Palladium-Catalyzed Cyclization Reactions of Acetylene-Containing ...

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Palladium-Catalyzed Cyclization Reactions of Acetylene-Containing Amino AcidsFULL PAPERS2-[5-(4-Methoxybenzylidene)-2-oxo-tetrahydrofuran-3-yl]isoindole-1,3-dione (29)Following the general procedure B, to a solution of (S)-16 (50 mg,0.21 mmol) in MeCN (2.0 mL), Et 3 N (142 mL, 1.03 mmol), TBAC (114 mg,0.41 mmol), 4-iodoanisole (96 mg, 0.41 mmol) and Pd(PPh 3 ) 4 (24 mg,0.03 mmol) were added. Work-up and purification afforded 29 as a yellowoil; yield: 29 mg (0.08 mmol, 45%). 29: 1 H NMR (400 MHz, CDCl 3 ): d ˆ7.90 ± 7.87 (m, 2H), 7.80 ± 7.76 (m, 2H), 7.16 ± 7.12 (m, 2H), 6.88 ± 6.85 (m,2H), 6.41 (t, J ˆ 1.9 Hz, 1H), 5.27 (t, J ˆ 9.9 Hz, 1H), 3.70 (s, 3H), 3.51 ± 3.47(m, 2H); 13 C NMR (100 MHz, CDCl 3 ): d ˆ 169.5, 166.5, 158.5, 145.4, 134.5,131.4, 128.9, 125.9, 123.7, 114.0, 114.0, 55.1, 46.9, 30.3; IR (film): n ˆ 1807,1778, 1716, 1683, 1397 cm 1 ; HRMS (EI): calcd. for C 20 H 15 NO 5 349.0950,found 349.0924.(R)-5-Methylene-1-(4-toluenesulfonyl)pyrrolidine-2-carboxylic Acid Methyl Ester (33)Following the general procedure C, to a solution of (R)-19 (50 mg,0.17 mmol) in THF (2.0 mL) were added K 2 CO 3 (117 mg, 0.85 mmol),Pd(OAc) 2 (4.0 mg, 0.02 mmol) and PPh 3 (19 mg, 0.07 mmol). Work-up andpurification afforded (R)-33 as a yellowoil; yield: 37 mg (0.125 mmol, 74%).(R)-33: [a] D : 50.5 (c 1, CH 2 Cl 2 ); 1 H NMR (400 MHz, C 6 D 6 ): d ˆ 7.93 (d,J ˆ 8.3 Hz, 2H), 6.79 (d, J ˆ 8.1 Hz, 2H), 5.52 (d, J ˆ 1.2 Hz, 1H), 4.71 (dd,J ˆ 4.7 Hz, 8.2 Hz, 1H), 4.23 (d, J ˆ 1.3 Hz, 1H), 3.39 (s, 3H), 2.22 ± 2.13 (m,131H), 1.88 (s, 3H), 1.80 ± 1.69 (m, 1H), 1.51 ± 1.41 (m, 2H); C NMR(100 MHz, CDCl 3 ): d ˆ 172.6, 145.2, 144.4, 137.2, 130.2, 128.9, 91.0, 64.5,52.6, 32.0, 30.8, 21.7; IR (film): n ˆ 2921, 2849, 1734, 1162 cm 1 ; HRMS (EI):calcd. for C 14 H 19 NO 4 S 295.0878, found 295.0881.2-[5-(4-tert-Butylcyclohex-1-enylmethylene)-2-oxotetrahydrofuran-3-yl]isoindole-1,3-dione (30)Following the general procedure B, to a solution of (S)-16 (50 mg,0.21 mmol) in THF (2.0 mL) were added Et 3 N (142 ml, 1.03 mmol), TBAC(114 mg, 0.41 mmol), 26 (46 mg, 0.41 mmol) and Pd(PPh 3 ) 4 (24 mg,0.03 mmol). Purification afforded 30 as a white amorphous solid; yield:18 mg (0.05 mmol, 23%). 