Domino Aryne Annulation via a Nucleophilic–Ene Process
摘要:
1,2-Benzdiyne equivalents possess the unique property that they can react with two arynophiles through iteratively generated 1,2- and 2,3-aryne intermediates. Upon rational modification on the second leaving group of these aryne precursors, a domino aryne annulation approach was developed through a nucleophilic-ene reaction sequence. Various benzo-fused N-heterocyclic frameworks were achievable under transition metal-free conditions with a broad substrate scope.
Domino Aryne Annulation via a Nucleophilic–Ene Process
摘要:
1,2-Benzdiyne equivalents possess the unique property that they can react with two arynophiles through iteratively generated 1,2- and 2,3-aryne intermediates. Upon rational modification on the second leaving group of these aryne precursors, a domino aryne annulation approach was developed through a nucleophilic-ene reaction sequence. Various benzo-fused N-heterocyclic frameworks were achievable under transition metal-free conditions with a broad substrate scope.
A New Method for the Generation and Cyclization of Iminyl Radicals via the Hudson Reaction
作者:Xichen Lin、Didier Stien、Steven M. Weinreb
DOI:10.1021/ol990720e
日期:1999.8.1
[formula: see text] A mild new synthetic procedure has been developed for in situ generation and cyclization of iminylradicals onto pendant alkenes, followed by functionalization of the resulting carbon radical by one of a variety of trapping reagents. The key process in the method involves production of the iminylradical via treatment of an aldoxime or ketoxime with readily available 2,6-dimethylbenzenesulfinyl
Development of efficient new methodology for generation, cyclization and functional trapping of iminyl and amidyl radicals
作者:Xichen Lin、Gerald D. Artman、Didier Stien、Steven M. Weinreb
DOI:10.1016/s0040-4020(01)00878-x
日期:2001.10
New methodology has been devised for the generation and subsequent cyclization of iminyl and amidyl radicals under mild conditions. The process involves either the treatment of oximes with 2,6-dimethylbenzenesulfinyl chloride, or the treatment of hydroxamic acids with tert-butylsulfinyl chloride (-50 degreesC to rt), to give the corresponding nitrogen radicals, followed by cyclization onto pendant olefins. Radical traps such as diphenyl diselenide, diphenyl disulfide, and TEMPO can be used to terminate the cyclizations, thus introducing functionality that provides multiple options for further manipulation. In a more convenient procedure, both iminyl and amidyl radical cyclizations can be initiated using commercially available diethyl chlorophosphite which generally provides similar (with diphenyl disulfide and TEMPO) or significantly higher (with diphenyl diselenide) yields of products. (C) 2001 Elsevier Science Ltd. All rights reserved.