We herein report a general, practical, and highly efficient method for asymmetricsynthesis of a wide range of chiral vicinal diamines via reductive coupling of imines templated by chiral diboron. The protocol features high enantioselectivity and stereospecificity, mild reaction conditions, simple operating procedures, use of readily available starting materials, and a broad substrate scope. The method
A dual-catalysis approach to the kinetic resolution of 1,2-diaryl-1,2-diaminoethanes
作者:Chang Min、Nisha Mittal、Chandra Kanta De、Daniel Seidel
DOI:10.1039/c2cc36361e
日期:——
The kinetic resolution of racemic C2-symmetric 1,2-diaryl-1,2-diaminoethanes was accomplished for the first time through application of a dual-catalysis approach.
Terminal fluoride ligands generate strong magnetic anisotropy in air-stable chiral dysprosium enantiomers supported by a bulky equatorial macrocycle, exhibiting a typical zero-field single-moleculemagnet behaviour.
Optical Resolution of (±)-1,2-Bis(2-methylphenyl)ethylene-1,2-diamine as a Chiral Framework for 2-Iminoimidazolidine with 2-Methylphenyl Pendant and the Guanidine-Catalyzed Asymmetric Michael Reaction of <i>tert</i>-Butyl Diphenyliminoacetate and Ethyl Acrylate
[GRAPHICS](+/-)-1,2-Bis(2-methylphenyl)ethylene-1,2-diamine, prepared from benzil and ammonium acetate, was optically resolved as a chiral framework for 2-(1-benzyl-2-hydroxyethyl)imino-1,3-dimethylimidazolidine with 2-methylphenyl pendants at the 4,5-positions. Catalysis ability of the 1,3-dimethyl-4,5-bis(2-methylphenyl)imidazolidine and the related 1,3-dibenzyl-4,5-diphenylimidazolidine was examined in the asymmetric Michael reaction of t-butyl diphenyliminoacetate and ethyl acrylate.
Convenient routes to vicinal diamines. Coupling of nitriles or N-(trimethylsilyl) imines promoted by NbCl4(THF)2