Zheng Ke, Shi Jian, Liu Xiaohua, Feng Xiaoming
Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, PR China.
J Am Chem Soc. 2008 Nov 26;130(47):15770-1. doi: 10.1021/ja808023y.
Highly enantioselective carbonyl-ene reaction of glyoxal derivatives and glyoxylate with various alkenes was accomplished using a novel nickel(II)-N,N'-dioxide complex under mild conditions, which facilitated the asymmetric synthesis of biologically interesting alpha-hydroxy carbonyl compounds. Various aromatic, aliphatic, and heteroaromatic glyoxal derivatives, as well as glyoxylate, could be tolerated in this system and afforded the corresponding adducts in excellent enantioselectivities (97->99% ee) with high yields. Moreover, the catalyst loading could even be decreased to 1 mol%, while the enantioselectivity was basically maintained.
在温和条件下，使用新型镍（II）-N，N'-二氧化物配合物实现了乙二醛衍生物和乙醛酸酯与各种烯烃的高度对映选择性羰基-烯反应，这促进了具有生物学意义的α-羟基羰基化合物的不对称合成。该体系中可以耐受各种芳香族、脂肪族和杂芳香族乙二醛衍生物以及乙醛酸酯，并以优异的对映选择性（97->99% ee）和高产率得到相应的加合物。此外，催化剂负载量甚至可以降低到1 mol%，而对映选择性基本保持不变。
