Supporting Information. A Hydroquinone Based Palladium Catalyst for Room Temperature Nitro reduction in water

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1 Electronic Supplementary Material (ESI) for RSC Advances. This journal is The Royal Society of Chemistry 2014 Supporting Information For A Hydroquinone Based Palladium Catalyst for Room Temperature itro reduction in water Alok Kumar, Kallol Purkait, Suman Kr. Dey, Amrita Sarkar and Arindam Mukherjee* a Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur , India, a.mukherjee@iiserkol.ac.in Both the authors contributed equally to this work 1

2 Contents Experimental Section... 4 Materials and instrumentation... 4 Synthesis of 3,5-dimethylpyrazole... 4 Synthesis of ligand H 2 L... 4 Synthesis of complex X-ray crystallography... 5 Table S1. Selected crystallographic parameters of 1.2H Table S2. Selected bond lengths (Å) and angles ( ) for 1.2H General catalytic nitro reduction for aryl nitro substrates used for optimization reactions... 7 ptimization of complex 1 catalysed reduction of nitro arene reaction Table S3. Screening of solvent for aryl nitro reduction catalyzed by 1. a... 7 Table S4. Screening of temperature for aryl nitro reduction of itrobenzene catalyzed by 1. a... 7 Table S5. Screening of catalyst loading for aryl nitro reduction of itrobenzene catalyzed by 1. a 8 Table S6. Catalytic ability of complex 1 over few other common Pd-compounds. a... 8 Representative procedure of catalytic reduction of nitroarenes substrates... 8 General catalytic Suzuki-Miyaura cross coupling reaction for aryl halide substrates with phenyl boronic acid used for optimization reactions... 8 ptimization of complex 1 catalysed Suzuki-Miyaura cross coupling reaction... 9 Table S7. ptimization of solvent for Suzuki-Miyaura cross coupling reaction of 4-bromo anisole with phenylboronic acid catalyzed by 1. a... 9 Table S8. ptimization of base for Suzuki-Miyaura cross coupling reaction of 4-bromo anisole with phenylboronic acid catalyzed by 1. a... 9 Table S9. Screening of catalyst loading for Suzuki-Miyaura cross coupling reaction of 4- bromoanisole with phenylboronic acid catalyzed by 1. a Table S10. Screening of temperature for Suzuki-Miyaura cross coupling reaction of 4- bromoanisole with phenylboronic acid catalyzed by 1. a Scheme S1. Proposed catalytic cycle for Suzuki-Miyaura cross coupling reaction by complex 1 in presence of base. The mechanistic pathway is similar to that known in literature Table S11. Suzuki-Miyaura cross coupling reaction of aryl halides with Phenylboronic acid. a General procedure for Syntheses of biaryl amines from nitro substituted aryl halides and phenylboronic acid in one pot using catalyst Scheme S2. Proposed dehalogenation and nitroarene reduction mechanism by catalyst 1 using 1-bromo-4-nitrobenzene as a model substrate. The complex is dipositively charged when the palladium is +2 oxidation state Figure S1. 1 H MR spectrum of the reaction between iodobenzene (0.018mmol) and abh 4 (0.018 mmol) in presence of catalyst 1 (0.003 mmol) in methanol-d 4 at 25 C. More than 90% conversion 2

3 has occurred within 4-5 min since the spectra shows presence of only ca. 6% substrate (iodobenzene) Figure S2. 1 H MR spectrum of reaction mixture of iodobenzene (0.018mmol) and abh 4 (0.018 mmol) in presence of 1 (0.003 mmol, to have sufficient concentration in 1 H MR). Solvent is methanol-d 4, spectrum recorded at 25 C and only the relevant region was scanned for better signal to noise ratio Figure S3. 1 H MR of 0.03 mmol of 4-nitrobenzonitrile, 0.24 mmol abh 4, 0.25 mol% catalyst 1 in D 2. 1,4-dioxane was used for reference H and 13 C MR data of Suzuki-Miyaura product methoxybiphenyl methylbiphenyl acetylbiphenyl nitrobiphenyl cyanobiphenyl phenylpyridine nitrobiphenyl H and 13 C MR data of nitro reduction product Aniline aminophenol cyanoaniline (pyridin-4-ylmethyl)aniline chloro-1,2-diaminobenzene H and 13 C MR data of tandem type reaction product aminobiphenyl aminobiphenyl References

