The preparation of new enantiopure imidazolinium salts and their evaluation as catalysts and shift reagents
摘要:
A series of new chiral imidazolinium salts were prepared and tested as catalysts. It was possible to show that bis-imidazolinium salts had a higher reactivity than mono-imidazolium salts. In addition a chiral discrimination of the bis-imidazolinium salts with the potassium salt of racemic Mosher's acid wits proven by NMR studies. (c) 2006 Elsevier Ltd. All rights reserved.
CHIRAL LITHIUM AMIDE BASE DESYMMETRIZATION OF A RING FUSED IMIDE: FORMATION OF (3aS,7aS)-2-[2-(3,4-DIMETHOXYPHENYL)-ETHYL]-1,3-DIOXO-OCTAHYDRO-ISOINDOLE-3a-CARBOXYLIC ACID METHYL ESTER
作者:Rodeschini, Vincent、Simpkins, Nigel S.、Zhang, Fengzhi、Beenen, Melissa A.、Ellman, Jonathan A.
DOI:10.15227/orgsyn.084.0306
日期:——
Introduction of Multiple Elements of Chirality around an Aromatic Core and an Approach to Enantiomerically PureC3-Symmetric Ligands
作者:M. Paola Castaldi、Susan E. Gibson、Matthew Rudd、Andrew J. P. White
DOI:10.1002/anie.200500020
日期:2005.5.30
Enantioselective copper-catalyzed conjugate addition using chiral diaminocarbene ligands
作者:Frédéric Guillen、Caroline L. Winn、Alexandre Alexakis
DOI:10.1016/s0957-4166(01)00387-1
日期:2001.8
Chiral diaminocarbene ligands, generated by in-situ deprotonation of the corresponding chiral imidazolinium salts, are shown to be efficient ligands in the asymmetric copper-catalyzed 1,4-conjugate addition of diethylzinc to enones, allowing enantiomeric excesses of up to 51% to be achieved. (C) 2001 Elsevier Science Ltd. All rights reserved.
Diastereoselective synthesis of 1,2-diphenyl-1,2-diaminoethanes by Yb(OTf)3 accelerated reductive coupling of imines
New reaction protocols have been established to perform the reductive coupling of N-benzyl benzaldimines to 1,2-diphenyl-1,2-diaminoethanes in mild, stereoselective, and catalytic conditions by the use of SmI2 and Yb(OTf)(3). (C) 1998 Elsevier Science Ltd. All rights reserved.
Simple synthesis of a C2 symmetric vicinal diamine: Highly diastereoselective Grignard addition to a chiral bis-imine
作者:Kimberley Bambridge、Michael J. Begley、Nigel S. Simpkins
DOI:10.1016/s0040-4039(00)76916-4
日期:1994.5
The reaction of the enantiomerically pure bis-imine derived from glyoxal and (R)-alpha-methylbenzylamine with PhMgCl in diethylether is highly diastereoselective, resulting in the selective formation of the C-2 symmetric vicinal diamine 7.