Direct Synthesis\nof Sulfinylated Phenanthrenes via\nBF<sub>3</sub>‑Promoted Annulation of 2‑Alkynyl Biaryls\nwith Arylsulfinic Acids

A novel approach to sulfinylated phenanthrenes has been\ndeveloped\nby BF<sub>3</sub>-promoted annulation of 2-alkynyl biaryls with arylsulfinic\nacids. This approach utilizes readily available arylsulfinic acids\nas a sulfinyl source and affords a variety of sulfinylated phenanthrenes\nin good to excellent yields under simple and mild reaction conditions.