Catalytic Generation of Benzyl Anions from Aryl Ketones Utilizing [1,2]-Phospha-Brook Rearrangement and Their Application to Synthesis of Tertiary Benzylic Alcohols

A synthetic method of tertiary alcohols was developed based on the formal umpolung addition of aryl ketones with electrophiles utilizing the [1,2]-phospha-Brook rearrangement under Br & oslash;nsted base catalysis. The addition reaction of alpha-hydroxyphosphonates, derived from alkyl aryl- and diaryl ketones, with electrophiles such as phenyl vinyl sulfone, afforded phosphates having a tertiary alkyl group, which were readily convertible to the corresponding tertiary benzylic alcohols. This operationally simple protocol provides efficient complementary access to tertiary alcohols that are difficult to synthesize by conventional methods. A method for the synthesis of tertiary alcohols was developed based on the formal umpolung addition of aryl ketones with electrophiles utilizing the [1,2]-phospha-Brook rearrangement under Br & oslash;nsted base catalysis. The addition reaction of alpha-hydroxyphosphonates, derived from aryl ketones, with electrophiles afforded phosphates having a tertiary alkyl group, which were readily convertible to the corresponding tertiary benzylic alcohols. image