Catalytic Generation and Intermolecular Addition of Diarylmethyl Anions Utilizing [1,2]‐Phospha‐Brook Rearrangement Under Brønsted Base Catalysis

An intermolecular addition reaction involving an unconventional combination of a diarylmethyl anion and an electrophile, which is mediated by the [1,2]‐phospha‐Brook rearrangement under Brønsted base catalysis, was developed. Diarylmethyl anions having a benzofuran moiety were generated through the rearrangement with the aid of a catalytic amount of phosphazene base P2‐ t Bu. The resulting carbanion intermediates were trapped by various electrophiles, such as α,β‐unsaturated ketones, aryl aldehydes, α‐ketoesters, and N ‐Boc imines, providing the corresponding diarylalkane derivatives in good yields.