4 Experimental Section Materials and instrumentation Palladium chloride was purchased from Precious metal online, Australia. All the other chemicals for catalysis were purchased from sigma-aldrich, Spectrochem and SRL (India) and used without any further purification. The solvents were dried or distilled prior to use. 1 HPLC grade water and ethanol from spectrochem, India were used for catalysis. For the characterization of the ligand, metal complexes and all products of the catalytic reaction we used 400 MHz JEL MR spectrophotometer or 500 MHz BRUKER spectrophotometer. The chemical shifts are reported in parts per million (ppm). All MR data were collected at room temperature (25 C). Melting points and decomposition temperatures of the compounds were measured in triplicate with one end sealed capillaries using SECR India melting point apparatus and the uncorrected values are reported. UV-Visible measurements were done using Perkin Elmer lambda 35 spectrophotometer. FT-IR spectra were recorded using Perkin-Elmer SPECTRUM RX I spectrometer in KBr pellets. Perkin -Elmer 2400 series II CHS/ analyzer was used for elemental analysis. Electro-spray ionization mass spectra were recorded by +ve mode electrospray ionization, using a Q-Tof micro (Waters) mass spectrometer. Single crystal X-ray data was collected on an Agilent Technologies Supernova (xford Diffraction) diffractometer. The recrystallization yields of isolated ligand and metal complexes, isolated products of catalysis reaction after column chromatography are reported. All the compounds, ligand and metal complex were dried in vacuum and stored in desiccators under dark. Synthesis of 3,5-dimethylpyrazole The compound was synthesized by dropwise addition of hydrazine hydrate on acetylacetone at 0 C and continues the stirring for half an hour. A white coloured product is immediately separated out from the solution. After 0.5 h white solid was collected by filtration and purified by washing with petroleum benzene. Yield (90%), 1 H MR (400 MHz, CDCl 3, 25 C): δ (br. s, 1H, H), 5.81 (s, 1H, ArH), 2.27 (s, 6H, CH 3 ). 13 C MR (100 MHz, CDCl 3, 25 C): δ , , Synthesis of ligand H2L Compound H 2 L was synthesized by refluxing p-benzoquinone with 3,5-dimethylpyrazole in 1,4- dioxane under nitrogen atmosphere as in literature procedure. 2 The product was further purified by silica gel (60-120mesh) column chromatography using dichloromethane and ethyl acetate 7:3 mixtures. Yield (25%), Mp C. 1 H MR (500 MHz, CDCl 3, 25 C): δ 7.25 (s, 2H, H), 7.04 (s, 2H, ArH), 5.89 (s, 2H, ArH), 2.28 (s, 6H, 2CH 3 ), 1.67 (s, 6H, 2CH 3 ). 13 C MR (125 MHz, CDCl 3, 25 C): δ , , , , , , 13.31, ESI-MS (Methanol) m/z (calc.): (299.15) [C 16 H ] Elemental analysis: Anal. Calcd. for C 16 H : C, 64.41; H, 4

