Base-Catalyzed Reactivity of Sulfur- and Selenium-Bridged Cyclic Alkynes: Tandem Isomerization and Cycloaromatization versus Isomerization and Nucleophilic Addition
作者:Samuel Braverman、Marina Cherkinsky、Mihail L. Birsa、Yossi Zafrani
DOI:10.1002/1099-0690(200209)2002:18<3198::aid-ejoc3198>3.0.co;2-c
日期:2002.9
The synthesis and base-catalyzed reactivity of some novel sulfur- and selenium-bridged cyclic di- and tetralkynes, derived from 1,2- and 1,4-dihydroxybenzene and 1,2-bis(bromomethyl)benzene, are described. The cyclic propargylic sulfides and selenides undergo base-induced isomerization to the corresponding allenes, followed by cycloaromatization of the latter by diradical or anionic mechanisms, depending
描述了一些新型硫-和硒-桥连的环状二和四炔烃的合成和碱催化反应,它们源自 1,2-和 1,4-二羟基苯以及 1,2-双(溴甲基)苯。环状炔丙基硫化物和硒化物经过碱诱导异构化成相应的丙二烯,然后通过双自由基或阴离子机制将后者环芳构化,这取决于碱的性质。由于预期的双自由基中间体缺乏稳定性,相应的丙二烯砜会发生亲核加成,这是其 DNA 切割特性的原因。(© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)