One-pot synthesis of gem-difluorostyrenes from benzyl bromide via olefination of phosphonium ylide with difluorocarbene

• gem-Difluorostyrenes can be synthesized from benzyl bromide.
• A sequential of reactions can occur in one-pot.
• Decarboxylative synthesis of gem-difluorostyrenes proved to be successful.

A new approach for the synthesis of gem-difluorostyrenes from benzyl bromide is described. Quaternization of triphenylphosphine with benzyl bromide to give phosphonium salts, deprotonation of the corresponding phosphonium salts to produce phosphonium ylide, and the subsequent olefination of phosphonium ylide with difluorocarbene generated from difluoromethylene phosphobetaine (Ph3P+CF2CO2−) by decarboxylation can occur smoothly in one-pot, furnishing the final gem-difluorostyrenes in good yields.

A one-pot synthesis of gem-difluorostyrenes from benzyl bromide via sequential reactions is described. The sequential reactions, including quarternization of triphenylphosphine, deprotonation and the gem-difluoroolefination proceeded smoothly to afford the final products in good yields.Figure optionsDownload as PowerPoint slide