Rh‐Catalyzed Hydration/C−F Bond Cleavage of Fluorinated Diazoalkanes Enabling Synthesis of α‐Fluoro‐β‐ketophosphonates

Abstract (β‐Diazo‐α,α‐difluoroethyl)phosphonates have been emerging as useful building blocks in organic synthetic chemistry in recent years, which can be used as diazo analog or masked carbene for the rapid assembly of difluoromethylene phosphonate‐containing compounds. Herein, we elaborate a method for the synthesis of α‐fluoro‐β‐ketophosphonates from hydration/C−F bond cleavage of in situ generated (β‐amino‐α,α‐difluoroethyl)phosphonates via a Rh‐carbene intermediate. Divers (β‐amino‐α,α‐difluoroethyl)phosphonates are tolerated in this reaction affording α‐fluoro‐β‐ketophosphonates in good yields. This reaction used the in situ generated water as the coupling partner, which represents a reaction of (β‐diazo‐α,α‐difluoroethyl)phosphonates and also a method for generating bioactive α‐fluoro‐β‐ketophosphonates.