Transfer hydrogenation (TH) has historically been dominated by Meerwein–Ponndorf–Verley (MPV) reactions. However, with growing interest in amine–boranes, not least ammonia–borane (H₃N⋅BH₃), as potential hydrogen storage materials, these compounds have also started to emerge as an alternative reagent in TH reactions. In this Review we discuss TH chemistry using H₃N⋅BH₃ and their analogues (amine–boranes and metal amidoboranes) as sacrificial hydrogen donors. Three distinct pathways were considered: 1) classical TH, 2) nonclassical TH, and 3) hydrogenation. Simple experimental mechanistic probes can be employed to distinguish which pathway is operating and computational analysis can corroborate or discount mechanisms. We find that the pathway in operation can be perturbed by changing the temperature, solvent, amine–borane, or even the substrate used in the system, and subsequently assignment of the mechanism can become nontrivial.

Although β-diketiminate complexes have been widely explored in stoichiometric studies, their use as catalysts is largely underdeveloped. With growing interest in the catalytic activity of complexes of the first row transition metals, primarily due to the untapped potential of such metal centers, along with the growing global focus on sustainable chemistry with earth abundant metals, this Perspective focuses on the use of β-diketiminate complexes of the first row transition metals as catalysts for the synthesis of small organic molecules.

A highly active iron(iii) complex for room temperature hydrophosphination is reported. The products of the hydrophosphination reaction are also useful ligands for iron catalyzed Negishi cross-coupling.