Ruthenium catalyzed reductive coupling of paraformaldehyde to trifluoromethyl allenes: CF3-bearing all-carbon quaternary centers.

Trifluoromethyl substituted allenes engage in ruthenium catalyzed reductive couplings with paraformaldehyde to form products of hydrohydroxymethylation as single regioisomers. This method enables generation of CF3-bearing all-carbon quaternary stereocenters.