1,4-Addition of tetraethyl fluoromethylenebisphosphonate to α,β-unsaturated compounds

Tetraethyl fluoromethylenebisphosphonate in the presence of cesium carbonate in DMF undergoes efficient 1,4-addition to Michael acceptors having terminal double bond such as α,β-unsaturated ketones, esters, sulfones, sulfoxides, and phosphonates to yield the corresponding adducts (α-alkyl-α-fluoromethylenebisphosphonates) in good to excellent yields.

Graphical abstractTetraethyl fluoromethylenebisphosphonate in the presence of cesium carbonate in DMF undergoes efficient 1,4-addition to Michael acceptors having terminal double bond such as α,β-unsaturated ketones, esters, sulfones, sulfoxides, and phosphonates to yield the corresponding adducts (α-alkyl-α-fluoromethylenebisphosphonates) in good to excellent yields.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► 1,4-Addition of tetraethyl fluoromethylenebisphosphonate to alfa,beta-unsaturated compounds. ► Michael acceptors having terminal double bond provide alfa-alkyl-alfa-fluoromethylenebisphosphonates in good yields. ► Michael acceptor having terminal triple bond give a mixture of E and Z adduct in moderate yield. ► Beta-substituted Michael acceptors are unreactive.