Catalytic aminohalogenation methods enable the regio- and stereoselective vicinal difunctionalization of alkynes, allenes and alkenes with amine and halogen moieties. A range of protocols and reaction mechanisms including organometallic, Lewis base, Lewis acid and Brønsted acid catalysis have been disclosed, enabling the regio- and stereoselective synthesis of halogen-functionalized acyclic amines and nitrogen heterocycles. Recent advances including aminofluorination and catalytic enantioselective aminohalogenation reactions are summarized in this review.

Structures of zeolite-anchored organorhodium complexes undergoing conversions with gas-phase reactants were characterized by infrared spectra bolstered by calculations with density functional theory and analysis of the gas-phase products. Structurally well-defined zeolite-supported rhodium diethylene complexes were synthesized by chemisorption of Rh(C(2)H(4))(2)(acac) (acac = CH(3)COCHCOCH(3)) on dealuminated Y zeolite, being anchored by two Rh-O bonds, as shown by extended X-ray absorption fine structure (EXAFS) spectroscopy. In contrast to the nonuniformity of metal complexes anchored to metal oxides, the near uniformity of the zeolite-supported species allowed precise determination of their chemistry, including the role of the support as a ligand. The anchored rhodium diethylene complex underwent facile, reversible ligand exchange with deuterated ethylene at 298 K, and ethylene ligands were hydrogenated by reverse spillover of hydrogen from support hydroxyl groups. The supported complexes reacted with CO to form rhodium gem-dicarbonyls, which, in the presence of ethylene, gave rhodium monocarbonyls. The facile removal of ethylene ligands from the complex in H(2)-N(2) mixtures created coordinatively unsaturated rhodium complexes; the coordinative unsaturation was stabilized by the site isolation of the complexes, allowing reaction with N(2) to form rhodium complexes with one and with two N(2) ligands. The results also provide evidence of a new rhodium monohydride species incorporating a C(2)H(4) ligand.

Transition metal carbides often display electronic and catalytic properties that are similar to Pt-group metals. In this tutorial review, we describe the feasibility of replacing the Pt-group metal component in bimetallic systems with metal carbides. By supporting a metal monolayer on a carbide substrate, these bimetallic surfaces exhibit similar catalytic and electrocatalytic activity to the corresponding Pt-based bimetallic systems while demonstrating the advantages of lower cost and higher thermal stability. Another promising aspect is that the carbide substrates often promote the formation of small, flat metal particles with novel catalytic properties. We review the synthesis, characterization, and utilization of carbide-supported metal surfaces in heterogeneous catalysis and electrocatalysis. An overview is given for both theoretical and experimental investigations, and trends are drawn from the literature. We also discuss opportunities for future research on carbide-supported metal surfaces.