An asymmetric linear alkyl alkyne addition to aromatic aldehydes catalyzed by the Ti-(R)-BINOL system is reported with high enantioselectivity and yield. Our study expands upon the synthetic scope of propargylic alcohols, which could serve as potentially useful intermediates for the synthesis of various natural products. (C) 2011 Elsevier Ltd. All rights reserved.
Amino thiols versus amino alcohols in the asymmetric alkynylzinc addition to aldehydes
作者:Sílvia Subirats、Ciril Jimeno、Miquel A. Pericàs
DOI:10.1016/j.tetasy.2009.05.029
日期:2009.7
A series of modular amino thiol and amino alcohol ligands have been synthesized in enantiopure form from common enantiopure precursors. Their structures have been optimized for performance in the asymmetric alkynylzinc addition to aldehydes, and a direct comparison of the effect of the S and 0 coordinating atoms on the catalytic outcome of these ligands has been performed. Amino thiols have shown to be superior as ligands for this type of chemistry. (C) 2009 Elsevier Ltd. All rights reserved.
Efficient ligands, chiral 2-[2,2-dimethyl-1-(2-pyridyl)propoxy]-1,1-diarylethanols for highly enantioselective addition of alkynylzinc reagents to various aldehydes
作者:Miyuki Ishizaki、Osamu Hoshino
DOI:10.1016/s0957-4166(00)86262-x
日期:1994.10
Formation of optically active secondary alkynyl alcohols (3) (up to 95% e.e.) by the catalysed asymmetric addition of alkynylzinc reagents to aromatic and aliphatic aldehydes in the presence of the tridentate title ligands (1a-c) is described. Interestingly, enantioselectivity in the reaction was proved to be remarkably dependent on the structures of alkynylzinc reagents.