"Aprotic" solvolysis of p-toluenesulfinic esters

Construction of a (3aR,4R,9bR)-Hexahydropyrroloquinoline by Stereoselective Hydrogen-Mediated Domino Cyclization

“…Moreover, [Ir­(cod) 2 ]­BF 4 and [Rh­(cod)­Cl] 2 (neutral complex) did not give 16 and gave only small amounts of syn -18 . Reduction of a carbonyl group in lactam ( syn -18 → syn -17 ). We predicted that the hydrogenation of syn -18 would not proceed in the absence of sulfonate anion, because the hydrogenation of 19 using the neutral rhodium complex ([Rh­(cod)­Cl] 2 ) stopped at syn -18 . Additionally, it has been reported that N -methyl-2-pyrrolidine can be isolated as an N -methyl-2-pyrrolidonium tosylate salt . Therefore, on the one hand, we thought that the iminium form of syn -18 generated by trifluoromethanesulfonic acid (formed from the trifluoromethanesulfonate anion of [Rh­(cod) 2 ]­OTf and a proton from heterolytic cleavage of H 2 ), could be easily hydrogenated by the rhodium-bisphosphine catalyst in the reaction mixture.…”

“…Additionally, it has been reported that N-methyl-2-pyrrolidine can be isolated as an N-methyl-2-pyrrolidonium tosylate salt. 15 Therefore, on the one hand, we thought that the iminium form of syn-18 generated by trifluoromethanesulfonic acid (formed from the trifluoromethanesulfonate anion of [Rh(cod) 2 ]OTf and a proton from heterolytic of H 2 ), could be easily hydrogenated by the rhodium-bisphosphine catalyst in the reaction mixture. On the other hand, the effect of protection group was contributed to facilitate this step, because PMB-protected 19 did not proceed in this step.…”

Formale Totalsynthese von (±)‐Isocomen durch Anwendung der α‐Alkinon‐Cyclisierung

“…s, H-C(3)); 2,8 2.6 (M, 1 H); 2,07 (I-artiges m, CH,-C(4)); 2,0-1,2 (m, 6 H); 1.18 (s, CH,-C(I)). MS (70eV): 150 (21), 135 (loo), 122 (17), 107 (ll), 91 (14), 79 (28), 67 (12) 1440~1, 1405w, 1370w, 1300w, 1240w, 1150w, 1 3,4-T~imethy1-4-vinylbic.velo(3.3.~i] (2)); 63,0,48,5 (C(3), C(5)); 54,1,48,9 (C(l), C(4)); 34,2, 28,4, 27,O (C(6), C(7), C(8)); 83, 15,6,303 (3 CH,). MS (70 eV): 194 (5), 176 ( I I), 161 (21), 147 (22), 11 1 (39), 97 ( 5 0 ) , 83 (67), 67 (64), 55 (75).…”

“…180 mmol NaH (erhalten durch mehrmaliges Waschen von 8,O g 55-60proz. Oldispersion von NaH rnit Hexan) und l5,3 g (90,O mmol) p-Toluolsul~nsaure-methylester (hergestellt nach [28] 1450m, 1375m, 1325m, 1310w, 1280m, 1240w, 1210w, 1140~1, 980w, 9 0 0~. 880w,, 8 5 5~.…”

“…180 mmol NaH (erhalten durch mehrmaliges Waschen von 8,O g 55-60proz. Oldispersion von NaH rnit Hexan) und l5,3 g (90,O mmol) p-Toluolsul~nsaure-methylester (hergestellt nach [28]) in 150 ml 1,2-Dimethoxyethan (DME) unter Riihren und Ruckfluss innerhalb von 30 min eine Lsg. von 13,7 g (90.0 mmol) 6 in 10 ml DME getropft und 3 h unter Riihren und Riickfluss erhitzt.…”