Asymmetric nitroaldol reaction catalyzed by copper–diamine complexes: selective construction of two contiguous stereogenic centers
摘要:
Chiral copper(II) complexes of secondary bisamines derived from 1,2-diaminocyclohexane were successfully used in the diastereoselective nitroaldol reaction. The reactions were carried out in the presence of 10 mol % of the Cu(II) complex and 7.7 mol % of i-Pr2NEt in 2-propanol at -30 degrees C. Good to excellent yields, enantioselectivities of up to 99%, and moderate to excellent diastereoselectivities were obtained for both aromatic or aliphatic aldehydes and various prochiral nitrocompounds forming the corresponding beta-nitroalcohols with two contiguous stereocenters. (C) 2009 Elsevier Ltd. All rights reserved.
Chiral hybrid silica: sol–gel heterogenisation of trans-(1R,2R)-diaminocyclohexane ligands for the rhodium catalysed enantioselective reduction of acetophenone
作者:Anne Brethon、Joël J.E Moreau、Michel Wong Chi Man
DOI:10.1016/j.tetasy.2003.11.005
日期:2004.2
The synthesis of derivatives of trans-(1R,2R)-diaminocyclohexane with different substituents on the nitrogen atoms has been achieved. Rhodium complexes of these chiral ligands were evaluated as homogeneous catalysts for the asymmetric hydride transfer reduction (HTR) of acetophenone leading to moderate selectivities (ee = 0-57%). The silylation of a bromo-aryl derivative was successfully performed by a Heck's coupling reaction with vinyltriethoxysilane in the presence of a palladium catalyst. The immobilisation of this catalyst was then achieved by the sol-gel hydrolysis condensation. The resulting hybrid catalytic materials showed moderate selectivity, although much higher than the related homogeneous catalytic species. (C) 2003 Elsevier Ltd. All rights reserved.
Asymmetric allylation reactions of aromatic aldehydes with allyltrichlorosilane catalyzed by chiral bisformamide-type organocatalysts
作者:Yuya Tanimura、Kaori Ishimaru
DOI:10.1016/j.tetasy.2012.02.015
日期:2012.3
Asymmetricallylation reactions of aromatic aldehydes with allyltrichlorosilane were catalyzed by C2-symmetrical chiral bisformamides in the presence of potassium carbonate and potassium phosphate, to afford the corresponding homoallylic alcohols in excellent yields with up to 83% ee.
trans-1,3-Bis(Anthracen-9-Ylmethyl)Octahydro-Benzimidazoles: Synthesis and Study of Spectral Properties
作者:I. E. Tolpygin、K. S. Tihomirova、O. S. Popova、O. G. Nikolaeva、Yu. V. Revinskii、A. D. Dubonosov、V. A. Bren
DOI:10.1007/s10593-014-1446-y
日期:2014.4
The reaction between (+/-)-trans-cyclohexane-1,2-diamine and anthracene-9-carbaldehyde with a subsequent reduction of the condensation product gave N,N'-bis(anthracen-9-ylmethyl)cyclohexane-1,2-diamine. The interaction of this diamine with aldehydes was shown to produce octahydrobenz-imidazoles. The chemosensor properties of the obtained compounds were investigated, and a high affinity to Zn2+ cations was identified.