Allylboration of Ketones and Imines with a Highly Reactive Bifunctional Allyl Pinacolatoboronate Reagent
作者:Jiaming Liu、Xinbo Tong、Ming Chen
DOI:10.1021/acs.joc.9b03222
日期:2020.4.17
Allylboration of ketones and imines with a bifunctional allylboron reagent is reported. Addition of the bifunctional allylboronate to a broad scope of ketones gave tertiary alcohols in excellent yields at ambient temperature without any catalyst or additive. Allylboration of cyclic aldimines also proceeded to give allylated products in good yields under the same reaction conditions. The allylsilane
Spiro indane-based phosphine–oxazoline ligands for palladium-catalyzed asymmetric arylation of cyclic N-sulfonyl imines
作者:Zhongxuan Qiu、Yanshun Li、Zhenqing Zhang、Dawei Teng
DOI:10.1007/s11243-019-00329-z
日期:2019.10
Palladium complexes of indane-based phosphine–oxazoline ligands with a spirocarbon stereogenic center were examined for asymmetric addition of arylboronic acids to cyclic N-sulfonyl imines. Excellent reaction activities (up to 99% yield) and enantioselectivities (up to 99% ee) were obtained with a broad scope of substrate.
A series of chiral phosphine‐imine ligands were synthesized starting with α‐amino acids and examined for palladium‐catalyzed asymmetric addition of arylboronic acids to cyclic N‐sulfonylimines. High catalytic activities (up to 99% yield) and high enantioselectivities (up to 98% ee) were achieved for cyclic N‐sulfonyl aldimines and ketimines with five and six‐membered ring structures.
Rhodium-Catalyzed Asymmetric Addition of Organoboronic Acids to Aldimines Using Chiral Spiro Monophosphite-Olefin Ligands: Method Development and Mechanistic Studies
作者:Huanyu Shan、Qiaoxia Zhou、Jinglu Yu、Shuoqing Zhang、Xin Hong、Xufeng Lin
DOI:10.1021/acs.joc.8b01764
日期:2018.10.5
on a hexamethyl-1,1′-spirobiindane scaffold was accomplished starting from Bisphenol C. The optimal ligand could serve as an elegant chiral bidentate ligand in the Rh-catalyzed asymmetric 1,2-addition of organoboronic acids to various acyclic/cyclic aldimines, leading to chiral amines with high yields and excellent enantioselectivities. Detailed stereochemical models for enantioselective induction
Abstract Disclosed herein is a photochemical organocatalytic strategy for the direct enantioselective Mannich-type reaction of 2-alkylbenzophenones and cyclicimines. The chemistry exploits the light-triggered enolization of 2-alkylbenzophenones to generate transient hydroxy-o-quinodimethanes. These fleeting intermediates can be stereoselectively intercepted by imines upon activation with a chiral organic