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Deoxygenation of phosphine oxides is of great significance to synthesis of phosphorus ligands and relevant catalysts, as well as to the sustainability of phosphorus chemistry. However, the thermodynamic inertness of P═O bonds poses a severe challenge to their reduction. Previous approaches in this regard rely primarily on a type of P═O bond activation with either Lewis/Brønsted acids or stoichiometric halogenating reagents under harsh conditions. Here, we wish to report a novel catalytic strategy for facile and efficient deoxygenation of phosphine oxides via successive isodesmic reactions, whose thermodynamic driving force for breaking the strong P═O bond was compensated by a synchronous formation of another P═O bond. The reaction was enabled by PIII/P═O redox sequences with the cyclic organophosphorus catalyst and terminal reductant PhSiH3. This catalytic reaction avoids the use of the stoichiometric activator as in other cases and features a broad substrate scope, excellent reactivities, and mild reaction conditions. Preliminary thermodynamic and mechanistic investigations disclosed a dual synergistic role of the catalyst.

The metal-free catalytic C–F bond activation of polyfluoroarenes was achieved with diazaphospholene as the catalyst and phenylsilane as the terminal reductant. Density functional theory calculations suggested a concerted nucleophilic aromatic substitution mechanism.

The sources of asymmetric induction in the photoinduced phase-transfer-catalytic perfluoroalkylation of β-ketoesters were interpreted by density functional theory calculations. The calculations indicated that multiple hydrogen-bonding interactions mode rather than π–π stacking interactions model better described the transition structure of the reaction. The quantitative estimation of these noncovalent interactions within the key transition states identified that the O–H···O and specific C–H···O hydrogen bonds play key roles for the stereocontrol.

A series of novel N-tert-butyl sulfinyl squaramide receptors have been designed and synthesized. Their interactions with a range of inorganic anions were studied in solution by 1H NMR spectroscopy. This new type of squaramide displayed better anion-binding abilities over conventional diphenyl squaramides. The single crystal analysis and DFT calulations implied the role of the tert-butyl C–H protons in binding Cl–. The energies of C–H···Cl–interactions were estimated to be 1.4–1.6 kcal/mol in solution.

An acidity scale of triazolium-based N-heterocyclic carbene precursors was established by measuring 25 compounds’ (10a–15b) equilibrium acidities in dimethyl sulfoxide (DMSO) solution using overlapping indicator method. The pKavalues ranged from 12.08 to 15.5, responding not only to the N-aryl motif, but also to the core structure. Excellent correlation was observed between the pKavalues and the Hammett substituent constants (σp).

N-tert-Butyl sulfinyl squaramides were used for chiral discrimination of α-hydroxyphosphonates using 31P NMR. A free energy relationship study indicates that both steric and the electronic effects influence the chiral recognition of the donors.

Controlling product selectivity in successive reactions of the same type is challenging owing to the comparable thermodynamic and kinetic properties of the reactions involved. Here, the synergistic interaction of the two phosphoryl groups in bisphosphine dioxides (BPDOs) with a bromo-phosphonium cation was studied experimentally to provide a practical tool for substrate–catalyst recognition. As the eventual result, we have developed a phosphonium-catalyzed monoreduction of chiral BPDOs to access an array of synthetically useful bisphosphine monoxides (BPMOs) with axial, spiro, and planar chirality, which are otherwise challenging to synthesize before. The reaction features excellent selectivity and impressive reactivity. It proceeds under mild conditions, avoiding the use of superstoichiometric amounts of additives and metal catalysts to simplify the synthetic procedure. The accessibility and scalability of the reaction allowed for the rapid construction of a ligand library for optimization of asymmetric Heck-type cyclization, laying the foundation for a broad range of applications of chiral BPMOs in catalysis.

The recent recognition of the novel application of a few traditional electrophilic trifluoromethylthiolating reagents as SCF3radical sources offers a remarkable new opportunity for the development of radical trifluoromethylthiolation reactions. Herein, the first trifluoromethylthio radical donating ability (Tt•DA) scale of electrophilic SCF3-transfer reagents has been developed. This scale is based on Y-SCF3bond dissociation energies, which were obtained by density functional calculations (M06-2X). Single electron transfer is revealed to exhibit a substantial Y-SCF3bond-weakening effect, thus significantly facilitating the SCF3radical (•SCF3) release. The results may aid in future novel radical SCF3-transfer reagent design and new reaction development.