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
Chiral N-Heterocyclic Carbene Ligands Bearing a Pyridine Moiety for the Copper-Catalyzed Alkylation of<i>N</i>-Sulfonylimines with Dialkylzinc Reagents
Amino acid‐derived chiral imidazolium salts, each bearing a pyridine ring, were developed as N‐heterocyclic carbeneligands. The copper‐catalyzed asymmetric alkylation of various N‐sulfonylimines with dialkylzincreagents in the presence of these chiral imidazolium salts afforded the corresponding alkylated products with high enantioselectivity (up to 99 % ee). The addition of HMPA to the reaction
Cinchona-Derived Picolinamides: Effective Organocatalysts for Stereoselective Imine Hydrosilylation
作者:Pedro C. Barrulas、Andrea Genoni、Maurizio Benaglia、Anthony J. Burke
DOI:10.1002/ejoc.201403180
日期:2014.11
Picolinamide–cinchona organocatalysts for the successful enantioselective reduction of ketomines were developed. For the first time, a new type of chiral Lewis base, a cationic species, is reported to efficiently organocatalyze the addition of trichlorosilane to imines. Excellent yields with good to high enantioselectivities (up to 91 %) were obtained in the reduction of differently substituted substrates
Rhodium-Catalyzed Enantioselective Arylation of Aliphatic Imines
作者:Naoya Kato、Tomohiko Shirai、Yasunori Yamamoto
DOI:10.1002/chem.201601246
日期:2016.6.1
Chiral rhodium(I)‐catalyzed highly enantioselective arylation of aliphatic N‐sulfonyl aldimines with arylboronic acids has been developed. This transformation is achieved by the use of a rhodium/bis(phosphoramidite) catalyst to give enantiomerically enriched α‐branched amines (up to 99 % ee). In addition, this system enables efficient synthesis of (+)‐NPS R‐568 and Cinacalcet which are calcimimetic
Nickel-Catalyzed Asymmetric Transfer Hydrogenation and α-Selective Deuteration of <i>N</i>-Sulfonyl Imines with Alcohols: Access to α-Deuterated Chiral Amines
A nickel-catalyzed enantioselective transferhydrogenation and deuteration of N-sulfonyl imines was developed. Excellent α-selectivity and high deuterium content were achieved by using inexpensive 2-propanol-d8 as a deuterium source. As a highlight, no deuteration of β-C–H and the remote C–H of N-sulfonyl amines occurred, which is hard to achieve using other imines or by hydrogen isotope exchange with