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A new photocatalyzed route to amides from alcohols and amines mediated by visible light is presented. The reaction is carried out in ethyl acetate as a solvent. Ethyl acetate can be defined a green and bio-based solvent. The starting materials such as the energy source are easily available, stable, and inexpensive. The reaction has shown to be general and high yielding.

The present work describes a highly efficient synthetic strategy for amides via oxidative coupling of benzaldehydes or benzylamines with N-substituted formamides using a heterogeneous Co/Al hydrotalcite-derived catalyst in the presence of TBHP. A series of Co/Al hydrotalcite-derived catalysts (Cat-2, Cat-3, and Cat-4 with the Co2+/Al3+ molar ratio in the synthesis mixture as 1/1, 2/1 and 3/1) have been prepared by a simple co-precipitation method and characterized using powder XRD, XPS, FEG-SEM, EDS, FT-IR, DTG-TGA and N2 physical adsorption techniques. Among the as-prepared catalysts, Cat-3 exhibited excellent catalytic activity towards the direct amidation of benzaldehydes as well as benzylamines bearing various substituents into the corresponding amides at 100 °C using TBHP as an oxidant. The mechanistic investigation of the amidation reaction revealed that the reaction follows a radical pathway. Furthermore, the catalyst is easily separable and recyclable without considerable loss in catalytic activity.

Oxidative amidation is a valuable process for the transformation of oxygenated organic compounds to valuable amides. However, the reaction is severely limited by the use of an expensive catalyst and limited substrate scope. To circumvent these limitations, designing a transition-metal-based nanocatalyst via more straightforward and economical methodology with superior catalytic performances with broad substrate scope is desirable. To resolve the aforementioned issues, we report a facile method for the synthesis of nanocatalysts NiO and CuO by the sol-gel-assisted thermal decomposition of complexes [Ni(hep-H)(H2O)4]SO4 (SSMP-1) and [Cu(μ-hep)(BA)]2 (SSMP-2) [hep-H = 2-(2-hydroxylethyl)pyridine; BA = benzoic acid] as single-source molecular precursors (SSMPs) for the oxidative amidation of benzyl alcohol, benzaldehyde, and BA by using N,N-dimethylformamide (DMF) as the solvent and as an amine source, in the presence of tert-butylhydroperoxide (TBHP) as the oxidant, at T = 80 °C. In addition to nanocatalysts NiO and CuO, our previously reported Co/CoO nanocatalyst (CoNC), derived from the complex [CoII(hep-H)(H2O)4]SO4 (A) as an SSMP, was also explored for the aforementioned reaction. Also, we have carefully investigated the difference in the catalytic performance of Co-, Ni-, and Cu-based nanoparticles synthesized from the SSMP for the conversion of various oxygenated and unsaturated organic compounds to their respective amides. Among all, CuO showed an optimum catalytic performance for the oxidative amidation of various oxygenated and unsaturated organic compounds with a broad reaction scope. Finally, CuO can be recovered unaltered and reused for several (six times) recycles without any loss in catalytic activity.

A highly efficient copper-catalyzed approach to form amide bonds from formamides and carboxylic acids was developed. This protocol shows broad substrate scopes and high yields in the presence of 1 mol% catalyst and 4.0 equiv. formamides.

Oxidative coupling of methylamines with an aminyl radical to construct amides was developed in the presence of an I2/TBHP catalyst under acidic conditions via the two cleavages of the sp3 C-N bond of aryl-methylamines and the sp2 C-N bond of N-substituted formamides respectively. This transition-metal-free protocol provides a novel synthetic tool for the construction of N-substituted amides and a series of arylamides can be easily obtained with good yields. This journal is the Partner Organisations 2014.

