Synthesis of Chiral Diamine Ligands for Nickel-catalyzed Asymmetric Cross-couplings of Alkylchloroboronate Esters with Alkylzincs: (1R,2R)-N,N’-Dimethyl-1,2-bis(2-methylphenyl)-1,2-diaminoethane
Design of Ru(II)-NHC-Diamine Precatalysts Directed by Ligand Cooperation: Applications and Mechanistic Investigations for Asymmetric Hydrogenation
作者:Wei Li、Tobias Wagener、Lars Hellmann、Constantin G. Daniliuc、Christian Mück-Lichtenfeld、Johannes Neugebauer、Frank Glorius
DOI:10.1021/jacs.0c00985
日期:2020.4.15
A modular synthesis of Ru(II)-NHC-diamine complexes from readily available chiral N-heterocyclic carbenes (NHCs) and chiraldiamines is disclosed for the first time. The well-defined Ru(II)-NHC-diamine complexes show unique structure and coordination chemistry including an unusual tridentate coordination effect of 1,2-diphenylethylenediamine. The isolated air- and moisture-stable Ru(II)-NHC-diamine
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
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.