S11. Observed and simulated mass patterns of aryl-ru intermediate species of the transmetallation step of homocoupling reaction of phenylboronic acid (1a) and p-methylphenylboronic acid (1b) with complex [Ru]-5 in water.
ppm Figure S12. 19 F NMR for the 4,4 -difluorobiphenyl (2e) and of 4-fluorophenol (3e) species, along with the aryl-ru species, generated during the homocoupling reaction of p-fluorophenylboronic acid (1e) in the presence of [Ru]-2 catalyst.
Figure S13. 19 F NMR for the 4,4 -trifluoromethylbiphenyl (2g) and of 4- trifluoromethylphenyl species, along with the aryl-ru species, generated during the homocoupling reaction of p-trifluoromethylphenylboronic acid (1g) in the presence of [Ru]-2 catalyst.
Scheme S1. Possible role of aerial O2 and Cu(OAc)2 additives in the ruthenium catalyzed homocoupling of arylboronic acids. Scheme S2. Proposed mechanism for the ruthenium catalyzed homocoupling of arylboronic acid as established by ESI-MS, 1 HNMR and 19 F NMR spectral studies.
143.82 131.57 127.56 125.98 120.22 17.79 83.11 77.36 77.05 76.73 7.19 7.17 4.79 7.36 7.30 7.28 7.26 2.45 7.36 7.34 7.30 7.28 7.19 7.17 7.26 5.31 NMR Spectra of arene-ru(ii) complexes 1 H and 13 C NMR spectra of complex [Ru]-2 3.82 1.00 7.50 7.25 7.00 Cl Cl Ru NH 2 3.82 6.04 1.77 3.26 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 Cl Cl Ru NH 2 144 136 128 120 112 104 96 88 80 72 64 56 48 40 32 24 16 8
120.52 115.78 17.77 127.71 30.68 87.64 40.13 39.92 39.71 39.50 39.08 6.40 6.38 6.36 4.44 6.76 2.49 5.95 3.33 2.05 1 H and 13 C NMR spectra of complex [Ru]-3 Cl Cl Ru NH 2 DMSO-d6 2.00 1.08 5.91 2.06 6.33 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 DMSO-d6 Cl Cl Ru NH 2 128 120 112 104 96 88 80 72 64 56 48 40 32 24 16
143.10 135.46 20.91 130.19 119.90 83.14 76.69 77.00 77.32 7.35 7.33 7.19 7.17 4.95 2.36 7.35 7.33 7.26 7.19 7.17 5.35 1 H and 13 C NMR spectra of complex [Ru]-4 2.28 2.19 Cl Cl Ru NH 2 7.50 7.25 7.00 Chloroform-d 2.28 6.00 2.03 3.41 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 Chloroform-d Cl Cl Ru NH 2 144 136 128 120 112 104 96 88 80 72 64 56 48 40 32 24
1 H NMR spectra of complex [Ru]-5 Chloroform-d Cl Cl Ru NH 2 Cl 7.40 7.38 4.83 7.40 7.38 7.36 7.34 7.32 7.26 5.38 7.26 Chloroform-d 4.39 7.45 7.40 7.35 7.30 7.25 7.20 7.15 4.39 6.00 1.56 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0
Spectral data of biaryl products obtained from ruthenium catalyzed homocoupling of arylboronic acids Biphenyl (2a) 1 H NMR (400 MHz, CDCl3): δ (ppm) = 7.61(d, 4H, J = 8 Hz), 7.45 (t, 4H, J = 8 Hz), 7.36 (t, 2H, J = 8 Hz). 13 C NMR (100 MHz, CDCl3): δ (ppm) = 141.23, 128.73, 127.23, 127.15. 4,4'-Dimethylbiphenyl(2b) 1 H NMR (400 MHz, CDCl3): δ (ppm) = 7.48 (d, 4H, J = 8 Hz), 7.24 (d, 4H, J = 8 Hz), 2.39 (s, 6H). 13 C NMR (100 MHz, CDCl3): δ (ppm) = 138.27, 136.67, 129.41, 126.79, 21.05. 4,4'-Dimethoxybiphenyl (2c) 1 H NMR (400 MHz, CDCl3): δ (ppm) = 7.48 (d, 4H, J = 8 Hz), 6.96 (d, 4H, J = 8 Hz), 3.85 (s, 6H). 13 C NMR (100 MHz, CDCl3): δ (ppm) = 158.69, 133.49, 127.73, 114.18, 55.32. 4,4'-Dichlorobiphenyl(2d) 1 H NMR (400 MHz, CDCl3): δ (ppm) = 7.47 (d, 4H, J = 8 Hz), 7.40 (d, 4H, J = 8 Hz). 13 C NMR (100 MHz, CDCl3): δ (ppm) = 138.42, 133.74, 129.03, 128.21.
