Synthesis of Axially Chiral 2,2′-Bisphosphobiarenes via a Nickel-Catalyzed Asymmetric Ullmann Coupling: General Access to Privileged Chiral Ligands without Optical Resolution
作者:Ziqing Zuo、Raphael S. Kim、Donald A. Watson
DOI:10.1021/jacs.0c12843
日期:2021.1.27
We report an asymmetric homocoupling of ortho-(iodo)arylphosphine oxides and ortho-(iodo)arylphosphonates resulting in highly enantioenriched axially chiral bisphosphine oxides and bisphosphonates. These products are readily converted to enantioenriched biaryl bisphosphines without need for chiralauxiliaries or optical resolution. This provides a practical route for the development of previously uninvestigated
A new and convenient method for investigating the relationship between the position of the enantiodetermining sites in chiral phosphine ligands and enantioselectivity in asymmetric hydrogenation is proposed. We have also synthesized four new diphosphine ligands, some of which give high enantioselectivity in the asymmetric hydrogenation of an enamide. (C) 2004 Elsevier Ltd. All rights reserved.
Iridium-Catalyzed Oxidative Olefination of Furans with Unactivated Alkenes
作者:Christo S. Sevov、John F. Hartwig
DOI:10.1021/ja504414c
日期:2014.7.30
The oxidative coupling of arenes and alkenes is an attractive strategy for the synthesis of vinylarenes, but reactions with unactivatedalkenes have typically occurred in low yield. We report an Ir-catalyzed oxidative coupling of furans with unactivated olefins to generate branched vinylfuran products in high yields and with high selectivities with a second alkene as the hydrogen acceptor. Detailed
芳烃和烯烃的氧化偶联是合成乙烯基芳烃的一种有吸引力的策略,但与未活化烯烃的反应通常以低产率发生。我们报告了呋喃与未活化烯烃的 Ir 催化氧化偶联,以高产率和高选择性生成支链乙烯基呋喃产物,第二个烯烃作为氢受体。详细的机械实验揭示了催化剂分解途径,这些途径通过明智地选择反应条件和应用新配体而得到缓解。