College of Chemistry and Chemical Engineering, Central South University , Changsha 410083, People's Republic of China.
College of Chemistry and Materials Science, Guangxi Teachers Education University , Nanning, Guangxi 530001, People's Republic of China.
J Org Chem. 2017 Dec 1;82(23):12202-12208. doi: 10.1021/acs.joc.7b02064. Epub 2017 Nov 7.
With the aid of in situ protection by N-(2-formylphenyl)-4-methyl-benzenesulfonamide, enantioselective allylic alkylation of Morita-Baylis-Hillman carbonates with diethyl 2-aminomalonate was successfully realized. The corresponding adducts can be obtained in up to 99% yield with up to 98% ee as well as excellent regioselectivity. Besides, the adducts with opposite configurations were readily prepared by utilizing easily available and inexpensive quinine or quinidine as organocatalyst. Facile deprotection of the resulting adduct provides straightforward access to enantiopure α-methylene-γ-lactam.
在 N-(2-甲酰基苯基)-4-甲基苯磺酰胺的原位保护作用下,成功实现了 Morita-Baylis-Hillman 碳酸酯与二乙基 2-氨基丙二酸酯的对映选择性烯丙基烷基化反应。相应的加合物可以高达 99%的收率和高达 98%的对映选择性以及优异的区域选择性得到。此外,通过使用易得且廉价的奎宁或奎尼丁作为有机催化剂,很容易制备具有相反构型的加合物。得到的加合物的脱保护反应非常简便,可直接得到手性纯净的α-亚甲基-γ-内酰胺。