Silver-catalyzed carbomagnesiation of terminal aryl and silyl alkynes and enynes in the presence of 1,2-dibromoethane
作者:Yuuki Fujii、Jun Terao、Nobuaki Kambe
DOI:10.1039/b820521c
日期:——
Regioselective carbomagnesiation of terminal alkynes and enynes with alkylGrignard reagents has been achieved by the combined use of a silver catalyst and 1,2-dibromoethane.
A combination of zinc metal and a catalytic amount of chlorotrimethylsilane has been found to promote the transformation of various aldehydes and ketones with gem-dichloro compounds, such as benzylidene dichloride (1a) and methyl dichloroacetate (1b), to the corresponding cross-coupling products, such as substituted styrene 3 and methyl acrylates 4 derivatives, under mild reaction conditions in THF. The E-isomer of the corresponding alkenes was obtained stereoselectively in good-to-excellent yields. The reaction serves as a very convenient one-pot procedure.
Iron-Catalyzed Alkylation of Alkenyl Grignard Reagents
作者:Gérard Cahiez、Christophe Duplais、Alban Moyeux
DOI:10.1021/ol7016092
日期:2007.8.1
The first iron-catalyzedcross-coupling reaction between alkenyl Grignard reagents and n- or s-alkyl bromides is described. The reaction is stereoselective and takes place in the presence of 5 mol % of [Fe(acac)3/TMEDA/HMTA] (1:2:1) under very mild conditions (THF, 0 degrees C, 45 min).