30: 1 H NMR (200 MHz, CDCl 3 ): d ˆ 7.89 ± 7.84(m, 2H), 7.77 ± 7.74 (m, 2H), 5.92 (d, J ˆ 12.7 Hz, 1H) 5.68 ± 5.66 (m, 1H),5.37 ± 5.16 (m, 1H), 3.96 ± 3.21 (m, 2H), 2.71 ± 2.09 (m, 2H), 1.84 ± 1.52 (m,2H), 1.40 ± 1.09 (m, 3H), 0.85 (s, 9H).2-(6-Benzylidene-2-oxotetrahydropyran-3-yl)isoindole-1,3-dione (31)Following the general procedure B, to a solution of 17 (50 mg, 0.19 mmol) inMeCN (2.0 mL) were added Et 3 N (135 mL, 0.94 mmol), TBAC (107 mg,0.39 mmol), PhI (43 mL, 0.39 mmol) PPh 3 (10 mg, 0.04 mmol) and Pd(OAc) 2(4.3 mg, 0.02 mmol). Purification afforded 31 as a white amorphous solid;yield: 20 mg (0.06 mmol, 31%). 31: 1 H NMR (400 MHz, CDCl 3 ): d ˆ 7.90 ±7.85 (m, 2H), 7.77 ± 7.74 (m, 2H), 7.56 ± 7.53 (m, 2H), 7.39 ± 7.35 (m, 2H),7.28 ± 7.26 (m, 1H), 6.45 (s, 1H), 5.04 (dd, J ˆ 6.4 Hz, 12.3 Hz, 1H), 3.23 ± 3.17(dt, J ˆ 15.8 Hz, 4.4 Hz, 1H), 2.88 ± 2.79 (m, 1H), 2.69 ± 2.58 (dt, J ˆ 12.4 Hz,4.4 Hz, 1H), 2.15 ± 2.08 (m, 1H).General Procedure C for the Amidopalladation Reactions(R)-5-Methyl-1-(4-toluenesulfonyl)-2,3-dihydro-1H-pyrrole-2-carboxylic Acid Methyl Ester (34)Following the general procedure C, to a solution of (R)-19 (50 mg,0.17 mmol) in THF (2.0 mL) were added K 2 CO 3 (117 mg, 0.85 mmol),Pd(OAc) 2 (4.0 mg, 0.02 mmol) and dppb (7.2 mg, 0.02 mmol). Work-up andpurification afforded a 1 :8 mixture of (R)-33 and (R)-34 as a yellowoil; yield:35 mg (0.12 mmol, 70%). (R)-34: 1 H NMR (400 MHz, CDCl 3 ): d ˆ 7.75 (d,J ˆ 8.3 Hz, 2H), 7.31 (d, J ˆ 8.2 Hz, 2H), 4.82 (s, 1H), 4.69 (dd, J ˆ 4.9 Hz,10.9 Hz, 1H), 3.79 (s, 3H), 2.63 ± 2.58 (m, 1H), 2.56 ± 2.55 (m, 1H), 2.43 (s,3H), 2.02 (m, 3H); 13 C NMR (100 MHz, CDCl 3 ): d ˆ 171.7, 143.8, 139.5,138.2, 129.6, 127.5, 108.9, 62.1, 52.5, 32.1, 21.7, 15.0; IR (film): n ˆ 2953, 1743,1346, 1163 cm 1 .(R)-5-Methylene-1-(4-nitrobenzenesulfonyl)pyrrolidine-2-carboxylic Acid Methyl Ester (35)Following the general procedure C, to a solution of (R)-20 (48 mg,0.15 mmol) in THF (2.0 mL) were added K 2 CO 3 (104 mg, 0.74 mmol),Pd(OAc) 2 (4.0 mg, 0.015 mmol) and PPh 3 (8.0 mg, 0.03 mmol). Work-up andpurification afforded (R)-35 as a yellowoil; yield: 23 mg (0.07 mmol, 48%).(R)-35: [a] D : 41.9 (c 1, CH 2 Cl 2 ); 1 H NMR (400 MHz, C 6 D 6 ): d ˆ 8.36 (d,J ˆ 8.9 Hz, 2H), 8.15 (d, J ˆ 8.9 Hz, 2H), 5.52 (d, J ˆ 1.2 Hz, 1H), 4.75 ± 4.72(m, 1H), 4.39 (dd, J ˆ 1.6 Hz, 3.2 Hz, 1H), 3.79 (s, 3H), 2.67 ± 2.59 (m, 1H),132.44 ± 2.40 (m, 1H), 2.40 ± 2.36 (m, 1H), 2.21 ± 1.97 (m, 1H); C NMR(100 MHz, CDCl 3 ): d ˆ 171.4, 150.3, 143.8, 143.3, 128.9, 123.9, 91.2, 63.4,52.6, 31.0, 