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.
Stereoselective Synthesis of Chiral 3-Aryl-1-alkynes from Bromoallenes and Heterocuprates
作者:Anna Maria Caporusso、Alessia Zampieri、Laura Antonella Aronica、Donatella Banti
DOI:10.1021/jo0522456
日期:2006.3.1
The synthesis of chiral 3-aryl-1-alkynes 3 via cross-coupling of 3-alkyl- and 3,3-dialkyl-1-bromo-1,2-dienes 1 and arylbromocuprates (RCuBr)MgBr·LiBr 2 was examined. With phenylcopper reagents and its para-substituted derivatives, as well as with 2-naphthyl cuprates, the reaction gave compounds 3 with high regioselectivity and good yields on the chemically pure product. On the contrary, when ortho-substituted
Diastereoselectivity in the synthesis of bicyclic titanacyclopentenes from chiral 6-hepten-1-ynes
作者:Donatella Banti、Francesca Cicogna、Lorenzo Di Bari、Anna Maria Caporusso
DOI:10.1016/s0040-4039(00)01331-9
日期:2000.9
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.