Post-Transition State Bifurcation Controls Torsional Selectivity in Radical Addition of Allenes.

Post-transition state bifurcation (PTSB) has received wide attention in the field of reaction mechanism research due to its role in producing nonstatistical reaction selectivity, which cannot be solely explained by transition state theory. Particularly, even subtle molecular motions such as bond torsion can precipitate PTSB, thereby significantly complicating the quantitative understanding of dynamic selectivity. In this work, we found that the radical addition of allenes is an elementary transformation that generally exhibits PTSB stereoselectivity, where a single radical addition transition state can lead to both Z- and E-allylic radicals via the post-transition state allylic single bond torsion.

Direct Incorporation of Dinitrogen into an Aliphatic C-H Bond.

The activation of dinitrogen (N) and direct incorporation of its N atom into C-H bonds to create aliphatic C-N compounds remains unresolved. Incompatible conditions between dinitrogen reduction and C-H functionalization make this process extremely challenging. Herein, we report the first example of dinitrogen insertion into an aliphatic C-H bond on the ligand scaffold of a 1,3-propane-bridged [NN]-type dititanium complex.

(-Bu)NBr-Promoted N Splitting to Molybdenum Nitride.

Splitting of N via six-electron reduction and further functionalization to value-added products is one of the most important and challenging chemical transformations in N fixation. However, most N splitting approaches rely on strong chemical or electrochemical reduction to generate highly reactive metal species to bind and activate N, which is often incompatible with functionalizing agents. Catalytic and sustainable N splitting to produce metal nitrides under mild conditions may create efficient and straightforward methods for N-containing organic compounds.