In this context, our research group 1, 2 and others 3 recently developed a versatile method for synthesizing benzhydryl triarylphosphonium salts (11) via a convenient one-pot, regioselective fourcomponent coupling reaction using readily available starting materials (Figure ). These benzhydryl phosphonium salt building blocks (11) demonstrated exceptional reactivity and utility as evidenced by their selective post-functionalization at the C(sp 3 )-+ PPh3 position. In terms of reactivity, they have been shown to undergo photo-and radical-mediated reactions and can also act as C-electrophilic reactive groups, 2 engaging in reactions via an SN1 mechanism. These approaches enabled a range of transformations, including aminations, 2 thiolations, 2 arylations, 2 alkenylation, and alkylation to produce structural motifs commonly found in pharmaceuticals and agrochemicals. We envision that the research on these triarylphosphonium salts (11) can be further extended to explore new areas of their reactivity and applications in synthesis. We realize that one way to achieving this is by applying them to reduction and oxidation reactions, which could lead to the synthesis of important unsymmetrical (deuterated) diarylmethanes and diarylketones. In fact, this approach can be considered as a programmable, sequential two-steps strategy to synthesize these diarylmethanes and diarylketones from simple starting materials such as aldehydes and arenes. Here, we present a general and operationally straightforward approach for preparing phosphonium salts 11 and their late-stage transformation into various (deuterated) diarylmethanes (12 and 13) and diarylketone (14) compounds. This is achieved through reduction and oxidation reactions of 11, respectively, using only water (H₂O/ or D2O) as a reductant and O₂ as an oxidant (Figure ). 1