Efficient and Regioselective Ruthenium-catalyzed Hydro-aminomethylation of Olefins

A biphosphine copolymer encapsulated single-site Rh catalyst for heterogeneous regioselective hydroaminomethylation of alkenes

A novel porous organic polymer catalyst with in situ encapsulated single-site Rh (Rh@CPOL-DPMphos&p-3vPPh₃) was developed and employed in heterogeneous hydroaminomethylation of alkenes, affording the corresponding amines in good to excellent regioselectivity and catalytic activity by a one-pot method. The combined actions of hierarchical pore confinement and the biphosphine ligand derived from the POP catalyst contributed to the improved regioselectivity.

A Selective and General Cobalt-Catalyzed Hydroaminomethylation of Olefins to Amines

A new cobalt catalyst is presented for the domino hydroformylation-reductive amination reaction of olefins. The optimal Co-tert-BuPy-Xantphos catalyst shows good to excellent linear-to-branched (n/iso) regioselectivity for the reactions of aliphatic alkenes with aromatic amines under mild conditions. This system is far more selective than traditional cobalt(I) catalysts and even better than most known rhodium catalysts.

Copper-catalyzed borylative aminomethylation of C-C double and triple bonds with N,O-acetal

A copper-catalyzed borylaminomethylation of multiple carbon-carbon bonds with N,O-acetal and bis(pinacolato)diboron has been disclosed that offers efficient and expedient access to γ-amino boronates. The products contain a valuable amine and boronate, which are amenable to further elaboration, and have versatile synthetic utilities.

Ruthenium-Catalyzed PIII-Directed Remote ε-C-H Alkylation of Phosphines

The ruthenium-catalyzed remote ε-C-H alkylation of phosphines with tertiary alkyl halides has been developed. This novel P^III-directed C-H activation strategy tolerated various functional groups and delivered a wide variety of modified phosphines with excellent meta-site selectivity. Preliminary mechanistic studies indicated that a P^III-assisted ortho-cyclometalation/remote σ-activation pathway might be involved in this methodology.

Ruthenium-catalysed hydroxycarbonylation of olefins

A ruthenium-catalysed hydroxycarbonylation of olefins. We report a ruthenium-catalysed hydroxycarbonylation of unfunctionalized olefins.

Merging alkenyl C–H activation with the ring-opening of 1,2-oxazetidines: ruthenium-catalyzed aminomethylation of enamides

1,2-Oxazetidines have been utilized as formaldimine precursors for the direct aminomethylation of enamides under a Ru(ii) species.

Second-coordination sphere effects on the reactivities of Hoveyda–Grubbs-type catalysts: a ligand exchange study using phenolic moiety-functionalized ligands

The reactivities of Hoveyda–Grubbs-type complexes are tunable through second-coordination sphere effects caused by a functional group in the ligand.

A Multicatalytic Approach to the Hydroaminomethylation of α-Olefins

We report an approach to conducting the hydroaminomethylation of diverse α-olefins with a wide range of alkyl, aryl, and heteroarylamines at relatively low temperatures (70-80 °C) and pressures (1.0-3.4 bar) of synthesis gas. This approach is based on simultaneously using two distinct catalysts that are mutually compatible. The hydroformylation step is catalyzed by a rhodium diphosphine complex, and the reductive amination step, which is conducted as a transfer hydrogenation with aqueous, buffered sodium formate as the reducing agent, is catalyzed by a cyclometallated iridium complex. By adjusting the ratio of CO to H₂ , we conducted the reaction at one atmosphere of gas with little change in yield. A diverse array of olefins and amines, including hetreroarylamines that do not react under more conventional conditions with a single catalyst, underwent hydroaminomethylation with this new system, and the pharmaceutical ibutilide was prepared in higher yield and under milder conditions than with a single catalyst.

Selective formation of formic acid from biomass-derived glycolaldehyde with supported ruthenium hydroxide catalysts

Ceria-supported ruthenium hydroxide catalysts, Ru(OH)_x/CeO₂, with micro- and nanoparticle supports were applied for selective aerobic oxidation of glycolaldehyde (GAD) to formic acid (FA) in water under mild and base-free conditions.

Unexpected formation and conversion: role of substituents of 1,3-ynones in the reactivity and product distribution during their reactions with Ru3(CO)12

Electronic and steric effects of the substituents in 1,3-ynones play key roles in the product distribution and molecular structures.

