SUPPORTING INFORMATION

Transcription

1 Electronic Supplementary Material (ESI) for RSC Advances. This journal is The Royal Society of Chemistry 24 SUPPORTIG IFORMATIO Polymethylhydrosiloxane Derived Palladium anoparticles for Chemo- and Regioselective Hydrogenation of Aliphatic and Aromatic itro Compounds in Water Dandu Damodara, a Racha Arundhathi, a T. Venkata Ramesh Babu, a Margaret K. Legan, b Hephzibah Kumpaty b and Pravin R Likhar a * a Inorganic and Physical Chemistry Division, CSIR- Indian Institute of Chemical Technology, Hyderabad-57, India. b Chemistry Department, Wisconsin University, Whitewater- WI USA. *Corresponding author. Tel.: ; Fax: address: plikhar@iict.res.in COTETS. General Information S-2 2. Preparation of the catalysts S-2-S-3 3. Catalyst Characterization S-3-S-5 4. Typical Experimental Procedure S-6 5. Stability and Reusability of the catalyst S-6-S-7 6. Spectroscopic data of representative compounds S-7-S-3 7. H MR spectra of the products S-3-S C MR spectra of the products S-23-S References S-32 S-

2 General Information All reagents were purchased from commercial suppliers and used without further purification. All solvents were dried and distilled by standard methods. Purification of products was carried out by column chromatography using commercial column chromatography grade silica gel (6-2 mesh) purchased from s. d. fine-chemicals Ltd. using mixture of ethyl acetate and hexane as eluting agent and the products were visualized by UV detection. H MR and 3 C MR (3 or 4 MHz and 75 or MHz, respectively) spectra were recorded in CDCl 3 and DMSO. Chemical shifts (δ) were reported in ppm using TMS as internal standard, and spin - spin coupling constants (J) are given in Hz. H MR and 3 C MR of the compounds were proved either by comparison to the known compounds or the synthesized compounds according to the literature. X-ray powder diffraction (XRD) data were collected on a Simens/D-5 diffractometer using Cu Kα radiation. XPS spectra were recorded on a Kratos AXIS 65 with a dual anode (Mg and Al) apparatus using the Mg Kα anode. The pressure in the spectrometer was about -9 Torr. The particle size and external morphology of the samples were observed on a transmission electron microscope (TEM). Procedure for the synthesis of palladium catalyst: The catalysts Pd-HAP, Pd-FAP, Pd/MgO, Pd/Al 2 O 3, Pd/TiO 2, Pd/SiO 2 and Pd/HT were prepared using literature procedures. 2 Pd/C was procured commercially and was used as received. The preparation procedure of AP-MgO-Pd()PS catalyst given below. Procedure for the synthesis of AP-MgO-Pd()PS catalyst: S-2

3 AP-Mg-PdCl 4 : The brown colored AP-Mg-PdCl 4 was obtained 3 by treating AP-MgO (BET 6 m 2 g -, g) with a 2 PdCl 4 (294 mg, mmol) and dissolved in ml decarbonated water with stirring for 2 h, maintaining a nitrogen atmosphere. The obtained catalyst was filtered, washed with deionized water, acetone and dried at 65 o C in oven. AP-Mg-Pd()PS: AP-Mg-PdCl 4 ( g) catalyst was reduced with PMHS (.75 ml, 2 mmol ) in 3 ml ethylene glycol for 2 h in a round bottom flask under nitrogen atmosphere. After this finally we got the desired black-colored, air-stable AP-Mg-Pd()PS (Pd.99 mmolg - ). As obtained AP-Mg-Pd()PS catalyst was characterized before and after 5 th cycle of the hydrogenation reaction. The catalyst was reused five times without significant loss of catalytic activity. The SEM and TEM analysis showed that the particle size and morphology should be almost identical before and after the reaction. Characterization of synthesized AP-MgO-Pd()PS catalyst: Figure. XRD patterns of a) AP-Mg-PdCl 4 ; b) AP-Mg-Pd()PS catalyst S-3

