Ruthenium-Catalyzed Self-Coupling of Secondary Alcohols.

A simple catalytic method for self-coupling of secondary alcohols leading to the synthesis of β-branched ketones under mild conditions is reported. Well-defined ruthenium pincer complex catalyzed the reactions. Optimization studies revealed that sodium -butoxide is an appropriate base for this transformation.

Direct Synthesis of Aldoximes: Ruthenium-Catalyzed Coupling of Alcohols and Hydroxylamine Hydrochloride.

A catalytic method for the direct synthesis of oximes from alcohols and hydroxyl amine hydrochloride salt is reported. The reaction is catalyzed by a ruthenium pincer catalyst, which oxidizes alcohols involving amine-amide metal-ligand cooperation, and the in situ formed aldehydes condense with hydroxyl amine to deliver the oximes. Notably, the reaction requires only a catalyst and base; water and liberated hydrogen are the only byproducts, making this protocol attractive and environmentally benign.

Ruthenium-Catalyzed Selective α-Alkylation of β-Naphthols using Primary Alcohols: Elucidating the Influence of Base and Water.

Functionalized arenes and arenols have diverse applications in chemical synthesis and material chemistry. Selective functionalization of arenols is a topic of prime interest. In particular, direct alkylation of arenols using alcohols is a challenging task.

Cobalt-catalysed [1,2]-Wittig rearrangement of ethers to secondary alcohols.

Stable ethers are successfully transformed into secondary alcohols C-O bond activation using a simple cobalt pincer catalyst. Mechanistic studies indicate the involvement of radical pairs, and their sequential recombination and the subsequent hydrolysis results in the formation of secondary alcohols.

Ruthenium-catalysed α-prenylation of ketones using prenol.

Prenol and isoprenoids are common structural motifs in biological systems and possess diverse applications. An unprecedented direct catalytic prenylation of ketones using prenol is attained. This C-C bond formation reaction requires only a ruthenium pincer catalyst and a base, and HO is the only byproduct.

A Boron-Nitrogen Double Transborylation Strategy for Borane-Catalyzed Hydroboration of Nitriles.

Organoborane-catalyzed hydroboration of nitriles provides ,-diborylamines, which act as efficient synthons for the synthesis of primary amines and secondary amides. Known nitrile hydroboration methods are dominated by metal catalysis. Simple and metal-free hydroboration of nitriles using diborane [H-B-9-BBN] as a catalyst and pinacolborane as a turnover reagent is reported.

Base-Catalyzed Traceless Silylation and Deoxygenative Cyclization of Chalcones to Cyclopropanes.

Development of simple synthetic methods from readily available compounds to complex products is of utmost interest in modern synthesis. Catalytic synthesis of cyclopropanes is important for diverse chemical applications. We present a method for the transformation of readily accessible α,β-unsaturated ketones (chalcones) to cyclopropanes.

Catalytic Hydrogenation of Epoxides to Alcohols.

Atom-economical catalytic reactions are a highly enticing strategy because all atoms of the starting materials are incorporated into the products. Catalytic hydrogenation of epoxides to alcohols is an attractive and alternative protocol to other synthetic methodologies for the synthesis of alcohols from alkenes. In the last two decades, catalytic hydrogenation of epoxides to alcohols has made remarkable progress in chemical synthesis.

Manganese(I) Catalyzed Alkenylation of Phosphine Oxides Using Alcohols with Liberation of Hydrogen and Water.

Herein, a catalytic cross-coupling of methyldiphenylphosphine oxide with arylmethyl alcohols leading to the alkenylphosphine oxides is reported. A manganese pincer catalyst catalyzes the reactions, which provides exclusive formation of -alkenylphosphine oxides. Mechanistic studies indicate that reactions proceed via aldehyde intermediacy and the catalyst promotes the C═C bond formation.

Ruthenium(ii)-catalysed 1,2-selective hydroboration of aldazines.

Herein, an efficient and simple catalytic method for the selective and partial reduction of aldazines using ruthenium catalyst [Ru(p-cymene)Cl] (1) has been accomplished. Under mild conditions, aldazines undergo the addition of pinacolborane in the presence of a ruthenium catalyst, which delivered N-boryl-N-benzyl hydrazone products. Notably, the reaction is highly selective, and results in exclusive mono-hydroboration and desymmetrization of symmetrical aldazines.

Manganese(I) Catalyzed α-Alkenylation of Amides Using Alcohols with Liberation of Hydrogen and Water.

Herein, unprecedented manganese-catalyzed direct α-alkenylation of amides using alcohols is reported. Aryl amides are reacted with diverse primary alcohols, which provided the α,β-unsaturated amides in moderate to good yields with excellent selectivity. Mechanistic studies indicate that Mn(I) catalyst oxidizes the alcohols to their corresponding aldehydes and also plays an important role in efficient C═C bond formation through aldol condensation.

Direct Catalytic Symmetrical, Unsymmetrical N,N-Dialkylation and Cyclization of Acylhydrazides Using Alcohols.

