Cycloaddition reactions of allenes with N-phenylmaleimide. A two-step, diradical-intermediate process
作者:Daniel J. Pasto、Peter F. Heid、Steven E. Warren
DOI:10.1021/ja00377a022
日期:1982.6
e process. The stereochemical features controlling the formation of the stereoisomeric diradical intermediates and their ring closures are discussed. In addition to the cycloaddition processes, competitive ene reactions occur to produce intermediate dienes, which react further to produce 1:2 adducts or nonreactive alkyne-containing 1:1adducts. These ene reactions also appear to proceed via diradical
A synthesis of conjugated dienes from aromatic, five-membered heterocycles
作者:Ernest Wenkert、Michael H. Leftin、Enrique L. Michelotti
DOI:10.1039/c39840000617
日期:——
Reaction of furan, thiophene, selenophene, and tellurophene as well as 2-methyl and 2,5-dimethyl derivatives of the first two heterocycles with phenyl-, methyl-, and n-butyl-magnesium bromides in the presence of ligated nickel dichloride are shown to yield buta-1,3-dienes mostly with retention of configuration.