Ynones and ynoates react with pinacolborane in a divergent manner in the presence of nucleophilic phosphine catalysts. Ynones are transformed to the corresponding propargyl alcohols in good yields with high regio- and chemoselectivity. Ynoates undergo highly regio- and stereoselective trans-hydroboration to produce E-vinylboronates. Impressive divergence in reactivity of ynones and ynoates can be traced back to the mechanistic aspects of 1,2-reduction and trans-hydroboration. A comparative analysis of the two pathways paints a complex picture in which different reaction rates control selectivity in these seemingly unrelated processes and explains how sufficiently acidic protons in the reaction mixtures can be used to steer the selectivity in different directions.

Oxidative DNA damage is recognized by 8-oxoguanine (8-oxoG) DNA glycosylase 1 (OGG1), which excises 8-oxoG, leaving a substrate for apurinic endonuclease 1 (APE1) and initiating repair. Here, we describe a small molecule (TH10785) that interacts with the phenylalanine-319 and glycine-42 amino acids of OGG1, increases the enzyme activity 10-fold, and generates a previously undescribed β,δ-lyase enzymatic function. TH10785 controls the catalytic activity mediated by a nitrogen base within its molecular structure. In cells, TH10785 increases OGG1 recruitment to and repair of oxidative DNA damage. This alters the repair process, which no longer requires APE1 but instead is dependent on polynucleotide kinase phosphatase (PNKP1) activity. The increased repair of oxidative DNA lesions with a small molecule may have therapeutic applications in various diseases and aging.

Ynones are efficiently reduced with a mild hydride donor in the presence of a catalytic amount of nucleophilic phosphines. The reactions are selective 1,2-reductions that give propargyl alcohols in yields of up to 96%. It is proposed that success in these reactions depends on the activation of ynones by a Lewis base catalyst. A protic additive plays a key role in suppressing the undesired reaction pathways and accelerating the 1,2-reductions.

Benzothiazoles undergo regioselective C2−H functionalization with triphenylphosphine to form thiazol-2-yltriphenylphosphonium salts, and these phosphonium salts react with a wide range of O-and N-centered nucleophiles to give the corresponding ethers, amines, and C−N biaryls. The reactions proceed under mild conditions and allow for the recovery of triphenylphosphine at the end of the sequence. In the presence of hydroxide, phosphonium salts undergo disproportionation, resulting in the reduction of the benzothiazole, which is useful for specific C2 deuteration of benzothiazoles.

Medicinally relevant substituted benzothiazoles and thiazoles are prepared under mild conditions by a regioselective C2–H chalcogenation via preparation of the phosphonium salt and the subsequent reaction with S- and Se-centered nucleophiles.