An Effective Borate-Mediated Approach to 1-Trifluoromethyl-1-hydroxy-3-ketophosphonates, Phosphinates, and Phosphine Oxides

Ethyl 1-trifluoromethyl-1-hydroxy-3-oxo-phosphonates, the related (methyl)phosphinates and (phenyl) phosphinates, and phosphine oxides were obtained in good yield via direct phosphonylation of acyltrifluoroacetones with diethyl phosphite, ethyl (methyl) phosphonite, ethyl (phenyl) phosphonite, and diphenylphosphine oxide in the presence of triethyl borate. The subsequent dehydration of the selected phosphonates and phosphinates proceeds smoothly affording previously unknown diethyl 1,2-unsaturated 1-trifluoromethyl-3-oxophosphonates, ethyl 1-trifluoromethyl-3-oxo(methyl)-, and ethyl 1-trifluoromethyl-3-oxo(phenyl) phosphinates in good yields.