5 6.08;, Found: C, 64.36; H, 6.11;, UV-vis λ max /nm (ε/dm 3 mol 1 cm 1 ) in CH 3 C: 306 (4510), 222 (10025), 206 (9727). FT-IR (KBr) (ν max /cm 1 ): 2933, 2624, 1557, 1499, Synthesis of complex g (1.0 mmol) of H 2 L with 0.259g (1.0 mmol) of Pd II (MeC) 2 Cl 2 were dissolved in acetonitrile and heated to reflux under dark. After 16h the reaction mixture was cooled to room temperature and concentrated on a rotary evaporator to get precipitation of the metal complex. The precipitation was collected by filtration and washed with diethyl ether, which was further purified by crystallisation from acetonitrile and ethyl acetate 5:2 mixture solution by slow evaporation method. Yield (95%), Mp. (decomp.) >300 C. 1 H MR (500 MHz, DMS-d6, 25 C): δ (s, 2H, H), 7.32 (s, 2H, ArH), 6.13 (s, 2H, ArH), 2.52 (s, 6H, 2CH 3 ), 2.06 (s, 6H, 2CH 3 ) (Figure S4). 13 C MR (125 MHz, DMS-d6, 25 C): δ , , , , , , 14.06, (Figure S5), ESI- MS (Methanol) m/z (calc.): (403.04) [C 16 H Pd + ], Elemental analysis: Anal. calcd. for C 16 H 18 Cl Pd: C, 40.4; H, 3.18;, Found: C 40.7 H, 3.35,, UV-vis λ max /nm (ε/dm 3 mol 1 cm 1 ) in CH 3 C: 308 (9227). FT-IR (KBr) (ν max /cm 1 ): 3360, 2362, 1554, 1507, X-ray crystallography A good quality brick red coloured single crystal was obtained from acetonitrile solution using the method of slow evaporation. Single crystal X-ray diffraction study was carried out on the Agilent Technologies Supernova diffractometer and measured at 300 K using Mo-Kα radiation ( Å). An empirical multi-scan absorption correction was performed using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm. The integral values (from the instrument) were refined in apex2 software where all non-hydrogen atoms were refined anisotropically by full matrix least-squares on F 2 to get the structure. The hydrogen atoms were calculated and fixed using SHELXL-97 after hybridization of all non hydrogen atoms. 3 Selected crystallographic parameters are enlisted in Table S1. The crystallographic data of 1 has been deposited at the Cambridge Crystallographic Data Centre as supplementary publication CCDC These data can be obtained free of charge from the Cambridge Crystallographic Data Centre via 5

6 Table S1. Selected crystallographic parameters of 1.2H 2 1.2H 2 Empirical formula C 16 H 20 Cl Pd Formula weight Temperature (K) 100(2) Wavelength(Å) Crystal system rthorhombic space group Cmc2(1) a (Å) (10) b (Å) (3) c (Å) (4) (deg.) 90 (deg.) 90 γ (deg.) 90 Volume (Å 3 ) (15) Z, Calculated density (Mg/m 3 ) 4, F(000) 1120 Reflections collected / unique 2816 / 1921 [R(int) = ] Max. and min. transmission and Goodness-of-fit on F Final R indices [I>2σ(I)] R1 = , wr2 = R indices (all data) R1 = , wr2 = Table S2. Selected bond lengths (Å) and angles ( ) for 1.2H 2 Pd(1)-(1) (1)-Pd(1)-(1A) a 85.5 Pd(1)-Cl(1) (1)-Pd(1)-Cl(1) Cl(1)-Pd(1)-Cl(1A) a a A = -x+1, y, z 6

