Mechanistic and Synthetic Studies of Biaryl Birch Reductions

Abstract

AbstractThe Birch reduction of biaryls generally converts one of the two arenes into a cyclohexa-1,4-diene. Biaryls are more reactive than monocyclic arenes under the Birch conditions. Unlike the reduction of monocyclic arenes, biaryl reduction proceeds through two consecutive electron transfer steps before the protonation of the dianion intermediate. The biaryl reductions and subsequent alkylations in one pot rapidly increase the molecular complexity and thus have been used in the synthesis of natural products and drug-like molecules.1 Introduction2 The Physical Organic Chemistry of the Birch Reduction of Biaryls3 Biaryls as the Mediators of Electron Transfer4 Methods for the Dissolving-Metal Reduction of Biaryls5 Intercepting the Biaryl Reduction Intermediates with Electrophiles6 Synthetic Applications of the Dissolving-Metal-Mediated Reductions of Biaryls7 Outlook