Practical Synthesis of Linear α-Iodo/Bromo-α,β-unsaturated Aldehydes/Ketones from Propargylic Alcohols via Au/Mo Bimetallic Catalysis
作者:Longwu Ye、Liming Zhang
DOI:10.1021/ol901346k
日期:2009.8.20
An efficient synthesis of α-iodo/bromo-α,β-unsaturated aldehydes/ketones directly frompropargylicalcohols is described. This reaction is catalyzed collaboratively by two metal complexes, Ph3PAuNTf2 and MoO2(acac)2, and Ph3PO as an additive helps suppress undesired enone/enal formation. Notable features of this method include low catalyst loadings, mild reaction conditions, and mostly good to excellent
A method for preparing an α-halo enal or enone from an unprotected propargyl alcohol and an electrophilic halogen source catalyzed by the combination of a gold catalyst complex and a metal co-catalyst complex is disclosed. The method can be further enhanced by addition of an additive that facilitates suppression of a des-halo derivative.
Preparation of Organoaluminum Reagents from Propargylic Bromides and Aluminum Activated by PbCl2 and Their Regio- and Diastereoselective Addition to Carbonyl Derivatives
作者:Li-Na Guo、Hongjun Gao、Peter Mayer、Paul Knochel
DOI:10.1002/chem.201000523
日期:2010.8.23
propargylic and allenic aluminum reagents have been easily prepared by a direct insertion of aluminum into propargylic bromides in the presence of PbCl2 (1 mol %). These organoaluminum reagents react with carbonyl compounds to afford the corresponding allenic alcohols or homopropargylic alcohols in good to excellent yields with high regio‐ and diastereoselectivity.