A Chiral Chelating Diene as a New Type of Chiral Ligand for Transition Metal Catalysts: Its Preparation and Use for the Rhodium-Catalyzed Asymmetric 1,4-Addition
摘要:
As a new type of chiral ligand, a C2-symmetric norbornadiene derivative (1R,4R)-2,5-dibenzylbicyclo[2.2.1]hepta-2,5-diene (1) was prepared and used for the rhodium-catalyzed asymmetric addition of organoboron and -tin reagents to alpha,beta-unsaturated ketones, which gave high yields of the 1,4-addition products with up to 99% enantioselectivity.
A Chiral Chelating Diene as a New Type of Chiral Ligand for Transition Metal Catalysts: Its Preparation and Use for the Rhodium-Catalyzed Asymmetric 1,4-Addition
摘要:
As a new type of chiral ligand, a C2-symmetric norbornadiene derivative (1R,4R)-2,5-dibenzylbicyclo[2.2.1]hepta-2,5-diene (1) was prepared and used for the rhodium-catalyzed asymmetric addition of organoboron and -tin reagents to alpha,beta-unsaturated ketones, which gave high yields of the 1,4-addition products with up to 99% enantioselectivity.
A Chiral Chelating Diene as a New Type of Chiral Ligand for Transition Metal Catalysts: Its Preparation and Use for the Rhodium-Catalyzed Asymmetric 1,4-Addition
摘要:
As a new type of chiral ligand, a C2-symmetric norbornadiene derivative (1R,4R)-2,5-dibenzylbicyclo[2.2.1]hepta-2,5-diene (1) was prepared and used for the rhodium-catalyzed asymmetric addition of organoboron and -tin reagents to alpha,beta-unsaturated ketones, which gave high yields of the 1,4-addition products with up to 99% enantioselectivity.
Expanding the <i>C</i><sub>2</sub>-Symmetric Bicyclo[2.2.1]hepta-2,5-diene Ligand Family: Concise Synthesis and Catalytic Activity in Rhodium-Catalyzed Asymmetric Addition
作者:Guillaume Berthon-Gelloz、Tamio Hayashi
DOI:10.1021/jo061385s
日期:2006.11.1
achieved through the formation of the corresponding stable [RhCl(diene)]2 complexes. These chiral rhodium complexes displayed high activity and enantioselectivity (up to 99% ee) in the rhodium-catalyzed 1,4-addition and 1,2-addition of phenylboronic acid to cyclicenones and N-sulfonylimines, respectively.
The Diels-Alder reaction, which is a traditional [4 + 2] cycloaddition with two carbon-carbon bond formations, is one of the most powerful tools to synthesize versatile and unique six-membered rings. We show that chiral supramolecular U-shaped boron Lewisacid catalysts promote the unprecedented multiselective Diels-Alder reaction of propargyl aldehyde with cyclic dienes. Independent from the substrate
Diels-Alder 反应是一种传统的 [4 + 2] 环加成反应,具有两个碳-碳键形成,是合成通用且独特的六元环的最强大工具之一。我们表明手性超分子 U 形硼路易斯酸催化剂促进了炔丙醛与环二烯前所未有的多选择性 Diels-Alder 反应。独立于底物控制,对映-、内/外-、π-面-、区域-、位点和底物选择性可以通过本 U 形催化剂进行控制。所得反应产物可用于手性二烯配体和(+)-沙霉素关键中间体的简明合成。这里介绍的结果可能部分有助于开发用于多选择性反应的人工酶样超分子催化剂,
A Chiral Chelating Diene as a New Type of Chiral Ligand for Transition Metal Catalysts: Its Preparation and Use for the Rhodium-Catalyzed Asymmetric 1,4-Addition
作者:Tamio Hayashi、Kazuhito Ueyama、Norihito Tokunaga、Kazuhiro Yoshida
DOI:10.1021/ja037367z
日期:2003.9.1
As a new type of chiral ligand, a C2-symmetric norbornadiene derivative (1R,4R)-2,5-dibenzylbicyclo[2.2.1]hepta-2,5-diene (1) was prepared and used for the rhodium-catalyzed asymmetric addition of organoboron and -tin reagents to alpha,beta-unsaturated ketones, which gave high yields of the 1,4-addition products with up to 99% enantioselectivity.