Simple preparation of (2, 2′-Biphenylylene)phenylphosphine oxide and role of triphenylphosphine oxide as a mediator for formation of biaryl derivatives

Abstract

(2, 2′-Biphenylylene)phenylphosphine oxide (3) was prepared simply by the reaction of triphenylphosphine oxide (1) with phenyllithium and subsequently with aqueous hydrogen peroxide in acetic acid. The oxide 3 reacted with lithium diisopropylamide (LDA) and then with several electro-philes to afford regiospecifically ortho-substituted compounds in moderate yields, which were converted to unsymmetrical 2-and 2, 3′-substituted 1,1′-biaryls and triphenylphosphine oxide (1).