Synthesis of [2.2]paracyclophane-based bidentate oxazoline–carbene ligands for the asymmetric 1,2-silylation of N -tosylaldimines
摘要:
A series of novel oxazoline-substituted imidazolium salts with planar and central chirality has been successfully synthesized and applied to copper-catalyzed enantioselective 1,2-silylation of N-tosylaldimines. The oxazoline-carbene copper complex generated in situ by the reaction of the oxazoline-substituted imidazolium and Cu2O demonstrated an exceptionally high catalytic activity in the asymmetric 1,2-silylation of N-tosylaldimines, affording chiral alpha-amino silanes with excellent yields and enantioselectivities. (C) 2017 Elsevier Ltd. All rights reserved.
Enantioselective Addition of Silicon Nucleophiles to Aldimines Using a Preformed NHC-Copper(I) Complex as the Catalyst
作者:Alexander Hensel、Kazuhiko Nagura、Lukas B. Delvos、Martin Oestreich
DOI:10.1002/anie.201402086
日期:2014.5.5
asymmetric addition of siliconnucleophiles to typical prochiral acceptors, the enantioselective 1,2‐addition to aldimines, is addressed. Activation of the SiB bond in the silicon pronucleophile by a copper(I) alkoxide with McQuade’s chiral six‐membered N‐heterocyclic carbene as a supporting ligand releases the siliconnucleophile, which adds to various aldimines with high levels of enantioselectivity. The