Synthesis of Unsymmetrical ortho-Biphenols and ortho-Binaphthols via Silicon-Tethered Pd-Catalyzed C–H Arylation

摘要

A mild, practical, and efficient method for the synthesis of unsymmetrical ortho-biphenols (including ortho-phenol-naphthols and ortho-binaphthols) has been developed. Unsymmetrical bis-aryloxy silanes, which were readily prepared in a semi-one-pot fashion, underwent the Pd-catalyzed intramolecular arylation followed by a routine TBAF desilylation step to furnish valuable unsymmetrical biphenols without necessity of isolation of 7-membered intermediates. The excellent functional group tolerance allows for synthesis of a variety of functionalized ortho-biphenols and ortho-binaphthols from easily available staring materials.