A new, highly efficient in situ protocol (Cp2ZrCl2/LiAlH(OBu-t)3) is described for the generation of the Schwartz reagent which provides a convenient method for the amide to aldehyde reduction and the regioselective hydrozirconation-iodination of alkynes and alkenes. Highlighted are chemoselective reductions of benzamides derived by directed ortho metalation (DoM) chemistry, allowing the synthesis of valuable 1,2,3-substituted benzaldehydes. The single-step, three-component process proceeds in a very short reaction time, shows excellent functional group compatibility, and uses inexpensive and long-storage stable reducing reagents.

Disclosed is a new, catalytic, and general methodology for the chemical synthesis of biaryl, heterobiaryl, and polyaryl molecules by the cross-coupling of o-methoxybenzamides with aryl boroneopentylates. The reaction is based on the activation of the unreactive C-OMe bond by the proximate amide directing group using catalytic RuH2(CO)(PPh3)3 conditions. A one-step, base-free coupling process is thereby established that has the potential to supersede the useful two-step directed ortho metalation/cross- coupling reaction involving cryogenic temperature and strong base conditions. High regioselectivity, orthogonality with the Suzuki-Miyaura reaction, operational simplicity, minimum waste, and convenient scale-up make these reactions suitable for industrial applications.

A simple, cost effective and environmentally benign method is reported for the preparation of N,N-dimethylamides from carboxylic acids. The versatility of the method is determined by synthesising a large number of N,N-dimethylamide derivatives. Carboxylic acids are heated at 160-165°C in N,N-dimethylacetamide solvent in the presence of1,1'-carbonyldiimidazole to afford the corresponding N,N-dimethylamides in good to excellent yields.

A facile and efficient protocol for the synthesis of amides has been developed in the absence of transition metals. The reaction was performed with a catalytic amount of n-Bu4NI and aqueous TBHP as an oxidant. Various alcohols with N,N-disubstituted formamides were examined to furnish the desired products in good yields.

A carbon-monoxide-free aminocarbonylation of various N-substituted formamides with aryl iodides and aryl bromides using palladium acetate and Xantphos is described. The developed methodology is applicable for a wide range of formamides and aryl halides containing different functional groups furnishing good to excellent yield of the corresponding products. N-substituted formamides are used as an amide source wherein a Vilsmeier-type intermediate plays a major role, thus eliminating the need of toxic carbon monoxide gas.

The formation of intramolecular hydrogen bonds has a very pronounced effect on molecular structure and properties. We study both aspects in detail with the aim of enabling a more rational use of this class of interactions in medicinal chemistry. On the basis of exhaustive searches in crystal structure databases, we derive propensities for intramolecular hydrogen bond formation of five- to eight-membered ring systems of relevance in drug discovery. A number of motifs, several of which are clearly underutilized in drug discovery, are analyzed in more detail by comparing small molecule and protein-ligand X-ray structures. To investigate effects on physicochemical properties, sets of closely related structures with and without the ability to form intramolecular hydrogen bonds were designed, synthesized, and characterized with respect to membrane permeability, water solubility, and lipophilicity. We find that changes in these properties depend on a subtle balance between the strength of the hydrogen bond interaction, geometry of the newly formed ring system, and the relative energies of the open and closed conformations in polar and unpolar environments. A number of general guidelines for medicinal chemists emerge from this study

(Formula Presented) The nickel and phosphite catalytic system with sodium methoxide enables a very efficient aminocarbonylation reaction to be performed between aryl iodides or bromides and N,N-dimethylformamide (DMF). Phosphite ligand 1, which is very st

The barriers to rotation about the amide C-N bond in a series of ortho-substituted N,N-dimethyl and N,N-diethylbenzamides have been compared.It has been stated that for most of substituents, namely CH3, Cl, Br, I and NO2, the rates of rotation in both series of compounds are identical within the accuracy of measurement (kEt/kMe ca.1).The remaining compounds (F, CN, CH3) show a higher rate of rotation in the series of diethylbenzamides (kEt/kMe ca.1,5).An exception are the OH derivatives in which the internal H-bond is present and because of that the barrier to rotation is lowered and the kEt/kMe ratio raised up to 2.3.