Nucleophilic addition to olefins. Part 23. High intrinsic rate constant and large imbalances in the thiolate ion addition to substituted .alpha.-nitrostilbenes
作者:Claude F. Bernasconi、Robert B. Killion
DOI:10.1021/ja00230a038
日期:1988.10
Addition d'ions thiolates RS − (R=Et, HOCH 2 CH 2 , CH 3 OCOCH 2 CH 2 , et CH 3 OCOCH 2 ) a l'α-nitrostilbene et de HOCH 2 CH 2 S − a des α-nitrostilbenes substitues sur l'α-phenyl (Me-4, H, Br-4, NO 2 -3, et NO 2 -4)
加成 d' 离子硫醇盐 RS − (R=Et, HOCH 2 CH 2 , CH 3 OCOCH 2 CH 2 , et CH 3 OCOCH 2 ) a l'α-nitrostilbene et de HOCH 2 CH 2 S − a des α-nitrostilbenes sur l'α-苯基 (Me-4, H, Br-4, NO 2 -3, et NO 2 -4)
Stereospecific approach to α,β-disubstituted nitroalkenes via coupling of α-bromonitroalkenes with boronic acids and terminal acetylenes
作者:Madhu Ganesh、Irishi N.N. Namboothiri
DOI:10.1016/j.tet.2007.09.012
日期:2007.11
(Z)-alpha-Bromo-beta-substituted nitroethylenes undergo facile Suzuki coupling with aryl, heteroaryl, and vinylboronic acids in the presence of Pd(PPh3)(4) as catalyst to afford (E)-alpha,beta-disubstituted nitroethylenes in high yield (up to 95%) and complete specificity. Similar coupling of alpha-bromonitroethylenes with terminal acetylenes (Sonogashira coupling) provides a novel route to (E)-nitroenynes. These Pd-catalyzed coupling methods offer a convenient and stereospecific entry into a diverse array of synthetically and biologically useful alpha,beta-disubstituted nitroethylenes. (c) 2007 Elsevier Ltd. All rights reserved.
Nucleophilic addition to olefins. 20. Large transition state imbalances in the reaction of .alpha.-nitrostilbenes with amines