Chelation and Stereodirecting Group Effects on Regio- and Diastereoselective Samarium(II)-Water Allylic Benzoate Reductions
作者:Gregory W. O’Neil、Trevor F. Stockdale、Michael A. Leitch
DOI:10.1055/s-0039-1690826
日期:2020.5
SmI2(H2O)n reductions of allylic benzoates adjacent to a trisubstituted alkene occur in high yields with complete regioselectivity and good diastereoselectivity (up to 90:10) for substrates containing properly positioned stereodirecting- and chelating groups. The outcome of these reactions can be rationalized by ring conformation considerations of a proposed chelated organosamarium intermediate, and
对于含有正确定位的立体定向和螯合基团的底物,与三取代的烯烃相邻的烯丙基苯甲酸酯的SmI 2(H 2 O)n还原反应具有很高的产率,具有完全的区域选择性和良好的非对映选择性(高达90:10)。这些反应的结果可以通过提出的螯合有机ring中间体的环构象考量和涉及-结合水的分子内质子化的机理来合理化。