Brønsted Acid Promoted Sulfonylation of Propargylic Alcohols: Synthesis of Triaryl Allenyl Sulfones under Mild Conditions

Abstract An efficient and practical approach for the synthesis of triaryl allenyl sulfones from easily accessible propargylic alcohols was developed, by using sodium sulfinates as a sulfonyl source in the presence of Brønsted acid. The reaction proceeded via allenyl carbocation as the key intermediate and was followed by a nucleophilic attack of sodium sulfinates to produce allenyl sulfones in moderate to excellent yields.