7 General catalytic nitro reduction for aryl nitro substrates used for optimization reactions itro arene (1.0mmol), abh 4 (4.0 mmol) were dissolved in10ml of ethanol followed by the addition of 4.7 mg (1.0 mol %) of catalyst. After that the reaction mixture was refluxed according to the reflux temperature of solvent under dark and completion was monitored by silica gel thin layer chromatography. The solvent was evaporated under reduced pressure and re-dissolved in ethyl acetate and washed two times with water. Further the product was purified by silica column chromatography using 20% dichloromethane in petroleum benzene. ptimization of complex 1 catalysed reduction of nitro arene reaction. Table S3. Screening of solvent for aryl nitro reduction catalyzed by 1. a 2 Pd-catalyst H 2 abh 4, Solvent reflux Entry Solvent Isolated Yield (%) b Time (min) 1 Ethanol > H 2 >99 15 a Reaction conditions: 1.0 mmol nitrobenzene, 4.0 mmol sodium borohydride, 4.7 mg (1 mol %) catalyst, solvent, reflux. b Isolated yields were reported after performed column chromatography. Table S4. Screening of temperature for aryl nitro reduction of itrobenzene catalyzed by 1. a 2 Pd-catalyst H 2 abh 4, water, T o C Entry Temperature(T o C) Isolated Yield (%) b Time (min) 1 85 > > >98 20 a Reaction conditions: 1.0 mmol nitrobenzene, 4.0 mmol sodium borohydride, water, 4.7 mg (1 mol %) catalyst, T C. b Isolated yield were reported after column chromatography. 7

8 Table S5. Screening of catalyst loading for aryl nitro reduction of itrobenzene catalyzed by 1. a 2 H 2 Pd-catalyst abh 4, water, 27 o C Entry Catalyst Loading (mol %) Isolated Yield (%) b Time (min) > > >99 25 a Reaction conditions: 1.0 mmol nitrobenzene, 4.0 mmol Sodium borohydride, catalyst 1, water, 27 C. b Isolated yields were reported after column chromatography. Table S6. Catalytic ability of complex 1 over few other common Pd-compounds. a 2 Pd-catalyst H 2 C abh 4, ethanol, 27 o C C Entry Catalyst Catalyst loading (mol % ) Isolated Yield (%) [b] Time (h) b 1 Pd(Ac) < PdCl < Pd(MeC) 2 Cl < > a Reaction conditions: 1.0 mmol nitroarene, 4.0 mmol Sodium borohydride, catalyst 1, ethanol, 27 C. b Isolated yields were reported after column chromatography. Representative procedure of catalytic reduction of nitroarenes substrates 1.0 mmol of nitroarene dissolved in 10ml of water followed by g (4.0 mmol) abh 4 and 1.2 mg (0.25 mol %) 1, were added to the reaction mixture at 27 C and stirred vigorously. The completion of the reaction was monitored by silica thin layer chromatography. After completion, the reaction mixture was dried under reduced pressure and further purified by short silica column chromatography ( mesh) using proper ratio of dichloromethane in petroleum benzene as eluent. The pure product was stored in desiccator under dark. General catalytic Suzuki-Miyaura cross coupling reaction for aryl halide substrates with phenyl boronic acid used for optimization reactions Aryl halide (1.0 mmol), phenylboronic acid (1.5 mmol), base (3.0 mmol) and 2.3 mg (0.5 mol %) of catalyst (complex 1) were kept in a single neck round bottom flask followed by 10ml solvent was added to it. ow the reaction was performed at reflux temperature. After completion of the reaction, 8

9 the reaction mixture was dried under reduced pressure. Dissolve the reaction mixture in dichloromethane and washed two times with water. The organic layer was dried over a 2 S 4 and purified through a short column chromatography (silica gel mesh) using the appropriate ratio of petroleum ether and dichloromethane to get pure biaryl. ptimization of complex 1 catalysed Suzuki-Miyaura cross coupling reaction Table S7. ptimization of solvent for Suzuki-Miyaura cross coupling reaction of 4-bromo anisole with phenylboronic acid catalyzed by 1. a Br + H B H Pd-cat (0.5mol%) K 2 C 3, Solvent, reflux Entry Solvent Isolated Yield (%) b Time (h) 1 H 2 < Ethanol > Dichloromethane Toluene ,4-Dioxane Acetonitrile < a Reaction conditions: 1.0 mmol 4-bromoanisole, 1.5 mmol phenylboronic acid, 0.5 mol% catalyst 1, 3 mmol K 2 C 3, solvent, reflux. b Isolated yields were reported after column chromatography Table S8. ptimization of base for Suzuki-Miyaura cross coupling reaction of 4-bromo anisole with phenylboronic acid catalyzed by 1. a Br + H B H Pd-cat (0.5 mol%) base, ethanol, reflux Entry Base Isolated Yield (%) b Time (h) 1 K 2 C 3 > Cs 2 C ame Et KH a Reaction conditions: 1 mmol 4-bromoanisole, 1.5 mmol phenylboronic acid, 0.5 mol% catalyst 1, 3 mmol base, ethanol, reflux. b Isolated yields were reported after column chromatography 9

