Accessing N-heteroarylated indoles and benzimidazoles from 2-alkynyl cyclohexadienimines and cyclohexadienones through metal-catalyzed tandem reactions
regioselective C–P cross coupling reaction of p-quinol ethers with secondary phosphine oxides is reported. The reaction provides a facile alternative method for the synthesis of 2-phosphinylphenols in good to high yields. Mechanistically, zinc triflate may serve as an oxophilic σ-Lewis acid to activate the C–O bond in p-quinol ether first. Then the regioselective attack of the phosphorus nucleophile at the α-carbon