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。
A new palladium catalysed-anion capture process is proposed, Examples are provided involving cyclisation of o-(ω-acetylenic)-aryl iodides and 2-bromo-1,6-enynes to heterocyclic- and carbocyclic-vinylpalladium species followed by hydride ion capture.
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。
Palladium Catalysed Tandem Cyclisation–Anion Capture Processes. Part 4: Organotin(IV) Transfer Agents
作者:Paul Fretwell、Ronald Grigg、Jose M Sansano、Visuvanathar Sridharan、Sukanthini Sukirthalingam、David Wilson、James Redpath
DOI:10.1016/s0040-4020(00)00659-1
日期:2000.9
Palladium(0) catalysed cascade mono- and bis-cyclisation-anion capture involving a wide variety of starter species, terminating species and organotin(IV) anion capture reagents are reported leading to a range of bridged, fused and spirocyclic products. The diastereoselectivity of the bis-cyclisation processes is explained in terms of steric effects in the transition states. (C) 2000 Elsevier Science Ltd. All rights reserved.