Development of the Meyer-Schuster Rearrangement on Propargylic Alcohols with Fluorinated Chains

The Meyer-Schuster Rearrangement (MSR) is a challenging process for propargylic alcohols bearing fluorine atom(s) on their chains. Most classical reagents/catalysts failed to perform the MSR but, after extensive screening, we demonstrated that phosphomolybdic acid was the first efficient catalyst for the MSR with such derivatives. The scope and limitations have been studied, affording fluorine-containing enones as useful intermediates for the synthesis of targets with fluorine(s) on their side chains. It was exemplified by the preparation of a 2-piperidino-pyrimidine and a pyrazole. New enones with mono-, gem-difluoro- or trifluoro chains are easily obtained through the Meyer-Schuster Rearrangement (MSR), using phosphomolybdic acid as the catalyst selected after extensive screening.image