A synthesis of substituted oxaphospholes from in situe generated isatin from phthalaldehyde

The reaction of activated acetylenic compounds with triphenylphosphine (Ph3P) in the presence of in situe generated of N-alkyl isatin from the reaction of phthalaldehye, ammonium acetate and alkyl halide led to oxaphosphole derivatives in good yields. The reaction of dialkyl acetylenedicarboxylates with Ph3P in the presence of N-alkylisatins led to other derivatives of oxaphosphole in good to excellent yields.