4,4'-Difluorobiphenyl (2e) 1 H NMR (400 MHz, CDCl3): δ (ppm) = 7.51-7.47 (m, 4H), 7.12 (d, 4H, J = 8 Hz). 13 C NMR (100 MHz, CDCl3): δ (ppm) = 162.42 (J = 45 Hz), 136.39 (J = 3 Hz), 128.5 (J = 8 Hz), 115.67 (J = 21 Hz). 19 F NMR (376.5 MHz, CDCl3): δ (ppm) = 123.430. 4,4 -Bis(trifluoromethoxy)biphenyl (2f) 1 H NMR (400 MHz, CDCl3): δ (ppm) = 7.55 (d, 4H, J = 8 Hz), 7.30 (d, 4H, J = 8 Hz). 19 F NMR (376.5 MHz, CDCl3): δ (ppm) = 57.95. 4,4 -Bis(trifluoromethyl)biphenyl (2g) 1 H NMR (400 MHz, CDCl3): δ (ppm) = 7.75-7.69 (m, 8H). 19 F NMR (376.5 MHz, CDCl3): δ (ppm) = 62.59.
141.23 127.15 128.73 77.00 7.33 7.35 7.43 7.62 7.45 7.37 7.36 7.34 7.43 7.62 7.60 7.60 1 H, 13 C and 19 F NMR Spectra of homocoupled products 7.47 7.45 Chloroform-d 2a 4.00 4.05 2.02 7.6 7.5 7.4 7.3 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0-0.5 Chloroform-d 2a 136 128 120 112 104 96 88 80 72 64 56 48 40 32 24 16
138.27 136.67 21.05 77.31 77.00 76.68 129.41 126.79 0.00 7.39 7.41 7.14 7.16 7.39 7.41 7.14 7.16 2.31 2.31 Me Me 2b 4.00 4.04 7.25 7.00 6.25 2.40 2.35 2.30 2.25 2.20 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 Me Me Chloroform-d 2b 136 128 120 112 104 96 88 80 72 64 56 48 40 32 24 16
29.69 158.69 133.49 55.32 114.16 127.73 76.69 77.00 77.32 0.08 7.49 7.47 6.98 6.95 7.49 7.47 6.98 6.95 3.85 3.85 MeO OMe 2c Chloroform-d 4.00 7.50 7.25 7.00 4.16 6.09 4.0 3.9 3.8 Chloroform-d 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 Chloroform-d MeO OMe 2c 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10
7.48 7.46 138.42 133.74 129.03 128.21 77.31 77.00 76.68 7.26 7.39 7.48 7.26 7.39 7.46 7.41 7.41 Cl Cl 4.13 4.00 2d 7.50 7.25 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 Chloroform-d Cl Cl 2d 136 128 120 112 104 96 88 80 72 64 56 48
163.65 161.20 136.38 136.41 128.53 128.61 115.57 115.78 0.07 7.14 7.10 7.47 7.49 7.49 7.51 7.26 7.47 7.49 7.49 7.51 7.14 7.10 7.12 7.12 Chloroform-d Chloroform-d F F 2e 4.00 3.98 7.6 7.5 7.4 7.3 7.2 7.1 7.0 6.9 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 Chloroform-d F F 2e 165 160 155 150 145 140 135 130 125 120 115 110 105 100 95 90 85 80 75
-57.98-57.95 7.31 7.26 7.56 7.54 7.31 7.29 7.26 7.56 7.54 F 3 CO OCF 3 2f 4.10 4.00 7.7 7.6 7.5 7.4 7.3 7.2 7.1 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 F 3 CO OCF 3 2f -52-53 -54-55 -56-57 -58-59 -60 19 F NMR of compound 2f
-62.59 7.68 7.62 7.75 7.69 7.66 7.64 7.71 7.73 F 3 C CF 3 2g 8.00 7.9 7.8 7.7 7.6 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 F 3 C CF 3 2g -59.5-60.0-60.5-61.0-61.5-62.0-62.5-63.0-63.5-64.0-64.5-65.0-65.5-66.0 19 F NMR of compound 2g
GC-MS spectra of the biphenyl (2a).
GC-MS spectra of the 4,4 dimethylbiphenyl (2b).
GC-MS spectra of the 4,4 - dimethoxylbiphenyl (2c).
GC-MS spectra of the 4,4 -dichlorobiphenyl (2d).
GC-MS spectra of the 4,4 -difluorobiphenyl (2e).
REFERENCES S1 Rao, B.; Zhang, W.; Hua, L.; Luo, M. Green Chem. 2012, 14, 3436-3440. S2 Xiong, Q.; Fu, Z.; Li, Z.; Cai, H. Synlett. 2015, 26, 975-979. S3 Kapdi, A. R.; Dhangar, G.; Serrano, J. L.; Pѐrez, J.; García L.; Fairlamb, I. J. S. Chem. Commun. 2014, 50, 9859-9861. S4 González-Arellano, C.; Corma, A.; Iglesias, M.; Sánchez, F. Chem. Commun. 2005, 1990-1992. S5 Vogler, T.; Studer, A. Adv. Synth. Catal. 2008, 350, 1963-1967 S6 Lin, C.-N.; Huang, C.-Y.; Yu, C.-C.; Chen, Y.-M.; Ke, W.-M.; Wang, G.-J.; Lee, G.- A.; Shieh, M.; Dalton Trans. 2015, 44, 16675-16679. S7 Puthiaraj, P.; Suresh, P.; Pitchumani, K. Green Chem. 2014, 16, 2865-2875. S8 Kaboudin, B.; Mostafalu, R.; Yokomatsu, T. Green Chem. 2013, 15, 2266-2274. S9 Kaboudin, B.; Abedi, Y.; Yokomatsu, T. Eur. J. Org. Chem. 2011, 6656-6662.