Synthesis of<i>gem</i>-Difluoromethylene Building Blocks through Regioselective Allylation of<i>gem</i>-Difluorocyclopropanes
作者:Daisuke Munemori、Kent Narita、Toshiki Nokami、Toshiyuki Itoh
DOI:10.1021/ol500803r
日期:2014.5.16
derivatives react with allyltributylstannane in the presence of 2,2′-azobis(isobutyronitrile) to afford 1,6-dienes with a gem-difluoromethylene moiety at the allylic position. The reaction proceeds regioselectively with high yields, and the 1,6-dinenes obtained are good precursors for cyclic systems containing a gem-difluoromethylene moiety. Although S-methyl carbonodithioate also works as a leaving group
宝石-二氟环丙烷衍生物在2,2'-偶氮二(异丁腈)的存在下与烯丙基三丁基锡烷反应,得到在烯丙基位置具有宝石-二氟亚甲基部分的1,6-二烯。该反应以高产率进行区域选择性地进行,并且获得的1,6-二烯是含有宝石-二氟亚甲基部分的环状体系的良好前体。尽管S-甲基二硫代碳酸酯也用作离去基团,但是离去基团的重排与所需的烯丙基竞争,这取决于烯丙基三丁基锡烷的量。