Chalcogen electrophile induced rearrangement of 1-alkynyltrialkyl borates: controlled syntheses of trisubstituted olefins from 1-alkynes
作者:Julien Gerard、László Hevesi
DOI:10.1016/s0040-4020(01)00904-8
日期:2001.10
The reaction of 1-alkynyltrialkyl borates with sulfenyl, selenenyl and tellurenyl halides produces β-chalcogeno alkenylboranes in good yields, with a cis relationship between the boron and the chalcogen moities. Protodeborylation of these compounds by acetic acid, or by a transmetalation–protonolysis sequence, leads to vinyl chalcogenides, which can be converted to alkenes by means of a nickel catalyzed
Alkynyl sulfides and selenides from alkynyl bromides and diorganoyl chalcogenides promoted by copper(I) iodide
作者:Antonio L. Braga、Aurélia Reckziegel、Paulo H. Menezes、Hélio A. Stefani
DOI:10.1016/0040-4039(93)85084-a
日期:1993.1
Alkynyl sulfides and selenides were obtained in good yields by reacting alkynyl bromides with diorganoyl disulfides and diselenides in hexamethylphosphoric triamide (HMPA) in the presence of copper (I) iodide.
Addition of hydrogen halides to acetylenic selenides. Synthesis of 1-halo-1-selenoalkenes
作者:João V. Comasseto、Paulo H. Menezes、Helio A. Stefani、Gilson Zeni、Antônio L. Braga
DOI:10.1016/0040-4020(96)00505-4
日期:1996.7
Acetylenic selenides react with HX (X=Cl, Br, I) at room temperature to give 1-halo-1-selenoalkenes in good yields. The 1-iodo-1-selenoalkenes were transformed into the corresponding vinylic organometallics (M=Zn, Cu, Cr).
作者:Antonio L. Braga、Miriam I. Marchi、Leandro H. de Andrade、Claudio C. Silveira
DOI:10.1080/00397910008087336
日期:2000.2
beta-Bromovinyl chalcogenides were conveniently prepared in good yields by reacting alkynyl chalcogenides with bromine or by addition of organochalcogenyl bromide to bromoacetylenes in the presence of zinc bromide.