Unexpected iron(iii) chloride-catalysed dimerisation of 1,1,3-trisubstituted-prop-2-yn-1-ols as an expedient route to highly conjugated indenes
作者:Weidong Rao、Philip Wai Hong Chan
DOI:10.1039/c003522j
日期:——
A method to prepare highly conjugated indenes efficiently by iron(III) chloride-catalysed dimerisation of trisubstituted propargylic alcohols under very mild conditions at room temperature is described. The reactions are rapid and operationally straightforward, giving the indene products in good yields and regioselectivity.
The asymmetric addition of lithium acetylides to carbonylcompounds in the presence of a chiral lithium binaphtholate catalyst was developed. A procedure involving the slow addition of carbonylcompounds to lithium acetylides improved the enantioselectivity. This reaction afforded diverse chiral secondary and tertiary propargylic alcohols in high yields and with good to high enantioselectivities.
Chiral lithium 3,3'-diphenylbinaphtholate successfully catalyzed the alkynylation of ketone with trimethoxysilylalkyne, affording chiral tertiary propargylic alcohols in high chemical yields and high enantioselectivities. The present reaction could be extended to the alkynylation of acetylpyridine, which afforded a biologically active pyridyl propargylic alcohol in good enantioselectivity. (c) 2010 Elsevier Ltd. All rights reserved.