Nitrosation of 2-aryl-1,1-dibromocyclopropanes: synthesis of 3-aryl-5-bromoisoxazoles
作者:Oksana B. Bondarenko、Aleksandr A. Vinogradov、Pavel A. Danilov、Svetlana N. Nikolaeva、Anna Yu. Gavrilova、Nikolai V. Zyk
DOI:10.1016/j.tetlet.2015.10.026
日期:2015.11
An efficient transformation of 2-aryl-1,1-dibromocyclopropanes under the action of sulfur trioxide activated nitrosylchloride has been developed, providing a series of arylated 5-bromoisoxazoles with good yields. It is noteworthy that under the reported conditions the nitrosation–heterocyclization reaction proceeded with high regioselectivity leading exclusively to 3-aryl-5-bromoisoxazoles.
Ionic liquids accelerating cycloaddition between 1-aryl-2-halocyclopropenes and furan
作者:May-Fan Ding、Shaw-Tao Lin、Woan-Ju Chang
DOI:10.3998/ark.5550190.0011.219
日期:——
with furan in a RTIL to give a fair good yield of the [4+2]-cycloadducts with more than 90% of the exo-isomer. The imidazolium type ionicliquids are able to accelerate this cycloaddition process with high steric selectivity. Neither pyrrole nor thiophene undergoes the cycloaddition with cyclopropene to form the [4+2]-cycloadduct. 1-Aryl-3,3-difluoro-2-halocyclopropenes are inert towards furan even
Transformations of gem-dibromoarylcyclopropanes under nitrosation conditions on treatment with NOCl·(SO3) n
作者:O. B. Bondarenko、A. Yu. Gavrilova、S. N. Nikolaeva、N. V. Zyk
DOI:10.1007/s11172-016-1439-3
日期:2016.5
The reaction of 2-aryl-1,1-dibromocyclopropanes with adduct NOCl·(SO3)n leading to 3-aryl-5-bromoisoxazoles as a result of nitrosation—heterocyclization of the cyclopropane ring was studied. The reaction is accompanied with electrophilic aromatic bromination. The mechanism of the transformation was discussed, the optimal reaction conditions to enhance the reaction selectivity were developed.