A new palladium‐catalyzed intramolecular oxidativecycloisomerization of readily available starting materials, 2‐cinnamyl‐1,3‐dicarbonyls, has been demonstrated for the creation of structurally diverse 2‐benzyl furans. The cycloisomerization occurs by a regioselective 5‐exo‐trig pathway. The reaction shows a broad substrate scope with good to excellent yields. Furthermore, a one‐pot procedure has been
Efficient Metal-Catalyzed Direct Benzylation and Allylic Alkylation of 2,4-Pentanediones
作者:Magnus Rueping、Boris J. Nachtsheim、Alexander Kuenkel
DOI:10.1021/ol063048b
日期:2007.3.1
[reaction: see text] A highly effective metal-catalyzed benzylation and allylic alkylation of 2,4-pentanediones has been developed. This new bismuth-catalyzed direct carbon-carbon bond forming reaction provides the corresponding monoalkylated dicarbonyl compounds in high yields after short reaction times using the lowest amounts of catalyst (1 mol %) and the free alcohol. In addition, a new route to
A dual platinum‐ and pyrrolidine‐catalyzed direct allylic alkylation of allylic alcohols with various activemethylenecompounds to produce products with high monoallylation selectivity was developed. The use of pyrrolidine and acetic acid was essential, not only for preventing undesirable side reactions, but also for obtaining high monoallylation selectivity.
Ionic liquid/water as a recyclable medium for Tsuji–Trost reaction assisted by microwave
作者:Meng-chun Liao、Xin-hua Duan、Yong-min Liang
DOI:10.1016/j.tetlet.2005.04.002
日期:2005.5
An efficient microwave protocol is described for allylic substitution with various carbon and heteronucleophiles catalyzed by Pd(OAC)(2)/TPPTS in an [EMIm]BF4/H2O medium. The ionic liquid/water containing catalyst system can be recycled eight times without loss of activity. (c) 2005 Elsevier Ltd. All rights reserved.