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
importance. An attractive strategy is the arylation of imines with organoboronreagents. Chiral Rh complexes have reached a high level of productivity for this reaction type. In this article we describe that an electron rich PdII catalyst also performs well in the arylation of aldimines, comparable to the best Rh catalysts. The ferrocenyl palladacycle‐acetate catalyst allows for a broad substrate scope and
Exogenous-Base-Free Palladacycle-Catalyzed Highly Enantioselective Arylation of Imines with Arylboroxines
作者:Carmen Schrapel、René Peters
DOI:10.1002/anie.201501846
日期:2015.8.24
Enantiomerically pure benzylic amines are important for the development of new drugs. A readily accessible planar‐chiralferrocene‐derived palladacycle is shown to be a highly efficient catalyst for the formation of N‐substituted benzylic stereocenters; this catalyst accelerates the 1,2‐addition of arylboroxines to aromatic and aliphatic imines with exceptional levels of enantioselectivity. Using aldimines
Catalytic Enantioselective Arylation of <i>N</i>-Tosylarylimines with Arylboronic Acids Using <i>C</i><sub>2</sub>-Symmetric Cationic <i>N</i>-Heterocyclic Carbene Pd<sup>2+</sup> Diaquo Complexes
作者:Guang-Ning Ma、Tao Zhang、Min Shi
DOI:10.1021/ol802861s
日期:2009.2.19
The asymmetric arylation of N-tosylimines with arylboronic acids was realized by using chiral cationic C-2-symmetric N-heterocyclic carbene (NHC) Pd2+ diaquo complex 5b as the catalyst in combination with 1.0 equiv of K3PO4 center dot 3H(2)O in THF at 4 degrees C in the presence of powdered 4 angstrom MS to afford the corresponding adducts in excellent yields (up to 99%) and good to high enantioselectivities (up to 94% ee).
Asymmetric Stepwise Reductive Amination of Sulfonamides, Sulfamates, and a Phosphinamide by Nickel Catalysis
作者:Xiaohu Zhao、Haiyan Xu、Xiaolei Huang、Jianrong Steve Zhou
DOI:10.1002/anie.201809930
日期:2019.1.2
Asymmetricreductive amination of poorly nucleophilic sulfonamides was realized in the presence of nickel catalysts and titanium alkoxide. A wide range of ketones, including enolizable ketones and some biaryl ones, were converted into sulfonamides in excellent enantiomeric excess. The cyclization of sulfamates and intermolecular reductive amination of a diarylphosphinamide were also successful. Formic