An Efficient Synthesis of Arylcyclobutenes via Cross-Coupling of Aryl Halides with 1-(Tri- n -butylstannyl)cyclobutene
作者:Jing Feng、Günter Szeimies
DOI:10.1016/s0040-4020(00)00350-1
日期:2000.6
1-Tri-n-butylstannylcyclobutene, obtained from 1-bromocyclobutene by lithium/bromine exchange and transmetalation with chloro-tri-n-butylstannane, could be effectively converted with aryl halides into 1-arylcyclobutenes by the Stille cross-coupling procedure. Hetero-aryl halides like 2-bromopyridine and 2-iodothiophene were also successfully coupled, and in 1,3,5-tribromobenzene, 1,2,4,5-tetrabromobenzene and hexabromobenzene all bromine atoms could be exchanged. (C) 2000 Elsevier Science Ltd. All rights reserved.
High Regioselectivity in the Ring-Opening Cross-Metathesis of 1-Arylcyclobutene
Rh(II)-Catalyzed Ring Expansion of Cyclopropyl N-Tosylhydrazones to 1-Substituted Cyclobutenes
作者:Jingfeng Huo、Jianbo Wang、Wenbai Ouyang
DOI:10.1055/a-1995-5960
日期:——
useful synthetic intermediates as well as important motifs in functional molecules. Herein, we report a straightforward access toward monosubstituted cyclobutenes from cyclopropyl N-tosylhydrazone. 1,2-Aryl or -alkyl shift of the Rh(II) carbene intermediate plays the key role in this transformation.