A combination of a catalytic amount of a Niâphosphine complex and triethylaluminium or chlorodiethylaluminium is able to selectively cyclize a number of 1,7-heptadienes to methylidene(methyl)cyclopentanes and cyclopentenes even in cases where the dienes are prone to deallylation.
Palladium-Catalyzed Cyclizations of 1,6-Dienes in the Presence of Lewis Acids
作者:Chang Ho Oh、Jung Duk Kim、Je Wook Han
DOI:10.1246/cl.2001.1290
日期:2001.12
Palladium-catalyzed cyclizations of several 1,6-dienes were accomplished by utilizing a catalytic amount of additives. Use of Lewis acids gave the endocyclic compounds, while use of silver(I) salts gave the exocyclic compounds.
Phosphinite Ligand Effects in Palladium(II)-Catalysed Cycloisomerisation of 1,6-Dienes: Bicyclo[3.2.0]heptanyl Diphosphinite (B[3.2.0]DPO) Ligands Exhibit Flexible Bite Angles, an Effect Derived from Conformational Changes (exo- orendo-Envelope) in the Bicyclic Ligand Scaffold
作者:Ian J. S. Fairlamb、Stephanie Grant、Simona Tommasi、Jason M. Lynam、Marco Bandini、Hao Dong、Zhenyang Lin、Adrian C. Whitwood
DOI:10.1002/adsc.200600346
日期:2006.11
Changes in bidentate ligand structure significantly affect catalytic activity in mono-cationic Pd(II)-catalysed 1,6-diene cycloisomerisation processes to give cyclopentene products. A bicyclo[3.2.0]heptanyl diphosphiniteligand (B[3.2.0]DPO, 3) is the first phosphorus-based bidentate ligand capable of promoting regioselective 1,6-diene cycloisomerisation. Trace quantities of water are essential for
Catalytic cycloisomerisation of 1,6-dienes in ionic liquids
作者:Xiaowei Miao、Joanna Feder-Kubis、Cédric Fischmeister、Juliusz Pernak、Pierre H. Dixneuf
DOI:10.1016/j.tet.2008.02.016
日期:2008.4
The ruthenium and palladium catalysed cycloisomerisation of 1,6-dienes in [bdmim][PF6], a room temperature ionic liquid (RTIL), is presented. The catalytic system comprising of [RUCl2(COD)](n) in the presence of (PrOH)-Pr-i was found to be particularly efficient and selective for the cycloisomerisation of the N,N-diallyltosylamide. This system can be reused several times without loss of performances and displays catalytic activity after a long storage period in the 1L. (c) 2008 Elsevier Ltd. All rights reserved.
Cycloisomerisation of 1,6-Dienes in the Presence of Cationic Palladium Catalysts