Selective Mono- and 1,2-Difunctionalisation of Cyclopentene Derivatives via Mg and Cu Intermediates
作者:Christina Despotopoulou、Richard C. Bauer、Arkady Krasovskiy、Peter Mayer、Jeffrey M. Stryker、Paul Knochel
DOI:10.1002/chem.200701431
日期:2008.3.7
A single Br/Mg exchange of 1,2-dibromocyclopentene with iPrMgCl LiCl provides the corresponding beta-bromocyclopentenylmagnesium reagent, which can then be reacted with various electrophiles (yields: 65-82 %). In the presence of a secondary alkylmagnesium halide and Li2CuCl4 (2 mol %), these 2-bromoalkenylmagnesium compounds undergo bromine substitution and can then further react with electrophiles
1,2-二溴环戊烯与iPrMgCl LiCl的一次Br / Mg交换提供了相应的β-溴环戊烯基镁试剂,然后可以使其与各种亲电试剂反应(收率:65-82%)。在仲烷基卤化镁和Li 2 CuCl 4(2mol%)的存在下,这些2-溴烯基镁化合物进行溴取代,然后可以进一步与亲电试剂反应,得到1,2-二官能化的环戊烯(63-79%)。讨论了此过程的机制。