Triphenylphosphine Oxide-d15, is the labeled analogue of Triphenylphosphine Oxide (T808980), (Orlistat USP Related Compound C) and a catalyst in the conversion of aldehydes into 1,1-dichlorides. Triphenylphosphine Oxide is used as a catalyst for the synthesis of hightly functionalized α-CF3 γ-keto esters.