Highly Enantioselective Catalytic Alkynylation of Ketones – A Convenient Approach to Optically Active Propargylic Alcohols
作者:Gui Lu、Xingshu Li、Yue-Ming Li、Fuk Yee Kwong、Albert S. C. Chan
DOI:10.1002/adsc.200606078
日期:2006.9
The development of highly enantioselective catalysts involving Cu(OTf)2 and chiral camphorsulfonamides for the alkynylation of ketone is described. The influences of Lewis acids, reaction conditions and chiral ligands on the outcome of the reaction are discussed. The best enantioselectivity (up to 97 % ee) was obtained in the alkynylation of 2′-chloroacetophenone. The scope of the reaction is also
Efficient catalytic transition-metal-free conditions for nucleophilic addition of arylacetylenes to aromatic ketones
作者:Junfeng Liu、Jin Lin、Ling Song
DOI:10.1016/j.tetlet.2012.02.058
日期:2012.4
A mild, efficient, and transition-metal-free method for nucleophilic addition of arylacetylenes to diverse aromatic ketones, using catalytic amount of tetrabutylammonium chloride as a promoter and solid KOH as a base in THF, was developed to afford aromatic tertiary propargylic alcohols with high and excellent yields. Aliphatic ketones also gave satisfactory results. (c) 2012 Elsevier Ltd. All rights reserved.
Direct Substitution of Secondary and Tertiary Alcohols To Generate Sulfones under Catalyst- and Additive-Free Conditions
An environmentally benign protocol that affords propargylic sulfones containing highly congested carbon centers from easily accessible alcohols and sulfinic acids with water as the only byproduct is reported. The reaction proceeded via an in situ dehydrative cross-coupling process by taking advantage of the synergetic actions of multiple hydrogen bonds rather than relying on an external catalyst and/or