Herein, direct N,N-dialkylation of acylhydrazides using alcohols is reported. This catalytic protocol provides one-pot synthesis of both symmetrical and unsymmetrical N,N-disubstituted acylhydrazides using an assortment of primary and secondary alcohols with remarkable selectivity and excellent yields. Interestingly, the use of diols resulted in intermolecular cyclization of acylhydrazides, and such products are privileged structures in biologically active compounds.

Cobalt-catalysed selective synthesis of aldehydes and alcohols from esters.

Efficient and selective reduction of esters to aldehydes and alcohols is reported in which a simple cobalt pincer catalyst catalyses both transformations using diethylsilane as a reductant. Remarkably, the reaction selectivity is controlled by the stoichiometry of diethylsilane.

Cobalt-Catalyzed Acceptorless Dehydrogenation of Alcohols to Carboxylate Salts and Hydrogen.

The facile oxidation of alcohols to carboxylate salts and H is achieved using a simple and readily accessible cobalt pincer catalyst (NNNCoBr). The reaction follows an acceptorless dehydrogenation pathway and displays good functional group tolerance. The amine-amide metal-ligand cooperation in cobalt catalyst is suggested to facilitate this transformation.

KOtBu-Catalyzed Michael Addition Reactions Under Mild and Solvent-Free Conditions.

Designed transition metal complexes predominantly catalyze Michael addition reactions. Inorganic and organic base-catalyzed Michael addition reactions have been reported. However, known base-catalyzed reactions suffer from the requirement of solvents, additives, high pressure and also side-reactions.

Ruthenium-Catalyzed Selective Hydrogenation of Epoxides to Secondary Alcohols.

A ruthenium(II)-catalyzed highly selective Markovnikov hydrogenation of terminal epoxides to secondary alcohols is reported. Diverse substitutions on the aryl ring of styrene oxides are tolerated. Benzylic, glycidyl, and aliphatic epoxides as well as diepoxides also underwent facile hydrogenation to provide secondary alcohols with exclusive selectivity.

Manganese(I)-Catalyzed Cross-Coupling of Ketones and Secondary Alcohols with Primary Alcohols.

Catalytic cross-coupling of ketones and secondary alcohols with primary alcohols is reported. An abundant manganese-based pincer catalyst catalyzes the reactions. Low loading of catalyst (2 mol %) and catalytic use of a mild base (5-10 mol %) are sufficient for efficient cross-coupling.

Manganese(I)-Catalyzed α-Alkenylation of Ketones Using Primary Alcohols.

A simple protocol of manganese catalyzed selective α-alkenylation of ketones using primary alcohols is reported. The reactions proceeded well with a low loading of catalyst (0.3 mol %).

Ruthenium(ii)-catalysed direct synthesis of ketazines using secondary alcohols.

Direct one-pot synthesis of ketazines from secondary alcohols and hydrazine hydrate catalyzed by a ruthenium pincer complex is reported, which proceeds through O-H bond activation of secondary alcohols via amine-amide metal-ligand cooperation in the catalyst. Remarkably, liberated molecular hydrogen and water are the only byproducts.

Catalytic Cross-Coupling of Secondary Alcohols.

Herein, an unprecedented ruthenium(II) catalyzed direct cross-coupling of two different secondary alcohols to β-disubstituted ketones is reported. Cyclic, acylic, symmetrical, and unsymmetrical secondary alcohols are selectively coupled with aromatic benzylic secondary alcohols to provide ketone products. A single catalyst oxidizes both secondary alcohols to provide selectively β-disubstituted ketones to broaden the scope of this catalytic protocol.

Ruthenium-catalyzed selective α-deuteration of aliphatic nitriles using DO.

Selective catalytic α-deuteration of aliphatic nitriles using deuterium oxide as a deuterium source is reported. A PNP-ruthenium pincer complex catalyzed the α-deuteration of aliphatic nitriles including acetonitrile. Efficient deuteration occurred with a low catalyst load (0.

Iron-Catalyzed Selective Etherification and Transetherification Reactions Using Alcohols.

Simple and readily available iron(III) triflate turned out to be a cheap, environmentally benign, and efficient catalyst for the direct etherification of alcohols. The use of ammonium chloride as an additive (5 mol %, 1 equiv relative to catalyst) suppressed the side reactions completely and ensured the selective ether formation even on challenging substrates containing electron-donating substituents. This method allows the selective synthesis of symmetrical ethers from benzylic secondary alcohols and unsymmetrical ethers directly from secondary and primary alcohols.

Ruthenium-Catalyzed Urea Synthesis by N-H Activation of Amines.

Activation of the N-H bond of amines by a ruthenium pincer complex operating via "amine-amide" metal-ligand cooperation is demonstrated. Catalytic formyl C-H activation of N,N-dimethylformamide (DMF) is observed in situ, which resulted in the formation of CO and dimethylamine. The scope of this new mode of bond activation is extended to the synthesis of urea derivatives from amines using DMF as a carbon monoxide (CO) surrogate.

Ruthenium-catalysed multicomponent synthesis of borasiloxanes.

We present the selective atom economical synthesis of borasiloxanes using a multi-component approach directly by the one-pot ruthenium catalysed reaction of boranes, silanes and water.