4 The X-ray powder diffraction (XRD) patterns of AP-Mg-PdCl 4 and fresh AP-Mg-Pd()PS catalyst are shown in Figure. The XRD pattern of the AP-Mg-Pd()PS displayed diffraction lines at 2θ = 4., 46.5 indicates the formation of metallic Pd phase. SEM patterns of [AP-MgO-Pd()PS] catalyst: (a) Fresh (b) Used Fig. (a) SEM images of freshly prepared AP-Mg-Pd()PS, (b) Recovered AP-Mg-Pd()PS catalyst after 5 th cycle. XPS analysis of synthesized AP-MgO-Pd()PS catalyst: S-4

5 Figure 2. XPS analysis of (a) AP-Mg-PdCl 4 and (b) AP-Mg-Pd()PS catalyst. The X-ray photoelectron spectroscopic (XPS) investigation of the prepared AP-Mg-Pd()PS shows a Pd 3d 5/2 line at ev which is an evidence that the Pd metal is in zero oxidation state and stabilized to large extent. TEM analysis of AP-Mg-Pd()PS catalyst: (a) (a) Fresh (b) Used Fig 2. (A) Transmission electron micrographs of AP-Mg-Pd()PS catalyst freshly prepared and (B) recovered catalyst after 5 th cycle. S-5

6 General procedure for the reduction of nitroarenes to amines: A 5 ml round bottom flask was charged with nitrocompound ( mmol), triethylamine (.72 mmol), AP-Mg-Pd()PS (.2 g, Pd:.98 mol%), and 3 ml water. PMHS (4 mmol) was slowly added (drop-wise) to avoid violent evolution of gas under nitrogen atmosphere. The reaction was stirred for required period of time at 8 o C. After completion of the reaction as judged by TLC, the reaction flask was opened to the air, diluted with 5 ml of diethyl ether, and stirred for 5 minutes. The layers were separated and the aqueous layer was back extracted with diethyl ether. The resulting products were purified by flash column chromatography and characterized by using H MR and 3 C MR (see Supporting Information) spectroscopic methods. Stability and efficiency of the catalyst, in large scale hydrogenation 2-chloro nitrobenzene. a Substrate Product Yield(%) b Selectivity(%) 2-chloro nitrobenzene 2-chloro aniline 9 97 a Reaction conditions: 2-chloro nitrobenzene ( mmol), AP-Mg-Pd()PS (.2 g, Pd:.98 mol%), Et 3 (7.5 mmol), PMHS (4 mmol), H 2 O (3 ml), 8 o C for 2h. Reusability of the catalyst: Table. Recyclability of the catalyst AP-Mg-Pd()PS for the reduction of alicyclic nitro compound. a S-6

7 o. of cycles Run Run 2 Run 3 Run 4 Run 5 itrocyclohexane a Reaction conditions: nitrocyclohexane (. mmol), AP-Mg-Pd()PS (.2 g, Pd:.98 mol%), Et 3 (.75 mmol), PMHS (4 mmol), H 2 O (3 ml). Table 2. Recyclability of the catalyst AP-Mg-Pd()PS for the reduction of aromatic nitro compound. a o. of cycles Run Run 2 Run 3 Run 4 Run 5 4-itrobenzaldehyde a Reaction conditions: 4-nitrobenzaldehyde (. mmol), AP-Mg-Pd()PS (.2 g, Pd:.98 mol%), Et 3 (.75 mmol), PMHS (4 mmol), H 2 O (3 ml). Spectroscopic characterization of the products 4-Aminopyridine: (Table 2, entry ) H MR (3 MHz, CDCl 3, ppm): δ 8.2 (d, J = 6. Hz, 2H), 6.52 (d, J = 6.25 Hz, 2H), 4.8 (bs, 2H); 3 C MR (75 MHz, CDCl 3, ppm): δ 53.4, 49., S-7

8 2-Aminopyrimidine: (Table 2, entry 3) H MR (3 MHz, CDCl 3, ppm): δ 8.3 (d, J = 7.43 Hz, 2H), 6.62 (t, J = 4.8 Hz, H) 5.4 (bs, 2H); 3 C MR (75 MHz, CDCl 3, ppm): δ 63.8, 58.27,.6. S Thiazole-2-amine: (Table 2, entry 7) H MR (3 MHz, CDCl 3, ppm): δ (d, J = 3.77 Hz, H), (d, J = 3.58 Hz, H), 5.35 (bs, 2H); 3 C MR (75 MHz, CDCl 3, ppm): δ 68.4, 38.5, 8.2. H 2-Aminoimidazole: (Table 2, entry 9) H MR (3 MHz, CDCl 3, ppm): δ.35 (s, H), 7.2 (s, 3H); 3 C MR (75 MHz, CDCl 3, ppm): δ 35.7, Amino quinoline: (Table 2, entry 3) S-8