26.9; IR (film): n ˆ 2956, 1747, 1531, 1351 cm 1 ; HRMS (EI): calcd.for C 13 H 14 N 2 O 6 S 326.0573, found 326.0579.To a solution of the cyclization precursor in DMFor THF were added K 2 CO 3(5 equiv) and the Pd catalyst (10 mol %). The solution was refluxed andmonitored with TLC. Upon completion, the reaction mixture was pouredinto saturated aqueous NaHCO 3 and extracted with ether (3 ). Thecombined organic layers were dried (MgSO 4 ), concentrated and purified byflash chromatography (70% ether/petroleum ether, 1% Et 3 N) to afford thepure product.(S)-1-(4-Toluenesulfonyl)pyrrolidine-2-carboxylic AcidMethyl Ester (32)Following the general procedure C, to a solution of (S)-18 (50 mg,0.18 mmol) in THF (2.0 mL) were added K 2 CO 3 (123 mg, 0.90 mmol) andPd(PPh 3 ) 4 (21 mg, 0.02 mmol). Work-up and purification afforded (S)-32 asa colorless oil; yield: 38 mg (0.14 mmol, 76%). (S)-32: [a] D : 102.9 (c 1,CH 2 Cl 2 ); 1 H NMR (400 MHz, CDCl 3 ); d ˆ 7.69 (d, J ˆ 8.3 Hz, 2H), 7.32 (d,J ˆ 8.1 Hz, 2H), 6.38 ± 6.36 (m, 1H), 5.08 ± 5.06 (m, 1H), 4.25 (dd, J ˆ 7.2 Hz,11 Hz, 1H), 3.79 (s, 3H), 2.80 ± 2.63 (m, 2H), 2.44 (s, 3H);13C NMR(100 MHz, CDCl 3 ): d ˆ 171.4, 144.21, 133.3, 133.0, 130.3, 129.7, 127.7, 109.6,60.0, 52.7, 35.2, 21.5; IR (film): n ˆ 1742, 1355, 1167 cm 1 ; HRMS (EI): calcd.for C 13 H 15 NO 4 S 281.0722, found 281.0722.General Procedure D for the Amidopalladation ReactionsTo a solution of the cyclization precursor in MeCN were added K 2 CO 3(5 equiv), anhydrous TBAC (1 equiv), an aryl halide (5 equiv) and finally aPd(0) catalyst (10 mol %). The solution was heated at reflux and monitoredby TLC. Upon completion, the reaction mixture was poured into saturatedaqueous NaHCO 3 and extracted with ether (3 ). The combined organiclayers were dried (MgSO 4 ), concentrated and purified by flash chromatography(gradient: 20 ! 70% ether/petroleum ether, 1% Et 3 N) to afford thepure product.(R)-5-Benzylidene-1-(4-toluenesulfonyl)pyrrolidine-2-carboxylic Acid Methyl Ester (37)Following the general procedure D, to a solution of (R)-19 (80 mg,0.27 mmol) in MeCN (2.0 mL) were added K 2 CO 3 (187 mg, 1.36 mmol),TBAC (79 mg, 0.27 mmol), PhI (84 mL, 1.36 mmol) and Pd(PPh 3 ) 4 (31 mg,0.03 mmol). Work-up and purification afforded (R)-37 as an amorphoussolid; yield: 74 mg (0.20 mmol, 74%). (R)-37: [a] D : 73.6 (c 0.5, CH 2 Cl 2 );Adv. Synth. Catal. 2002, 344, 70±83 79
