Recent progress in dinitrogen functionalization: stoichiometric and catalytic reactions

An overview of dinitrogen activation and functionalization is presented with particular focus on bond formation between nitrogen and other elements, N–X (X = H, C, B). Progress in recent years is emphasized. This chapter is divided into four different sections. (a) N–H bond formation: of late, there have been a lot of developments employing Mo-pincer homogeneous catalysts in NH3 synthesis, including systems where H2O and ethylene glycol are used as proton sources. (b) Several new reactions in N–C bond formation have emerged mainly derived from dinitrogen activation involving bimetallic systems. This has provided accessibility to synthetic routes of value-added chemicals such as nitriles, aniline and pyrazole derivatives, where the nitrogen source is N2. (c) The fundamental understanding garnered from TM–N2 bonding has paved the way for frustrated Lewis pair type activation of small molecules by using a TM–N2 → LA motif along with 1,2- and 1,3-B–H bond activations. (d) Metal-free p-block-based borylene radicals have rivalled TM-based activation of N2, and this area has flourished in the past couple of years.