Dual Nature of (Phenylseleno)cobaloxime in the Reaction with 2-Propynyl Derivatives
作者:Masaru Tada、Ritsuko Nagasaka
DOI:10.1246/bcsj.68.3221
日期:1995.11
Photolysis or thermolysis of (phenylseleno)cobaloxime gives a pair of radicals: phenylseleno radical and cobaloxime radical, which are considered to be equilibrated with the ion pair by a single electron transfer. The radical addition on the acetylenic moiety takes place when the 2-propynyl derivatives have weak leaving groups (OH, OPh, OAc). On the other hand, the ionic substitution with phenylseleno
Vinylic chalcogenides were synthesized stereospecifically by hydrochalcogenation of propargylic amines or alcohols mediated by cerium(III) chloride. The products were obtained in good yields and with high regio- and stereoselectivities. cerium chloride - vinylic chalcogenides - hydrochalcogenation - selenium - tellurium