FULL PAPERSLarissa B. Wolf et al.1H NMR (400 MHz, CDCl 3 ): d ˆ 7.80 (d, J ˆ 8.3 Hz, 2H), 7.32 ± 7.26 (m,5H), 7.18 ± 7.12 (m, 3H), 6.74 (s, 1H), 4.57 (dd, J ˆ 6.6 Hz, 7.8 Hz, 1H), 3.82 (s,3H), 2.79 ± 2.75 (m, 1H), 2.42 (s, 3H), 2.35-2.30 (m, 1H), 2.15 ± 2.10 (m, 1H),1.94 ± 1.89 (m, 1H); 13 C NMR (100 MHz, CDCl 3 ): d ˆ 171.9, 144.2, 139.8,136.9, 134.7, 129.5, 128.1, 128.0, 126.0, 111.3, 62.4, 52.5, 28.8, 27.3, 21.4; IR(film): n ˆ 2951, 1750, 1653, 1349, 1163 cm 1 ; HRMS (EI): calcd. forC 20 H 21 NO 4 S 371.1191, found 371.1178.(R)-5-(4-Nitrobenzylidene)-1-(4-toluenesulfonyl)pyrrolidine-2-carboxylic Acid Methyl Ester (38)(R)-5-(2-Butylallylidene)-1-(4-toluenesulfonyl)pyrrolidine-2-carboxylic Acid Methyl Ester (41)Following the general procedure D, to a solution of (R)-19 (50 mg,0.17 mmol) in MeCN (2.0 mL) were added K 2 CO 3 (117 mg, 0.85 mmol),TBAC (49 mg, 0.17 mmol), 36 (196 mg, 0.85 mmol) and Pd(PPh 3 ) 4 (20 mg,0.02 mmol). Work-up and purification afforded (R)-41 as an amorphoussolid; yield: 9 mg (0.02 mmol, 13%). (R)-41: 1 H NMR (400 MHz, CDCl 3 ):d ˆ 7.72 (d, J ˆ 8.3 Hz, 2H), 7.28 (d, J ˆ 8.0 Hz, 2H), 6.00 (d, J ˆ 15.8 Hz,1H), 5.57 (td, J ˆ 7.0 Hz, 15.8 Hz, 1H), 5.10 (d, J ˆ 9.2 Hz, 1H), 3.94 ± 3.88(m, 1H), 3.50 (s, 3H), 2.41 (s, 3H), 2.17-2.13 (m, 4H), 1.87 ± 1.68 (m, 2H),1.47 ± 1.40 (m, 2H), 1.37 ± 1.28 (m, 2H), 0.93 ± 091 (m, 3H).Following the general procedure D, to a solution of (R)-19 (50 mg,0.17 mmol) in MeCN (2.0 mL) were added K 2 CO 3 (117 mg, 0.85 mmol),TBAC (49 mg, 0.17 mmol), 1-iodo-4-nitrobenzene (210 mg, 0.85 mmol) andPd(PPh 3 ) 4 (20 mg, 0.02 mmol). Work-up and purification afforded (R)-38 asa yellowoil; yield: 42 mg (0.10 mmol, 59%). (R)-38: [a] D : 152.2 (c 1,CH 2 Cl 2 ); 1 H NMR (400 MHz, CDCl 3 ): d ˆ 8.13 ± 8.09 (m, 3H), 7.83 ± 7.80(m, 3H), 7.60 ± 7.22 (m, 4H), 6.68 (s, 1H), 4.71 (dd, J ˆ 5.2 Hz, 8.2 Hz, 1H),3.82 (s, 3H), 2.87 ± 2.83 (m, 1H), 2.52-2.51 (m, 1H), 2.42 (s, 3H), 2.22 ± 2.14 (m,1H), 2.04 ± 1.97 (m, 1H); 13 C NMR (100 MHz, CDCl 3 ): d ˆ 171.5, 144.7,144.0, 143.1, 141.1, 134.7, 129.6, 129.2, 128.1, 127.1, 123.5, 123.1, 107.7, 62.6,52.6, 29.4, 27.0, 22.1; IR (film): n ˆ 2953, 2925, 2851, 1748, 1641, 1593, 1513,1340 cm 1 ; HRMS (EI): calcd. for C 20 H 20 N 2 O 6 S 416.1042, found 416.1037.