Diastereoselectivity in the synthesis of bicyclic titanacyclopentenes from chiral 6-hepten-1-ynes
摘要:
A variety of chiral 6-hepten-1-ynes have been found to undergo cyclization to titanabicyclopentenes by (eta(2)-propene)Ti(Oi-Pr)(2) with excellent yields and degrees of exo-stereoselectivity depending on the substrate steric requirements. In the framework of a plausible cyclization mechanism several conformational features which can regulate the stereoinduction have been suggested. (C) 2000 Published by Elsevier Science Ltd.
Coupling of chiral 1-bromo-1,2-dienes with zinc-based cuprates: a new procedure for the regio and stereoselective synthesis of functionalized acetylenic compounds
作者:Anna Maria Caporusso、Sara Filippi、Federica Barontini、Piero Salvadori
DOI:10.1016/s0040-4039(99)02249-2
日期:2000.2
are found to be active in the cross-coupling reaction with allenic bromides affording acetylenic products with a high regio and stereoselective 1,3-anti substitution. The coupling process, which has been successfully extended to functionalized cuprates, can also be performed with alkylzinc chlorides in the presence of catalytic amounts of cuproussalts.
Construction of 1,5-Enynes by Stereospecific Pd-Catalyzed Allyl–Propargyl Cross-Couplings
作者:Michael J. Ardolino、James P. Morken
DOI:10.1021/ja302329f
日期:2012.5.30
The palladium-catalyzed cross-coupling of chiral propargyl acetates and allyl boronates delivers chiral 1,5-enynes with excellent levels of chirality transfer and can be applied across a broad range of substrates.