<i>t</i>BuLi-Mediated One-Pot Direct Highly Selective Cross-Coupling of Two Distinct Aryl Bromides
作者:Carlos Vila、Sara Cembellín、Valentín Hornillos、Massimo Giannerini、Martín Fañanás-Mastral、Ben L. Feringa
DOI:10.1002/chem.201502709
日期:2015.10.26
A Pd‐catalyzed direct cross‐coupling of twodistinctarylbromides mediated by tBuLi is described. The use of [Pd‐PEPPSI‐IPr] or [Pd‐PEPPSI‐IPent] as catalyst allows for the efficient one‐pot synthesis of unsymmetrical biaryls at room temperature. The key for this selective cross‐coupling is the use of an ortho‐substituted bromide that undergoes lithium–halogen exchange preferentially.
Various substituted 1,2-dihydrophthalic acids were synthesized by electroreduction of phthalic acids in excellent yields. The electrocyclic reaction of 1,2- dihydrophthalic acids or the methyl ester with alkynes gave 1,2-disubstituted benzenes and biphenyls in good yields together with fumaric acid or methyl fumarate.