(R)-5-(4-Methoxybenzylidene)-1-(4-toluenesulfonyl)-pyrrolidine-2-carboxylic Acid Methyl Ester (39)(R)-5-Benzylidene-1-(4-nitrobenzenesulfonyl)pyrrolidine-2-carboxylic Acid Methyl Ester (42)Following the general procedure D, to a solution of (R)-20 (50 mg,0.15 mmol) in MeCN (2.0 mL) were added K 2 CO 3 (106 mg, 0.77 mmol),TBAC (43 mg, 0.15 mmol), PhI (34 mL, 0.31 mmol) and Pd(PPh 3 ) 4 (18 mg,0.015 mmol). Work-up and purification afforded (R)-42 as a yellowsolid;yield: 50 mg (0.12 mmol, 80%). (R)-42: mp 149 ± 150 8C; [a] D : 129.3 (c 1,CH 2 Cl 2 ); 1 H NMR (400 MHz, CDCl 3 ): d ˆ 8.35 (d, J ˆ 8.9 Hz, 2H), 8.16 (d,J ˆ 8.9 Hz, 2H), 7.32 ± 7.12 (m, 5H), 6.69 (s, 1H), 4.67 (dd, J ˆ 5.6 Hz, 8.2 Hz,1H), 3.83 (s, 3H), 2.85 ± 2.77 (m, 1H), 2.49 ± 2.41 (m, 1H), 2.25 ± 2.15 (m, 1H),2.04 ± 1.96 (m, 1H); 13 C NMR (100 MHz, CDCl 3 ): d ˆ 171.4, 150.4, 143.5,138.5, 136.1, 128.9, 128.3, 128.1, 126.5, 124.0, 111.4, 62.4, 52.7, 28.7, 27.3; IR(film): n ˆ 1717, 1652, 1532, 1350 cm 1 ; HRMS (EI): calcd. for C 19 H 18 N 2 O 6 S402.0886, found 402.0894.Following the general procedure D, to a solution of (R)-19 (50 mg,0.17 mmol) in MeCN (2.0 mL) were added K 2 CO 3 (117 mg, 0.85 mmol),TBAC (49 mg, 0.17 mmol), 4-iodoanisole (198 mg, 0.85 mmol) and Pd(PPh 3) 4 (20 mg, 0.02 mmol). Work-up and purification afforded (R)-39 as anamorphous solid; yield: 39 mg (0.10 mmol, 58%). (R)-39: [a] D : 78.2 (c 1,CH 2 Cl 2 ); 1 H NMR (400 MHz, CDCl 3 ): d ˆ 7.78 (d, J ˆ 8.3 Hz, 2H), 7.28 (d,J ˆ 8.0 Hz, 2H), 7.06 (d, J ˆ 8.6 Hz, 2H), 6.83 (dd, J ˆ 2.0 Hz, 6.8 Hz, 2H),6.72 (s, 1H), 4.54 (dd, J ˆ 7.0 Hz, 7.6 Hz, 1H), 3.82 (s, 3H), 3.79 (s, 3H), 2.80 ±2.65 (m, 1H), 2.42 (s, 3H) 2.33 ± 2.26 (m, 1H), 2.23 ± 2.05 (m, 1H), 1.95 ± 1.82(m, 1H); 13 C NMR (400 MHz, CDCl 3 ): d ˆ 171.9, 157.9, 144.1, 137.6, 134.7,129.4, 129.2, 127.6, 113.6, 111.5, 62.3, 55.1, 52.5, 28.6, 27.3, 21.4; IR (film): n ˆ2952, 2838, 1740, 1654, 1606, 1511, 1163 cm 1 ; HRMS (EI): calcd. for C 21 H 23NO 5 S 401.1297, found 401.1303.(R)-N-(1-Hydroxymethylbut-3-ynyl)-4-methylbenzenesulfonamide(43)To a solution of LiAlH 4 (531 mg, 3.76 mmol) in dry THF (20 mL) (R)-13(250 mg, 0.94 mmol) was added in portions. After stirring for 16 h, theLiAlH 4 was carefully quenched by dropwise adding 1 M HCl at 0 8C. Thereaction mixture was extracted with ether (3 20 mL) and the combinedorganic layers were dried (MgSO 4 ) and concentrated. Without furtherpurification (R)-43 was obtained as white solid; yield: 249 mg (0.98 mmol,100%). (R)-43: [a] D : ‡ 51.0 (c 1.6, CH 2 Cl 2 ); 1 H NMR (400 MHz, CDCl 3 ):d ˆ 7.78 (d, J ˆ 8.3 Hz, 2H), 7.31 (d, J ˆ 8.0 Hz, 2H), 4.94 (d, J ˆ 7.9 Hz, 1H),3.72 ± 3.86 (m, 1H), 3.64 ± 3.59 (m, 1H), 3.45 ± 3.40 (m, 1H), 2.46 ± 2.39 (m,1H), 2.44 (s, 3H), 2.36 ± 2.33 (dd, J ˆ 2.7 Hz, 6.8 Hz, 1H), 1.98 (t, J ˆ 2.7 Hz,1H), 1.81 (bs, 1H); IR (film): n ˆ 3503, 3280, 2925, 1328 cm 1 ; HRMS (FAB):calcd. for C 12 H 16 NO 3 S (MH ‡ ) 254.0851, found 254.0845.