9 H MR (3 MHz, CDCl 3, ppm): δ 8.5 (s, H), 7.96 (d, J = 9.6, H), 7.58 (d, J = 9.3 Hz, H), 7.43 (t, J = 7.7, 6.86 Hz, 2H), 7.22 (s, H), 3.95 (s, 2H); 3 C MR (75 MHz, CDCl 3, ppm): δ 42.34, 4.96, 3.52, 29., 28.6, 26.67, 26.2, H 2 H 6-Amino indazole: (Table 2, entry 4) H MR (3 MHz, CDCl 3, ppm): δ.34 (bs, H), 8. (s, H), 7.78 (d, J = 8.24 Hz, H), 7.5 (d, J = 9.3 Hz, H), 7.8 (s, H), 3.98 (bs, 2H); 3 C MR (75 MHz, CDCl 3, ppm): δ 42.67, 4.4, 34.99, 26.76, 23.22, 2.94, Vinylaniline: (Table 3, entry ) H MR (3 MHz, CDCl 3, ppm): δ 7.8 (d, J = 6.56 Hz, 2H), (m, 3H), 5.5 (d, J = 8.76 Hz, H), 5. (d, J = 3.27 Hz, H), 3.59 (bs, 2H); 3 C MR (75 MHz, CDCl 3, ppm): δ 46.5, 36.69, 27.34, 5.4, aphthalene -amine: (Table 3, entry 5) S-9

10 H MR (3 MHz, CDCl 3, ppm): δ (m, 2H), (m, 2H), (m, 3H), 6.8 (bs, 2H); 3 C MR (75 MHz, CDCl 3, ppm): δ 4.98, 28.49, 26.3, 25.64, 24.66, 2.99, 2.6, 9.8, 2.62, Cyclohexylamine: (Table 3, entry 8) H MR (3 MHz, CDCl 3, ppm): δ (m, H), (m, 6H), (m, 4H); 3 C MR (75 MHz, CDCl 3, ppm): δ 49.78, 36., 25., n-butyl amine: (Table 3, entry ) H MR (3 MHz, CDCl 3, ppm): δ (m, 2H), (m, 2H), (m, 2H), (m, 3H); 3 C MR (75 MHz, CDCl 3, ppm): δ 49.6, 32., 2.3, 3.7. n-hexyl amine: (Table 3, entry 2) H MR (3 MHz, CDCl 3, ppm): δ (t, J = 6.79 Hz, 2H),.86 (bs, 2H), (m, 2H),.29 (s, 4H), (m, 3H); 3 C MR (75 MHz, CDCl 3, ppm): δ 42., 33.4, 3.5, 26.4, 22.5, 3.9. S-

11 S 4- (phenylthio)aniline: (Table 3, entry 4) H MR (3 MHz, CDCl 3, ppm): δ (m, 2H), (m, 2H), (m, 3H), 6.6 (d, J = 8.2 Hz, 2H), 3.67 (bs, 2H); 3 C MR (75 MHz, CDCl 3, ppm): δ 45.9, 4.2, 35.98, 29., 27.64, 25.9, 2.92, 6.7. Aniline: (Table 4, entry ) H MR (3 MHz, CDCl 3, ppm): δ (m, 2H), (t, J = 7.55 Hz, H), (d, J = 7.55 Hz, 2H), 3.59 (bs, 2H); 3 C MR (75 MHz, CDCl 3, ppm): δ 46.2, 29., 8.2, 4.9. H 3 CO 4-Methoxy aniline: (Table 4, entry 2) H MR (3 MHz, CDCl 3, ppm): δ (m, 4H), 3.74 (s, 2H),3.4 (bs, 2H); 3 C MR (75 MHz, CDCl 3, ppm): δ 52.6, 39.9, 6.3, 4.7, S-

