One‐Pot Reaction of (β‐Amino‐α,α‐difluoroethyl)phosphonates with Trifluoromethylated Ketones via Aza‐Wittig Reagents

Abstract We report a one‐pot reaction of (β‐amino‐α,α‐difluoroethyl)phosphonates involving aza‐Wittig reagents, in which, difluoromethylphosphonate‐containing diazo and trifluoromethylated ketones assemble to furnish azo‐containing α‐fluorovinylphosphonates. Mechanism studies disclose a pathway, which contains an aza‐Wittig reaction, water addition to hydrazone, and C−F bond cleavage with an aza‐Wittig reagent as a key intermediate. This reaction is conducted at 60 °C affording a series of α‐fluorovinylphosphonate compounds in 42–94% yields and Z ‐stereoselectivity. This work opens a vision for the difluoroalkyl‐substituted diazos, and provides a strategy for the synthesis of α‐fluorovinylphosphonate derivatives. magnified image