Asymmetric Michael addition of formaldehyde N,N-dialkylhydrazones to alkylidene malonates
作者:Juan Vázquez、Auxiliadora Prieto、Rosario Fernández、Dieter Enders、José M. Lassaletta
DOI:10.1039/b200209b
日期:——
Enantiopure formaldehydeN,N-dialkylhydrazones 1 smoothly react with prochiral alkylidene malonates 2 in the presence of MgI2 to afford the corresponding Michael adducts 3 in excellent yields and good diastereoselectivities; direct racemization-free BF3.OEt2-catalyzed thiolysis of the hydrazone C=N bond affords the corresponding dithioketals 7 in optically pure or enantiomerically enriched form.
在MgI 2的存在下,对映纯甲醛N,N-二烷基hydr盐1与手性亚烷基丙二酸酯2平滑反应,以优异的收率和良好的非对映选择性提供相应的迈克尔加合物3。race C = N键的无外消旋的直接BF3.OEt2催化硫解得到了相应的光学纯或对映体富集形式的二硫缩酮7。