10 Table S9. Screening of catalyst loading for Suzuki-Miyaura cross coupling reaction of 4- bromoanisole with phenylboronic acid catalyzed by 1. a Entry Br + H B H Catalyst Loading (mol %) Pd-cat K 2 C 3, ethanol, reflux Isolated Yield (%) b Time (h) a > > Reaction conditions: 1 mmol 4-bromoanisole, 1.5 mmol phenylboronic acid, catalyst 1, 3 mmol K 2 C 3, ethanol, reflux. b Isolated yields were reported after performed column chromatography. Table S10. Screening of temperature for Suzuki-Miyaura cross coupling reaction of 4- bromoanisole with phenylboronic acid catalyzed by 1. a Br + H B H Pd-cat (0.25 mol %) K 2 C 3, T o C Entry Temperature (T C) Isolated Yield (%) b Time (h) 1 80 > > a Reaction conditions: 1.0 mmol 4-bromoanisole, 1.5 mmol phenylboronic acid,0.25 mol% catalyst 1, 3.0 mmol K 2 C 3, ethanol. b Isolated yields were reported after column chromatography. Representative procedure for Suzuki-Miyaura cross coupling reaction Aryl halide (1.0 mmol), phenylboronic acid (1.5 mmol), potassium carbonate (3.0 mmol) and 1.2 mg (0.25 mol %) of catalyst (complex 1) were kept in a single neck round bottom flask followed by which 10ml ethanol was added to it. ow the reaction was performed at 27 C. After completion of the reaction, the reaction mixture was dried under reduced pressure and re-dissolved in dichloromethane then washed for two times with water. The organic layer was dried over a 2 S 4 and purified through a short column chromatography (silica gel mesh) using the appropriate ratio of petroleum ether and dichloromethane to get the pure biaryl. 10

11 H H Cl II Pd Cl Ar' Reductive Elimination Pd 0 X xidative Addition Pd II Ar' II Pd X B(C 3 ) 2 (H) 2 H Ar' B H Transmetallation Pd II C 2 KCl K 2 C 3 Scheme S1. Proposed catalytic cycle for Suzuki-Miyaura cross coupling reaction by complex 1 in presence of base. The mechanistic pathway is similar to that known in literature. 4 Table S11. Suzuki-Miyaura cross coupling reaction of aryl halides with Phenylboronic acid. a ArX + H B H 1(0.25mol%) Ar Entry Substrate (ArX) Product Isolated Yield b (%) Time (h) 1 Br H 3 CC H 3 CC 2 Br H 3 C H 3 C

12 Cl C C Cl H 3 C H 3 C Br H 3 C I > H 3 C 7 H 3 C I > H 3 C I 8 > Br C Br C a Reaction conditions: 1.0 mmol aryl halide, 1.5 mmol phenylboronic acid, 0.25 mol% catalyst 1, 3.0 mmol K 2 C 3, ethanol, 27 C. b Isolated yields were reported after column chromatography. c 2 mol% catalyst 1, 3.0 mmol K 2 C 3, ethanol, 80 C General procedure for Syntheses of biaryl amines from nitro substituted aryl halides and phenylboronic acid in one pot using catalyst mmol of nitro substituted aryl halide, 1.5 mmol phenylboronic acid, 3.0 mmol K 2 C 3 were taken in a single neck round bottom flask followed by addition of 15 ml of ethanol and 1.2 mg (0.25 mol %) of catalyst at room temperature. The completion of the reaction was monitored by silica gel thin layer chromatography. After that immediately g (4.0 mmol) abh 4 was added and stirred for another 1 h under dark. The solvent of the reaction mixture was evaporated under reduced pressure and the residues redissolved in dichloromethane, washed two times with water. Finally the product was purified by short silica ( mesh) column chromatography using dichloromethane and petroleum benzene mixture. The pure products were isolated and stored in desiccator under dark. 12

