Direct Synthesis of Enolizable<i>N</i>-Sulfonyl Ketimines Under Microwave Irradiation
作者:Pablo Ortiz、Juan F. Collados、Syuzanna R. Harutyunyan
DOI:10.1002/ejoc.201600022
日期:2016.3
through direct condensation between the parent aldehyde and the sulfonamide. However, this approach is not efficient for the synthesis of enolizable N-sulfonyl ketimines. Herein we report a rapid and facile methodology for obtaining these products using microwaveirradiation.
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
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
application of ketone‐derived oxaziridines as alkyl radical precursors in copper‐catalyzed Carbon‐Carbonbondformation reactions. Experimental and computational studies indicate a free radical mechanism, where alkyl radicals are efficiently generated via cleavage of a Carbon‐Carbonbond of oxaziridines. Acyclic and unstrained cyclic oxaziridines are applicable to the present radical process, allowing
A rhodium-catalyzed addition of sodium tetraarylborates to N-tosyl ketimines is described. Highly efficient asymmetric catalysis has been achieved by employing a chiral diene ligand, constructing chiral amine derivatives possessing alpha-tetrasubstituted carbon stereocenters with high enantioselectivity.