Enantioselective glyoxylate-ene reactions catalysed by (salen)chromium(III) complexes
作者:Wojciech Chaładaj、Piotr Kwiatkowski、Jakub Majer、Janusz Jurczak
DOI:10.1016/j.tetlet.2007.01.104
日期:2007.3
enantioselective carbonyl-ene reaction of alkyl glyoxylates with various 1,1-disubstituted olefins, catalysed by chiral (salen)Cr(III)BF4 complexes, has been studied. We found that a chromium complex bearing adamantyl substituents at the 3,3′-positions of the salicylidene moiety catalysed the reaction with much greater selectively than the classic Jacobsen-type catalyst. The reaction proceeded effectively
研究了手性(salen)Cr(III)BF 4配合物催化的乙醛酸烷基酯与各种1,1-二取代烯烃的对映选择性羰基-烯反应。我们发现,在水杨叉基部分的3,3'-位置带有金刚烷基取代基的铬络合物催化反应的选择性要比经典的雅各布森型催化剂高得多。在2 mol%的催化剂存在下,在可接受的收率和59-92%ee的条件下,反应可在不苛刻的条件下有效地进行。