作者:Rakesh Kumar、Barbara Zajc
DOI:10.1021/jo300971w
日期:2012.10.5
Julia–Kocienski reagents for the synthesis of fluoro enynes. Both reagents reacted with aldehydes under mild DBU- or LHMDS-mediated conditions, giving high yields of conjugated fluoro enynes with E-stereoselectivity. In comparison to DBU-mediated reactions, stereoselectivity was higher in low-temperature LHMDS-mediated reactions. Two ketones were shown to react as well, using LHMDS as base. In situ removal
TMS 和 TIPS 保护的 1,3-苯并噻唑-2-基 (BT) 炔丙基砜的金属化-亲电氟化得到相应的 BT 氟炔丙基砜,Julia-Kocienski 试剂用于合成氟烯炔。这两种试剂在温和的 DBU 或 LHMDS 介导的条件下与醛反应,产生具有E立体选择性的共轭氟烯炔的高产率。与 DBU 介导的反应相比,低温 LHMDS 介导的反应的立体选择性更高。两种酮也显示出反应,使用 LHMDS 作为碱。原位去除 TMS 基团得到末端共轭的 2-氟 1,3-烯炔。通过 Sonogashira 和 Heck 偶联转化为内部炔烃和立体异构氟二烯,证明了氟烯炔的合成效用。