12 Br 2-Bromo aniline: (Table 4, entry 3) H MR (3 MHz, CDCl 3, ppm): δ (d, J = 7.99 Hz, H), (t, J = 6.99 Hz, H), (d, J = 6.99 Hz, H), (t, J = 6.99 Hz, H), 4.4 (bs, 2H); 3 C MR (75 MHz, CDCl 3, ppm): δ 43.9, 32.4, 28.2, 9.2, 5.6, 9.. O 2 4-itroaniline: (Table 4, entry 7) H MR (3 MHz, CDCl 3, ppm): δ 8.3 (d, J = 9.46 Hz, 2H) 6.63 (d, J = 8.67 Hz, 2H), 5. (bs, 2H); 3 C MR (75 MHz, CDCl 3, ppm): δ 53.76, 37.2, 25.72, OHC 4-Amino benzaldehyde: (Table 4, entry 8) H MR (3 MHz, CDCl 3, ppm): δ.3 (s, H), 8. (d, J = 7.84 Hz, 2H), 7.56 (d, J = 7.34 Hz, 2H); 3 C MR (75 MHz, CDCl 3, ppm): δ 7, 49,39, 28, 24. HOOC S-2

13 4-Amino Benzoic acid: (Table 4, entry ) H MR (3 MHz, CDCl 3 +DMSO, ppm): δ (d, J = 8.49 Hz, 2H), (d, J = 9.55 Hz, 2H), 5.4 (bs, 2H); 3 C MR (75 MHz, CDCl 3 +DMSO, ppm): δ 68.3, 5.3, 3.2, 8.5, 3.. C 2 H 5 OOC Ethyl 4-aminobenzoate: (Table 4, entry 2) H MR (3 MHz, CDCl 3, ppm): δ 7.85 (d, J = 9.6 Hz, 2H), 6.63 (d, J = 9.6 Hz, 2H), 4.3(q, J = 6.7, 7.5 Hz, 2H), 4. (bs, 2H),.36 (t, J = 6.7, 7.5 Hz, 3H); 3 C MR (75 MHz, CDCl 3, ppm): δ 66.69, 5.7, 3.52, 2.5, 3.65, 6.3, 4.3. H MR spectra of the products: S-3

14 S S-4

15 H S-5

16 H 2 H H S-6

17 S-7

18 S-8

19 S H S-9

20 O Br S-2

21 O CHO H S-2

22 O OH H O O S-22

23 3 C MR spectra of the products: S-23

24 S H S-24

25 H 2 H S-25

26 H S-26

27 S-27

28 H S H S-28

29 OCH 3 H S-29

30 Br O S-3

31 OHC O OH H S-3

32 O O H References:. (a) R. Dey,. Mukherjee, S. Ahammed and B. C. Ranu, Chem. Commun., 22,48, ; (b) Jr. R. J. Rahaim and Jr. R. E. Maleczka, Org. Lett., 25, 7, ; (c) K. Junge, B. Wendt,. Shaikh and M. Beller, Chem. Commun., 2,46, (a) A. Cwik, Z. Hell, F. Figueras, Adv. Synth. Catal. 26, 348, 523; (b) K. Mori, K. Yamaguchi, T. Hara, T. Mizugaki, K. Ebitani, K, Kaneda, J. Am. Chem. Soc., 22, 24, 572; (c) M. L. Kantam, K. B. S. Kumar, P. Srinivas, B. Sreedhar, Adv. Synth. Catal., 27, 349, 4. (d) J. M. D. Consul, C. A. Peralta, E. V. Benvenutti, J. A. C. Ruiz, H. O. Pastore and I. M. Baibich, J. Mol. Catal. A: Chem., 26, 246, (a) M. L. Kantam, S. Roy, M. Roy, B. Sreedhar and B. M. Choudary, Adv. Synth. Catal., 25, 347, 22-28; (b) Keya Layek, H. Maheswaran, R. Arundhathi, M. L. Kantam and S. K. Bhargava, Adv. Synth. Catal., 2, 353, 66 66; (c) M. L. Kantam, R. Chakravarti, U. Pal, B. Sreedhar and Suresh Bhargava, Adv. Synth. Catal., 28, 35, S-32