Intermolecular C–H functionalization versus cyclopropanation of electron rich 1,1-disubstituted and trisubstituted alkenes
作者:Dominic L. Ventura、Zhanjie Li、Michael G. Coleman、Huw M.L. Davies
DOI:10.1016/j.tet.2008.11.059
日期:2009.4
Rhodium(II)-catalyzed reactions of aryldiazoacetates with electron rich 1,1-disubstituted and trisubstituted alkenes were systematically studied. The regio-, diastereo- and enantioselectivity of the chemistry was profoundly influenced by the nature of the substrates and the catalyst. Conditions were developed for either selective cyclopropanation or C–H insertion. Both reactions can be achieved with
系统研究了铑(II)催化重氮乙酸芳基酯与富电子的1,1-二取代和三取代烯烃的反应。化学的区域,非对映和对映选择性受到底物和催化剂性质的深刻影响。为选择性环丙烷化或CH插入开发了条件。两种反应都可以实现高非对映选择性和对映选择性(对于C–H插入:> 90%de,最高96%ee,对于环丙烷化:> 94%de,最高95%ee)。对于1,1-二取代的乙烯基醚,环丙烷化的非对映选择性是可变的,但在优化的系统中,环丙烷的de> 94%,ee最高可达98%。