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
A Mild Synthesis of Vinyl Halides and <i>gem</i>-Dihalides Using Triphenyl Phosphite−Halogen-Based Reagents
作者:Alberto Spaggiari、Daniele Vaccari、Paolo Davoli、Giovanni Torre、Fabio Prati
DOI:10.1021/jo061346g
日期:2007.3.1
A new application of (PhO)(3)P-halogen-based reagents to the synthesis of vinyl halides and gem-dihalides is described. Vinyl halides were prepared in good to excellent yields from enolizable ketones, whereas aldehydes afforded the corresponding gem-dihalides. The halogenation proceeded smoothly under mild conditions.