13 H H Pd II Cl Cl 2 2 Br Br Pd II Pd 0 2 H abh 4 Pd II 2 2H +, 2e - Pd 0 H H Pd II Pd II abh 4 H 2 + H 2 + H 2 abh 4 H H Pd II Pd II 2H +, 2e - Pd 0 2H +, 2e - HH Pd 0 H Pd II H Pd II abh 4 Scheme S2. Proposed dehalogenation and nitroarene reduction mechanism by catalyst 1 using 1-bromo-4-nitrobenzene as a model substrate. The complex is dipositively charged when the palladium is +2 oxidation state. 13

14 Figure S1. 1 H MR spectrum of the reaction between iodobenzene (0.018mmol) and abh4 (0.018 mmol) in presence of catalyst 1 (0.003 mmol) in methanol-d4 at 25 C. More than 90% conversion has occurred within 4-5 min since the spectra shows presence of only ca. 6% substrate (iodobenzene). Figure S2. 1 H MR spectrum of reaction mixture of iodobenzene (0.018mmol) and abh4 (0.018 mmol) in presence of 1 (0.003 mmol, to have sufficient concentration in 1 H MR). Solvent is methanol-d4, spectrum recorded at 25 C and only the relevant region was scanned for better signal to noise ratio. 14

15 Figure S3. 1 H MR of 0.03 mmol of 4-nitrobenzonitrile, 0.24 mmol abh 4, 0.25 mol% catalyst 1 in D 2. 1,4-dioxane was used for reference. 1H and 13 C MR data of Suzuki-Miyaura product 4-methoxybiphenyl. 1 H MR (CDCl 3, 400 MHz, 25 C) 7.55 (m, 4H, ArH), 7.43 (m, 2H, ArH), 7.31 (m, 1H, ArH), 6.99 (m, 2H, ArH), 3.86 (s, 3H, CH 3 ) (Figure S6). 13 C MR (CDCl 3, 100 MHz, 25 C) , , , , , , , , (Figure S7). 4-methylbiphenyl. 1 H MR (CDCl 3, 400 MHz, 25 C) 7.60 (d, J = 9.44 Hz, 2H, ArH), 7.52 (d, J = 7.6 Hz, 2H, ArH), 7.4 (m, 2H, ArH), 7.35 (m, 1H, ArH), 7.27 (m, 2H, ArH), 2.43 (s, 3H, CH 3 ) (Figure S8). 13 C MR (CDCl 3, 100 MHz, 25 C) , , , , , , (Figure S9). 4-acetylbiphenyl. 1 H MR (CDCl 3, 400 MHz, 25 C) 8.02 (d, J = 8.4 Hz, 2H, ArH), 7.68 (d, J = 8.4 Hz, 2H, ArH), 7.61 (m, 2H, ArH), 7.47 (m, 2H, ArH), 7.42 (m, 1H, ArH), 2.64 (s, 3H, CH 3 ) (Figure S10). 13 C MR (CDCl 3, 100 MHz, 25 C) , , , , , , , , , (Figure S11). 4-nitrobiphenyl. 1 H MR (CDCl 3, 400 MHz, 25 C) 8.28 (d, J = 9.16 Hz, 2H, ArH), 7.72 (d, J = 8.4 Hz, 2H, ArH), 7.62 (m, 2H, ArH), 7.46 (m, 3H, ArH) (Figure S12). 13 C MR (CDCl 3, 100 MHz, 25 C) , , , , , , 127.5, (Figure S13). 15

