报道了立体发散的不对称路易斯碱催化烯酮酸的迈克尔加成/内酯化成取代的二氢苯并呋喃和四氢呋喃衍生物。市售的 ( S )-(-)-四咪唑盐酸盐可提供具有高顺非对映选择性和出色对映选择性的产品(高达 99:1 dr syn / anti,99 % ee syn),而使用金鸡纳生物碱衍生的催化剂可得到相应的反-主要产品为非对映异构体(高达 10:90 dr syn / anti , 99 % ee anti)。
报道了立体发散的不对称路易斯碱催化烯酮酸的迈克尔加成/内酯化成取代的二氢苯并呋喃和四氢呋喃衍生物。市售的 ( S )-(-)-四咪唑盐酸盐可提供具有高顺非对映选择性和出色对映选择性的产品(高达 99:1 dr syn / anti,99 % ee syn),而使用金鸡纳生物碱衍生的催化剂可得到相应的反-主要产品为非对映异构体(高达 10:90 dr syn / anti , 99 % ee anti)。
Organocatalytic Functionalization of Carboxylic Acids: Isothiourea-Catalyzed Asymmetric Intra- and Intermolecular Michael Addition−Lactonizations
作者:Dorine Belmessieri、Louis C. Morrill、Carmen Simal、Alexandra M. Z. Slawin、Andrew D. Smith
DOI:10.1021/ja109975c
日期:2011.3.2
Tetramisole promotes the catalytic asymmetric intramolecular Michael addition-lactonization of a variety of enone acids, giving carbo- and heterocyclic products with high diastereo- and enantiocontrol (up to 99:1 dr, up to 99% ee) that are readily derivatized to afford functionalized indene and dihydrobenzofuran carboxylates. Chiral isothioureas also promote the catalytic asymmetric intermolecular Michael addition-lactonization of arylacetic acids and alpha-keto-beta,gamma,-unsaturated esters, giving anti-dihydropyranones with high diastereo- and enantiocontrol (up to 98:2 dr, up to 99% ee).