A new reaction of 1-(2,4,6-trialkylphenyl)phospholes with heteroaromatic character; aromatic electrophilic substitution under the conditions of Friedel–Crafts acylation
Two (trialkylphenyl)phospholes (1 and 4) with significant heteroaromatic character due to the flattened P-pyramid underwent Friedel–Craftsacylation with acyl halides to afford 2-acylphosphole derivatives (e.g. 2 and 6, respectively); the 2-acyl-5-arylphosphole by-product 7 may have been formed by sigmatropic rearrangement through 2H-phosphole 9 or dibromophosphorane 12.