DFT and Experimental Studies on the PtX2/X–-Catalyzed Olefin Hydroamination: Effect of Halogen, Amine Basicity, and Olefin on Activity, Regioselectivity, and Catalyst Deactivation

Catalysis and regioselectivity in hydrofunctionalization reactions of unsaturated carbon bonds. Part II. Hydroamination

This review continues consideration of the regioselectivity problem in the catalyzed hydrofunctionalization of unsaturated organic compounds and addresses hydroamination of unsaturated hydrocarbons. Particular parts of the review deal with reactions of alkenes, alkynes, allenes and dienes. It is shown that the selectivity of hydroamination depends on the natures of the reactants and the catalyst. Conditions of the reactions are described; in some cases, reaction mechanisms are discussed. Reactions for which divergent regioselectivity is possible are noted.

The bibliography includes 249 references.

Dedicated to the memory of V.V.Markovnikov.

Deviation from the trans-Effect in Ligand-Exchange Reactions of Zeise's Ions PtCl3(C2H4)- with Heavier Halides (Br-, I-)

Four new Zeise's family ions with mixed-halide ligands, i.e., PtCl_nX_3-n(C₂H₄)^- (X = Br, I; n = 1, 2), were synthesized via ligand-exchange reactions of KX salts with KPtCl₃(C₂H₄) in aqueous solutions, and were detected in vacuum via electrospray ionization mass spectrometry. Their photoelectron spectra reveal a series of well-resolved spectral peaks with their electron binding energies (EBEs) decreasing with increasing halide size, with I having a much stronger effect than Br, i.e., 4.57 (-Cl₃) > 4.56 (-Cl₂Br) > 4.53 (-ClBr₂) > 4.34 (-Cl₂I) > 4.30 eV (-ClI₂). Ab initio electronic structure calculations including spin-orbit coupling (SOC) predict that the cis- and trans-isomers are nearly isoenergetic with the cis-isomer for -Cl₂X and the trans-isomer for -ClX₂ slightly favored, respectively. Excited-state spectra calculated with time-dependent density functional theory (TDDFT), and their comparison with the observed ones, suggest that for each species both the cis- and trans-configurations coexist in the experiments and contribute to the observed spectra, a fact that clearly deviates from the prediction of the widely accepted trans-effect, which suggests that only one isomer would have formed.

Recent advances in metal free- and late transition metal-catalysed hydroamination of unactivated alkenes

This Perspective article outlines some of the recent advancements in the development of (chiral) metal-free and late transition metal catalysts for hydroamination of unactivated alkenes.