A C=O⋅⋅⋅Isothiouronium Interaction Dictates Enantiodiscrimination in Acylative Kinetic Resolutions of Tertiary Heterocyclic Alcohols
作者:Mark D. Greenhalgh、Samuel M. Smith、Daniel M. Walden、James E. Taylor、Zamira Brice、Emily R. T. Robinson、Charlene Fallan、David B. Cordes、Alexandra M. Z. Slawin、H. Camille Richardson、Markas A. Grove、Paul Ha‐Yeon Cheong、Andrew D. Smith
DOI:10.1002/anie.201712456
日期:2018.3.12
C=O⋅⋅⋅isothiouronium interaction as key to efficient enantiodiscrimination in the kineticresolution of tertiary heterocyclic alcohols bearing up to three potential recognition motifs at the stereogenic tertiary carbinol center. This discrimination was exploited in the isothiourea‐catalyzed acylative kineticresolution of tertiary heterocyclic alcohols (38 examples, s factors up to >200). The reaction proceeds at low
arylboronic acids to isatins. Asymmetric synthesis of 3‐aryl‐3‐hydroxy‐2‐oxindoles by 1,2‐addition of arylboronic acids to isatins was carried out in the presence of [RuCl2(PPh3)3]/(R,R)‐Me‐BIPAM and KF, resulting in an enantioselectivity as high as 90 % ee. It was found that the reaction with N‐protected isatins proceeds with high yields and good enantioselectivities. The best protective groups on the
Synthesis of a Class of Chiral-Bridged Phosphoramidite Ligands and Their Applications in the First Iridium-Catalyzed Asymmetric Addition of Arylboronic Acids to Isatins
A series of novel chiral phosphoramidite ligands based on chiral-bridged biphenyl backbones have been prepared conveniently and characterized. The ligands complexed with [IrCodCl](2) provided the first iridium catalyst system for the asymmetric addition of arylboronic acids to N-protected isatins with high efficiency. When performed in THF/H2O at 80 degrees C with 2 equiv of the arylboronic acids, the transformations acquired good to excellent results (up to 98% yield and 95% ee).
Rh(I)-catalyzed asymmetric 1,2-additions of arylboronic acids to isatins with chiral sulfur–alkene hybrid ligands
作者:Xiangqing Feng、Yanzhao Nie、Lanqiong Zhang、Jing Yang、Haifeng Du
DOI:10.1016/j.tetlet.2014.06.074
日期:2014.8
A rhodium-catalyzed asymmetric 1,2-addition of arylboronic acids to isatins with chiral sulfur-alkene hybrid ligands was achieved, and a variety of 3-aryl-3-hydroxy-2-oxindoles were obtained in moderate to good yields with up to 85% ee and a biologically active compound was synthesized with this strategy. (C) 2014 Elsevier Ltd. All rights reserved.
Rhodium-Catalyzed Asymmetric Addition of Aryl- and Alkenylboronic Acids to Isatins