A facile, highly stereo- and regioselective hydrometalation of alkynes generating alkenylmetal complex is disclosed for the first time from a reaction of alkyne, carboxylic acid, and a zerovalent group 10 transition metal complex M(PEt(3))(4) (M = Ni, Pd, Pt). A mechanistic study showed that the hydrometalation does not proceed via the reaction of alkyne with a hydridometal generated by the protonation of a carboxylic acid with Pt(PEt(3))(4), but proceeds via a reaction of an alkyne coordinate metal complex with the acid. This finding clarifies the long proposed reaction mechanism that operates via the generation of an alkenylpalladium intermediate and subsequent transformation of this complex in a variety of reactions catalyzed by a combination of Brϕnsted acid and Pd(0) complex. This finding also leads to the disclosure of an unprecedented reduction of alkynes with formic acid that can selectively produce cis-, trans-alkenes and alkanes by slightly tuning the conditions.

The first nickel-catalyzed phosphinylation of C-S bonds forming C-P bonds is developed. This transformation can proceed readily with the simple Ni(cod) at a loading down to 0.1 mol% at the 10 mmol scale. A variety of aryl sulfur compounds, i.e. sulfides, sulfoxides and sulfones all couple with P(O)-H compounds to produce the corresponding organophosphorus compounds in high yields, which provides an efficient new method for the construction of C-P bonds.

Thef irst copper-catalyzed aerobic oxidative C(aryl) À OH bondf unctionalization of catechols is reported.U nder air, at room temperature,i nt he presence of ac opper catalyst, catechols react with amines to produce the corresponding benzoxazoles in high yields.M echanistic studies suggest that the reactionp roceeds via an intriguing competitive oxidation and as ynergetic catalysis between catechol and amine.

Iron-catalyzed aerobic oxidative functionalization of sp3 C–H bonds using a biofriendly iron catalyst in combination with O2 or air as the sole oxidant has been developed for the construction of N-heterocycles from easily available carboxylic acid derivatives and o-substituted anilines.