chiral Rh and Rh/Ag bimetallic nanoparticle catalysts consisting of polystyrene-based polymers with chiral diene moieties. The catalysts enable high-to-excellent yields and enantioselectivities to be obtained in asymmetric 1,4-addition reactions of arylboronic acids with α,β-unsaturated carbonyl compounds such as ketones, esters, and amides, and in other asymmetric reactions. The catalysts could be readily
Rhodium-catalyzed Asymmetric Arylation of Nitroalkenes Powered by Simple Chiral Sulfur-Olefin Ligands
作者:Zheng Wang、Wen-Wen Chen、Ming-Hua Xu
DOI:10.1002/jccs.201700328
日期:2018.3
An efficient rhodium‐catalyzed enantioselective addition of potassium organotrifluoroborates to nitroalkenes powered by simple chiral sulfur‐olefin ligands is reported. This protocol is applicable to a broad range of 2‐aryl‐, alkyl‐, and heteroaryl‐substituted nitroalkenes, allowing access to diverse chiral β,β‐disubstituted nitroethanes in good to excellent yields with high enantioselectivity under
Rhodium-Catalyzed Asymmetric Conjugate Addition of Organoboronic Acids to Nitroalkenes Using Chiral Bicyclo[3.3.0] Diene Ligands
作者:Zhi-Qian Wang、Chen-Guo Feng、Shu-Sheng Zhang、Ming-Hua Xu、Guo-Qiang Lin
DOI:10.1002/anie.201001883
日期:——
Old before I diene: An efficient rhodium/diene‐catalyzed asymmetricconjugateaddition of organoboronic acids to challenging nitroalkene substrates that lack α substituents has been developed. Chiral bicyclo[3.3.0] dienes were found to be superior ligands under ArB(OH)2/KHF2 conditions. Np=naphthyl.
A Scalable Synthesis of Chiral Himbert Diene Ligands for Asymmetric Catalysis
作者:Raja K. Rit、Hongyi Li、Stephen P. Argent、Katherine M. Wheelhouse、Simon Woodward、Hon Wai Lam
DOI:10.1002/adsc.202300039
日期:——
Chiral dienes are important ligands in asymmetriccatalysis but they are less accessible than other commonly used ligands such as chiral bisphosphines. Here, we show that intramolecular [4+2] cycloaddition of a simply attained chiral allenecarboxanilide readily affords pseudoenantiomeric bicyclo[2.2.2]octa-2,5-dienes containing an alkenyl bromide, which can be readily functionalized to give diverse