(R)-5-(4-tert-Butylcyclohex-1-enylmethylene)-1-(4-toluenesulfonyl)pyrrolidine-2-carboxylic Acid Methyl Ester(40)Following the general procedure D, to a solution of (R)-19 (50 mg,0.17 mmol) in MeCN (2.0 mL) were added K 2 CO 3 (117 mg, 0.85 mmol),TBAC (49 mg, 0.17 mmol), 26 (242 mg, 0.85 mmol) and Pd(PPh 3 ) 4 (20 mg,0.02 mmol). Work-up and purification afforded (R)-40 as an amorphoussolid; yield: 40 mg (0.09 mmol, 55%). (R)-40: [a] D : 30.4 (c 1, CH 2 Cl 2 );1H NMR [400 MHz, CDCl 3 , several signals are double due to the s(cis, trans)rotamers]: d ˆ 7.73 (d, J ˆ 8.0 Hz, 2H), 7.28 (d, J ˆ 8.1 Hz, 2H), 6.17 (s, 0.5H),6.15 (s, 0.5H), 5.52 (s, 0.5H), 5.41 (s, 0.5H), 4.46 ± 4.42 (m, 1H), 3.79 (s, 3H),2.52 ± 2.41 (m, 1H), 2.15 ± 2.02 (m, 5H), 1.88 ± 1.80 (m, 3H), 1.22 ± 1.13 (m,2H), 0.86 (s, 9H); 13 C NMR (100 MHz, CDCl 3 ): d ˆ 171.8, 143.6, 136.3, 133.8,131.1, 129.3, 127.2, 115.4, 115.0, 62.1, 52.4, 43.5, 36.4, 30.3, 30.0, 28.8, 27.2,27.0, 27.0, 21.4; IR (film): n ˆ 2950, 2390, 2380, 1745, 1700 cm 1 ; HRMS (EI):calcd. for C 24 H 33 NO 4 S 431.2130, found 431.2119.(S)-N-(1-Hydroxymethylpent-4-ynyl)-4-methylbenzenesulfonamide(44)To a solution of LiAlH 4 (750 mg, 19.8 mmol) in dry THF (25 mL) (S)-14(1.40 g, 4.90 mmol) was added in portions. After stirring for 16 h, the LiAlH 4was carefully quenched by dropwise adding 1 M HCl at 08C. The reactionmixture was extracted with ether (3 20 mL) and the combined organiclayers were dried (MgSO 4 ) and concentrated. Without further purification(S)-44 was obtained as white solid; yield: 1.41 mg (5.26 mmol, 100%). (S)-44:[a] D : 19.5 (c 1, CH 2 Cl 2 ); 1 H NMR (400 MHz, CDCl 3 ): d ˆ 7.78 (d, J ˆ8.3 Hz, 2H), 7.31 (d, J ˆ 8.0 Hz, 2H), 4.92 (d, J ˆ 8.2 Hz, 1H), 3.61 ± 3.39 (m,3H), 2.43 (s, 3H), 2.17 ± 2.09 (m, 2H), 1.92 (t, J ˆ 2.6 Hz, 1H), 1.73 ± 1.60 (m,2H); 13 C NMR (400 MHz, CDCl 3 ): d ˆ 143.5, 137.3, 129.6, 127.0, 81.9, 69.2,64.2, 54.5, 30.3, 21.4, 14.8; IR (film): n ˆ 3470, 3283, 1433, 1308, 1155 cm 1 ;HRMS (FAB): calcd. for C 13 H 18 NO 3 S (MH ‡ ) 268.1007, found 268.1004.80 Adv. Synth. Catal. 2002, 344, 70±83
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