Catalytic asymmetric epoxidation of α,β-unsaturated carboxylic acid imidazolides and amides by lanthanide–BINOL complexes
作者:Takashi Ohshima、Tetsuhiro Nemoto、Shin-ya Tosaki、Hiroyuki Kakei、Vijay Gnanadesikan、Masakatsu Shibasaki
DOI:10.1016/j.tet.2003.06.010
日期:2003.12
Highly enantioselective catalytic asymmetric epoxidation of α,β-unsaturated carboxylic acid imidazolides and simple amides was developed. In the presence of 5–10 mol% of lanthanide–BINOL complexes, the reaction proceeded smoothly with high substrate generality. In particular, in the cases of α,β-unsaturated amides, there was nearly perfect enantioselectivity (>99% ee). The corresponding epoxides were
研究了α,β-不饱和羧酸咪唑化物和简单酰胺的高度对映选择性催化不对称环氧化反应。在5-10 mol%的镧系元素-BINOL配合物的存在下,反应在高底物普遍性下可顺利进行。特别地,在α,β-不饱和酰胺的情况下,几乎具有完美的对映选择性(> 99%ee)。相应的环氧化物已成功转化为多种类型的有用手性化合物,例如α,β-环氧酯,α,β-环氧酰胺,α,β-环氧醛,α,β-环氧β-酮酸酯,α-和β-羟基羰基化合物。进行B3LYP密度泛函研究以预测底物反应性。