16 4-cyanobiphenyl. 1 H MR (CDCl 3, 400 MHz, 25 C) 7.67 (m, 4H, ArH), 7.58(m, 2H, ArH), 7.48 (m, 2H, ArH), 7.42 (m, 1H, ArH) (Figure S14). 13 C MR (CDCl 3, 100 MHz, 25 C) , , , , , , , 119.1, 111 (Figure S15). 2-phenylpyridine. 1 H MR (CDCl 3, 400 MHz, 25 C) 8.70 (m, 1H, ArH), 7.99 (m, 2H, ArH), 7.73 (m, 2H, ArH), 7.50 (m, 3H, ArH), 7.23 (m, 1H, ArH) (Figure S16). 13 C MR (CDCl 3, 100 MHz, 25 C) 157.6, , , , , , , , (Figure S17). 3-nitrobiphenyl. 1 H MR (CDCl 3, 500 MHz, 25 C) 8.46 (m, 1H, ArH), 8.19 (m, 1H, ArH), 7.9 (m, 1H, ArH), (m, 3H, ArH), (m, 3H, ArH) (Figure S18). 13C MR (CDCl 3, 125 MHz, 25 C) , , , , , , , , , (Figure S19). 1H and 13 C MR data of nitro reduction product Aniline. 1 H MR (CDCl 3, 400 MHz, 25 C) 7.16 (m, 2H, ArH), 6.77 (m, 1H, ArH), 6.69 (m, 2H, ArH), 3.35 (br. s, 2H, H 2 ). (Figure S20). 13 C MR (CDCl 3, 100 MHz, 25 C) , , , (Figure S21). 4-aminophenol. 1 H MR (DMS-D 6, 400 MHz, 25 C) 6.45 (d, J = 8.56 Hz, 2H, ArH), 6.38 (d, J = 8.56 Hz, 2H, ArH), 4.35 (br. s, 2H, H 2 ). (Figure S22). 13 C MR (DMS-D 6, 100 MHz, 25 C) , , , (Figure S23). 4-cyanoaniline. 1 H MR (CDCl 3, 400 MHz, 25 C) 7.41 (d, J = 8.36 Hz, 2H, ArH), 6.62 (d, J = Hz, 2H, ArH), 4.13 (br. s, 2H, H 2 ). (Figure S24). 13 C MR (CDCl 3, 100 MHz, 25 C) , , , , (Figure S25). 4-(pyridin-4-ylmethyl)aniline. 1 H MR (CDCl 3, 500 MHz, 25 C) 8.46 (d, J = 4.56 Hz, 2H, ArH), 7.10 (d, J = 4.56 Hz, 2H, ArH), 6.94 (d, J = 7.64 Hz, 2H, ArH), 6.63 (d, J = 8.4 Hz, 2H, ArH), 3.86 (s, 2H, CH 2 ), 2.92 (br. s, 2H, H 2 ). (Figure S26). 13 C MR (CDCl 3, 125 MHz, 25 C) , , , , , , , (Figure S27). 4-chloro-1,2-diaminobenzene. 1 H MR (CDCl 3, 500 MHz, 25 C) 6.67 (d, J = 2.5 Hz, 1H, ArH), 6.66 (m, 1H, ArH), 6.65 (d, J = 8.5 Hz, 1H, ArH), 3.23 (br. s, 1H, H 2 ). (Figure S28). 13 C MR (CDCl 3, 125 MHz, 25 C) , , , , , (Figure S29). 1H and 13 C MR data of tandem type reaction product 4-aminobiphenyl. 1 H MR (CDCl 3, 400 MHz, 25 C) 7.34 (m, 5H, ArH), 7.53 (m, 4H, ArH). (Figure S30). 13 C MR (CDCl 3, 100 MHz, 25 C) , , , , , , , (Figure S31). 3-aminobiphenyl. 1 H MR (CDCl 3, 500 MHz, 25 C) 7.56 (m, 2H, ArH), 7.42 (m, 2H, ArH), 7.33 (m, 1H, ArH), 7.25 (m, 1H, ArH), 7.04 (m, 1H, ArH), 6.99 (m, 1H, ArH), 6.75 (m, 1H, ArH). (Figure S32). 13C MR (CDCl 3, 125 MHz, 25 C) , , , , , , , , , (Figure S33). 16