Activation reactions of 2-pyridyl and 2-pyrimidinyl alkynes with Ru3(CO)12

The strong coordination ability of nitrogen atoms of N-heterocyclic groups plays key roles in the product distribution and molecular structures.

An efficient and recyclable ionic diphosphine-based Ir-catalyst for hydroaminomethylation of olefins with H2O as the hydrogen source

One-pot tandem hydroaminomethylation with H₂O as the hydrogen source was accomplished over an ionic diphosphine-based Ir-catalyst with high efficiency and recyclability.

Electronic and steric effects of substituents in 1,3-diphenylprop-2-yn-1-one during its reaction with Ru3(CO)12

Electronic and steric effects of substituents of alkynyl ketones play important roles in regulating reaction pathways.

Carbon Dioxide Transformation in Imidazolium Salts: Hydroaminomethylation Catalyzed by Ru-Complexes

The catalytic species generated by dissolving Ru3 (CO)12 in the ionic liquids 1-n-butyl-3-methyl-imidazolium chloride or 1-n-butyl-2,3-dimethyl-imidazolium chloride are efficient multifunctional catalysts for: (a) reverse water-gas shift, (b) hydroformylation of alkenes, and (c) reductive amination of aldehydes. Thus the reaction of alkenes with primary or secondary amines (alkene/amine, 1:1) under CO2 /H2 (1:1) affords the hydroaminomethylations products in high alkene conversions (up to 99 %) and selectivities (up to 96 %). The reaction proceeds under relatively mild reaction conditions (120 °C, 60 bar=6 MPa) and affords selectively secondary and tertiary amines. The presence of amine strongly reduces the alkene hydrogenation competitive pathway usually observed in the hydroformylation of terminal alkenes by Ru complexes. The catalytic system is also highly active for the reductive amination of aldehydes and ketones yielding amines in high yields (>90 %).

Diene hydroaminomethylation via ruthenium-catalyzed C-C bond forming transfer hydrogenation: beyond carbonylation

Under the conditions of ruthenium catalyzed transfer hydrogenation using 2-propanol as terminal reductant, 1,3-dienes engage in reductive C-C coupling with formaldimines obtained in situ from 1,3,5-tris(aryl)-hexahydro-1,3,5-triazines to form homoallylic amines. Deuterium labelling studies corroborate a mechanism involving reversible diene hydroruthenation to form an allylruthenium complex that engages in turn-over limiting imine addition. Protonolysis of the resulting amidoruthenium species releases product and delivers a ruthenium alkoxide, which upon β-hydride elimination closes the catalytic cycle. These transformations, which include enantioselective variants, represent the first examples of diene hydroaminomethylation.

Efficient Domino Hydroformylation/Benzoin Condensation: Highly Selective Synthesis of α-Hydroxy Ketones

An improved domino hydroformylation/benzoin condensation to give α-hydroxy ketones has been developed. Easily available olefins are smoothly converted into the corresponding α-hydroxy ketones in high yields with excellent regioselectivities. Key to success is the use of a specific catalytic system consisting of a rhodium/phosphine complex and the CO2 adduct of an N-heterocyclic carbene.

Recent advances in catalytic C-N bond formation: a comparison of cascade hydroaminomethylation and reductive amination reactions with the corresponding hydroamidomethylation and reductive amidation reactions

The design and catalytic implementation of tandem reactions to selectively create nitrogen-containing products under mild conditions has encountered numerous challenges in synthetic chemistry. Several known classes of homogeneously catalyzed carbon-nitrogen bond formation including hydroamination, hydroamidation, hydroaminoalkylation, hydroaminomethylation and reductive amination were reported in the literature. More recently, a new class of C-N bond formation consisting of hydroamidomethylation and reductive amidation extended the applicability of these synthetic methodologies. The tandem reactions do considerably impact on the selectivity and efficiency of synthetic strategies. This review highlights and compares selected examples of the hydroaminomethylation, reductive amination, hydroamidomethylation and reductive amidation reactions, and thus consequently reveals their potential applications in synthetic chemistry as well as chemical industries.

Highly regioselective osmium-catalyzed hydroformylation

The first highly regioselective and general osmium-catalyzed hydroformylation of olefins to aldehydes is reported. The combination of Os3(CO)12 and imidazoyl-substituted phosphine ligands allows n-selective (up to 99%) hydroformylation of bulk aliphatic as well as functional alkenes in good yields (64-87%).