Enantioselective Synthesis of Homoallylic Amines through Reactions of (Pinacolato)allylborons with Aryl-, Heteroaryl-, Alkyl-, or Alkene-Substituted Aldimines Catalyzed by Chiral C1-Symmetric NHC−Cu Complexes
- 22 February 2011
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 133 (10), 3332-3335
- https://doi.org/10.1021/ja200311n
Abstract
A catalytic method for enantioselective synthesis of homoallylamides through Cu-catalyzed reactions of stable and easily accessible (pinacolato)allylborons with aryl-, heteroaryl-, alkyl-, or alkenyl-substituted N-phosphinoylimines is disclosed. Transformations are promoted by 1−5 mol % of readily accessible NHC−Cu complexes, derived from C1-symmetric imidazolinium salts, which can be prepared in multigram quantities in four steps from commercially available materials. Allyl additions deliver the desired products in up to quantitative yield and 98.5:1.5 enantiomeric ratio and are amenable to gram-scale operations. A mechanistic model accounting for the observed selectivity levels and trends is proposed.This publication has 55 references indexed in Scilit:
- Enantioselective Synthesis of Boron-Substituted Quaternary Carbons by NHC−Cu-Catalyzed Boronate Conjugate Additions to Unsaturated Carboxylic Esters, Ketones, or ThioestersJournal of the American Chemical Society, 2010
- Enantioselective Synthesis of Allylboronates Bearing a Tertiary or Quaternary B-Substituted Stereogenic Carbon by NHC-Cu-Catalyzed Substitution ReactionsJournal of the American Chemical Society, 2010
- Diastereoselective Access to Enantiomerically Pure cis‐2,3‐Disubstituted PyrrolidinesEuropean Journal of Organic Chemistry, 2010
- Enantioselective Conjugate Silyl Additions to Cyclic and Acyclic Unsaturated Carbonyls Catalyzed by Cu Complexes of Chiral N-Heterocyclic CarbenesJournal of the American Chemical Society, 2010
- Enantioselective Ag‐Catalyzed Allylation of AldiminesEuropean Journal of Organic Chemistry, 2009
- Stereogenic-at-Metal Zn- and Al-Based N-Heterocyclic Carbene (NHC) Complexes as Bifunctional Catalysts in Cu-Free Enantioselective Allylic AlkylationsJournal of the American Chemical Society, 2009
- Efficient C−B Bond Formation Promoted by N-Heterocyclic Carbenes: Synthesis of Tertiary and Quaternary B-Substituted Carbons through Metal-Free Catalytic Boron Conjugate Additions to Cyclic and Acyclic α,β-Unsaturated CarbonylsJournal of the American Chemical Society, 2009
- Efficient Boron−Copper Additions to Aryl-Substituted Alkenes Promoted by NHC−Based Catalysts. Enantioselective Cu-Catalyzed Hydroboration ReactionsJournal of the American Chemical Society, 2009
- Asymmetric Synthesis of Homoallylic Amines Bearing Adjacent Stereogenic Centers by Addition of Substituted Allylic Zinc Reagents to N-tert-ButanesulfinyliminesOrganic Letters, 2008
- Asymmetric Allylboration of Acyl Imines Catalyzed by Chiral DiolsJournal of the American Chemical Society, 2007