A wide range of palladiumcatalysed regio- and stereo-specific 5-, 6- and 7-exo-dig mono-, bis- and tris-cyclisation processes of aryl and vinyl halides and allylic acetates are described. The mono- and bis-cyclisation processes terminate in hydride capture from piperidineformic acid or sodium formate. Addition of Tl2CO3 results in alkyne-allene isomerisation and leads, after cyclisation, to 1,3-dienes
描述了广泛的钯催化的芳基和乙烯基卤化物和烯丙基乙酸酯的区域特异性和立体特异性的5-,6-和7-exo-dig单,双和三环化方法。单环和双环化过程终止于从哌啶甲酸或甲酸钠中捕获氢化物。Tl 2 CO 3的添加导致炔-丙二烯异构化,并且在环化之后导致1,3-二烯,这使Diels-Alder加合物具有良好的收率。
Synthesis of Cyclopropanes by Intramolecular Attack ofN-Nucleophiles on the Central Carbon of (π-Allyl)palladium Complexes
amounts of palladium(0) complexes to form cyclopropanes such as 3a. This reaction is believed to proceed via an intermediate palladacyclobutane and is the first example of a noncarbon nucleophile attack on the centre carbon of an (η3-allyl)palladium complex leading, by reductive elimination, to cyclopropanes. The regiochemistry of the nucleophilicattack (central versus terminal carbon) depends on the nature
Palladium-catalyzed cycloreductions of haloene-ynes in the presence of triethylsilane
作者:Chang Ho Oh、Su Jin Park
DOI:10.1016/s0040-4039(03)00713-5
日期:2003.5
Haloene-ynes 1 with a palladium catalyst would form the alkenylpalladium intermediates via intramolecular Heck reactions, which were reductively cleaved with triethylsilane or formate ligand to give the cycloreduction products 3 in good to excellent yields. (C) 2003 Elsevier Science Ltd. All rights reserved.