Enantioselective synthesis of Benzofurans bearing adjacent quaternary and tertiary carbon stereocenters by Organocatalytic asymmetric Michael addition of 3-methylbenzofuran −2(3H)-ones to azadienes
An enantioselective Michael addition of 3-methylbenzofuran-2(3H)-ones to azadienes catalyzed by an L-tert- leucine derived squaramide catalyst was developed, by which a variety of benzofuranones bearing adjacentquaternary and tertiary carbon centers were obtained in high yields (up to 98%) with moderate to excellent diastereoselectivities (up to 97:3) and enantioselectivities (up to 97%).
An enantioselective Mannich reaction of N-Boc aminosulfones with 3-methylbenzofuran-2 (3H)-ones catalyzed by a quinine-derived bifunctional phase transfer catalyst was developed, by which a series of chiral benzofuranones bearing adjacent quaternary and tertiary carbon centers were obtained in high yields (up to 96%) with good diastereoselectivities (up to >99:1) and enantioselectivities (up to 98%)
开发了由奎宁衍生的双功能相转移催化剂催化的 N -Boc 氨基砜与 3-甲基苯并呋喃-2 (3H)-酮的对映选择性曼尼希反应,通过该反应获得了一系列带有相邻季碳和叔碳中心的手性苯并呋喃酮高产率(高达 96%),具有良好的非对映选择性(高达 >99:1)和对映选择性(高达 98%)。
UTILISATION DE DIHYDROBENZOFURANONES A TITRE D'INGREDIENTS PARFUMANTS
申请人:FIRMENICH SA
公开号:EP0707575B1
公开(公告)日:2001-10-24
Enantioselective Black rearrangement catalyzed by chiral bicyclic imidazole
A newly developed chiral imidazole nucleophilic catalyst, Acyloxy-DPI, was readily prepared and successfully applied to the enantioselective Black rearrangement with up to 88% ee for a wide range of substrates possessing different substituted groups. A plausible mechanism for the high enantioselectivity was proposed.