Alkynes react with organoborons under a CO atmosphere in the presence of a rhodium(I) catalyst to afford mainly 5-aryl-2(5H)-furanones, α,β-unsaturated ketones, and indanones. The product selectivity can be tuned by modifying the reaction conditions.
Asymmetric Synthesis of Triarylmethanes by Rhodium-Catalyzed Enantioselective Arylation of Diarylmethylamines with Arylboroxines
作者:Yinhua Huang、Tamio Hayashi
DOI:10.1021/jacs.5b03277
日期:2015.6.24
where Ar(1) is substituted with a 2-hydroxy group, with arylboroxines (Ar(3)BO)3 in the presence of a chiral diene-rhodium catalyst gave high yields of chiral triarylmethanes (Ar(1)Ar(2)CH*Ar(3)) with high enantioselectivity (up to 97% ee). The reaction is assumed to proceed through o-quinone methide intermediates which undergo Rh-catalyzed asymmetric 1,4-addition of the arylboron reagents.
Ligand- and Base-Free Pd(II)-Catalyzed Controlled Switching between Oxidative Heck and Conjugate Addition Reactions
作者:Sarah E. Walker、Julian Boehnke、Pauline E. Glen、Steven Levey、Lisa Patrick、James A. Jordan-Hore、Ai-Lan Lee
DOI:10.1021/ol400539h
日期:2013.4.19
solvent allows controlled and efficient switching between oxidative Heck and conjugateadditionreactions on cyclic Michael acceptor substrates, catalyzed by a cationic Pd(II) catalyst system. Both reactions are ligand- and base-free and tolerant of air and moisture, and the controlled switching sheds light on some of the factors which favor one reaction over the other.
Enantioselective Kinetic Resolution/Desymmetrization of
<i>Para</i>
‐Quinols: A Case Study in Boronic‐Acid‐Directed Phosphoric Acid Catalysis
作者:Banruo Huang、Ying He、Mark D. Levin、Jaime A. S. Coelho、Robert G. Bergman、F. Dean Toste
DOI:10.1002/adsc.201900816
日期:2020.1.23
A chiral phosphoric acid‐catalyzed kineticresolution and desymmetrization of para‐quinols operating via oxa‐Michael addition was developed and subsequently subjected to mechanistic study. Good to excellent s‐factors/enantioselectivities were obtained over a broad range of substrates. Kinetic studies were performed, and DFT studies favor a hydrogen bonding activation mode. The mechanistic studies provide
Rhodium(I)/Diene-Catalyzed Addition Reactions of Arylborons with Ketones
作者:Yuan-Xi Liao、Chun-Hui Xing、Qiao-Sheng Hu
DOI:10.1021/ol300275s
日期:2012.3.16
Rh(I)/diene-catalyzed additionreactions of arylboroxines/arylboronic acids with unactivated ketones to form tertiary alcohols in good to excellent yields are described. By using C2-symmetric (3aR,6aR)-3,6-diaryl-1,3a,4,6a-tetrahydropentalenes as ligands, the asymmetric version of such an additionreaction, with up to 68% ee, was also realized.
描述了 Rh(I)/二烯催化的芳基环硼氧烷/芳基硼酸与未活化酮形成叔醇的加成反应,收率很好。通过使用C 2 -对称 (3a R ,6a R )-3,6-二芳基-1,3a,4,6a-四氢戊烯作为配体,这种加成反应的不对称形式,具有高达 68% ee,也实现了。