Switching Diastereoselectivity in Catalytic Enantioselective (3+2) Cycloadditions of Azomethine Ylides Promoted by Metal Salts and Privileged Segphos-Derived Ligands
作者:Guilherme S. Caleffi、Olatz Larrañaga、Marcos Ferrándiz-Saperas、Paulo R. R. Costa、Carmen Nájera、Abel de Cózar、Fernando P. Cossío、José M. Sansano
DOI:10.1021/acs.joc.9b00267
日期:2019.9.6
Catalytic enantioselective 1,3-dipolar cycloaddition between imino esters and electrophilic alkenes, employing chiral metal complexes derived from copper(I) and silver(I) salts and (S)-DM- or (S)-DTBM-Segphos as ligands produces diastereodivergently exo- or endo-cycloadducts, respectively. The effect of the functional group of the dipolarophile and the fine tuning of the catalyst plays an important
亚氨基酯与亲电子烯烃之间的催化对映选择性1,3-偶极环加成反应,采用衍生自铜(I)和银(I)盐和(S)-DM-或(S)-DTBM-Segphos的手性金属络合物作为配体,可产生非对映异构体分别是环外加合物或环内加合物。亲双极性体的官能团的作用和催化剂的微调在促进反向非对映选择性中起重要作用。还通过密度泛函理论计算来解释实验观察到的对映选择性和非对映选择性数据的起源,以及观察到的转换的内/外比的起源。