17 Figure S4. 1 H MR of 1 in DMS-D 6 Figure S5. 13 C MR of 1 in DMS-D 6 17

18 Figure S6. 1 H MR of 4-methoxybiphenyl in CDCl 3 Figure S7. 13 C MR of 4-methoxybiphenyl in CDCl 3 18

19 Figure S8. 1 H MR of 4-methylbiphenyl in CDCl 3 Figure S9. 13 C MR of 4-methylbiphenyl in CDCl 3 19

20 Figure S10. 1 H MR of 4-acetylbiphenyl in CDCl 3 Figure S C MR of 4-acetylbiphenyl in CDCl 3 20

21 Figure S12. 1 H MR of 4-nitrobiphenyl Figure S C MR of 4-nitrobiphenyl in CDCl 3 21

22 Figure S14. 1 H MR of 4-cyanobiphenyl in CDCl 3 Figure S C MR of 4-cyanobiphenyl in CDCl 3 22

23 Figure S16. 1 H MR of 2-phenylpyridine in CDCl 3 Figure S C MR of 2-phenylpyridine in CDCl 3 23

24 Figure S18. 1 H MR of 3-nitrobiphenyl in CDCl 3 Figure S C MR of 3-nitrobiphenyl in CDCl 3 24

25 Figure S20. 1 H MR of aniline in CDCl 3 Figure S C MR of aniline in CDCl 3 25

26 Figure S22. 1 H MR of 4-aminophenol in DMS-D 6 Figure S C MR of 4-aminophenol in DMS-D 6 26

27 Figure S24. 1 H MR of 4-cyanoaniline in CDCl 3 Figure S C MR of 4-cyanoaniline in CDCl 3 27

28 Figure S26. 1 H MR of 4-(pyridin-4-ylmethyl)aniline in CDCl 3 Figure S C MR of 4-(pyridin-4-ylmethyl)aniline in CDCl 3 28

29 Figure S28. 1 H MR of 4-chloro-1,2-diaminobenzene in CDCl 3 Figure S C MR of 4-chloro-1,2-diaminobenzene in CDCl 3 29

30 Figure S30. 1 H MR of 4-aminobiphenyl in CDCl 3 Figure S C MR of 4-aminobiphenyl in CDCl 3 30

31 Figure S32. 1 H MR of 4-aminobiphenyl in CDCl 3 Figure S C MR of 3-aminobiphenyl in CDCl 3 31

32 References. 1. D. D. Perrin and W. L. F. Armarego, Purification of Laboratory Chemicals. 3rd Ed, J. Catalan, F. Fabero, M. Soledad Guijarro, R. M. Claramunt, M. D. Santa Maria, M. d. l. C. Foces-Foces, F. Hernandez Cano, J. Elguero and R. Sastre, Journal of the American Chemical Society, 1990, 112, G. M. Sheldrick, International Union of Crystallography, Crystallographic Symposia, 1991, 5, K. Matos and J. A. Soderquist, Journal of rganic Chemistry, 1998, 63, A. K. Shil and P. Das, Green Chem., 2013, 15, K. Layek, M. L. Kantam, M. Shirai, D. ishio-hamane, T. Sasaki and H. Maheswaran, Green Chem., 2012, 14,