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An in situ generated catalyst from readily available RuH(2)(PPh(3))(4), an N-heterocyclic carbene (NHC) precursor, NaH, and acetonitrile was developed. The catalyst showed high activity for the amide synthesis directly from either alcohols or aldehydes with amines. When a mixture of an alcohol and an aldehyde was reacted with an amine, both of the corresponding amides were obtained with good yields. Homogeneous Ru(0) complexes such as (eta(4)-1,5-cyclooctadiene)(eta(6)-1,3,5-cyclooctatriene)ruthenium [Ru(cod)(cot)] and Ru(3)(CO)(12) were also active in the amidation of an alcohol or an aldehyde with the help of an in situ generated NHC ligand.

Acceptorless dehydrogenative oxidation of primary amines into nitriles using an in situ complex derived from commercially available dichloro(1,5-cyclooctadiene) ruthenium(II) complex and simple hexamethylenetetramine has been demonstrated. The synthetic protocol is highly selective and yields the nitrile compounds in moderate to excellent yields and produces hydrogen as the sole byproduct. [ABSTRACT FROM AUTHOR]

An iridium(III)-catalyzed tandem synthesis of amides and amines from esters under solvent-free conditions is described. A commercially available iridium(III) complex, [Cp*IrCl2]2, with sodium acetate showed the best activity for the synthesis of amides and secondary amines. The amide was formed by ester-amide exchange which generates an alcohol in situ which is subsequently transformed to a secondary amine via hydrogen autotransfer. This synthetic protocol with high atom economy generates water as the sole by-product and can afford amides and amines from various esters in a one-pot reaction, expanding the synthetic versatility of ester transformations. [ABSTRACT FROM AUTHOR]

• Dehydrogenation of Animes and Alcohols using simple RuCl 3 ·nH 2 O. • Hydrogen is only by-product and no acceptor is used. • Nitriles, imines and ketones are produced in excellent yields. A highly efficient, economic and environmental friendly catalyst system has been developed for the dehydrogenation of alcohols and amines using simple RuCl 3 ·nH 2 O and N - benzylhexamethylenetetramine. The in situ catalyst system efficiently oxidized the primary and secondary amines and secondary alcohols into nitrile, imine and ketone products, respectively in moderate to excellent yields. The developed catalyst system was also found to be efficient for the dehydrogenation of N -heterocyles. A detailed mechanism study revealed the first example of N - benzylhexamethylenetetramine (HMTA-Bz) being simultaneously acting as base, reducing agent and hydride source to generate the [Ru(II)(H) 2 species as the active catalyst. The mechanism studies also revealed both the alcohol and amine oxidation involves dehydrogenative pathway with the evolution of hydrogen as the only by-product. The developed catalyst system also provides possible platform for the release of hydrogen from liquid organic hydrogen carriers (LOHCs). [ABSTRACT FROM AUTHOR]

[Display omitted] A ruthenium hexamethylenetetramine complex [RuCl 2 (p -cym)HMTA] was prepared in quantitative yield at room temperature for 30 m. NMR and fluorescence spectroscopic studies revealed that the complex is unstable in solution resulting in the decomposition of HMTA unit with the elimination of p -cymene moiety. The newly synthesized complex is very efficient for the conversion of amines and alcohols into imines and ketones, respectively, in the absence of any base/additive/acceptor. The synthetic viabilty of the catalyst was successfully tested for the gram scale synthesis of industrially important product bis(4-chlorophenyl)methanone. The spectroscopic and experimental studies showed that ruthenium-hydride species was formed as active catalyst during the catalytic reactions and oxidation of alcohols and amines follows a dehydrogenative oxidation mechanism. The amount of hydrogen gas evolved during the ruthenium complex catalysed oxidation of diphenylmethanol was estimated to be 92%, implies the potential usage of catalyst in the field of liquid organic hydrogen storage. [ABSTRACT FROM AUTHOR]