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Synthesis of α,β-unsaturated-γ-lactams continue to attract attention due to the importance of this structural motif in organic chemistry. Herein, we report the development of a visible-light-induced excited-state copper-catalyzed [4 + 1] annulation reaction for the preparation of a wide range of γ-H, -OH, and -OR-substituted α,β-unsaturated-γ-lactams using acrylamides as the 4-atom unit and aroyl chlorides as the 1-atom unit. This modular synthetic protocol features mild reaction conditions, broad substrate scope, and high functional group tolerance. The reaction is amenable to late-stage diversification of complex molecular architectures, including derivatives of marketed drugs. The products of the reaction can serve as versatile building blocks for further derivatization. Preliminary mechanistic studies suggest an inner-sphere catalytic cycle involving photoexcitation of the Cu(BINAP) catalyst, single-electron transfer, and capture of radical intermediates by copper species, followed by reductive elimination or protonation to give the desired γ-functionalized α,β-unsaturated-γ-lactams.

The scope of biomimicking vanadium bromoperoxidase in producing bromonium ions and its further utilisation in conducting oxidative bromination or cleavage of various organic molecules has been described in this review.

Nature has established a broad spectrum of methods to introduce halogen atoms in organic compounds. Recent developments have revealed that haloperoxidases are one of the major sources responsible for incorporating bromines to produce bromoorganics in nature. Pioneering studies of numerous researchers have unravelled the details of haloperoxidases, mainly vanadium dependent enzyme bromo- and iodo-peroxidases, including reaction mechanism, kinetics and especially biomimicking studies. In this review, we initially have described the scope of biomimicking vanadium bromoperoxidase in producing the bromonium ion and its further utilisation in conducting oxidative bromination or cleavage of various organic molecules. Moreover, by biomicmicking, the synthesis of OATB and the synthetic utility of various organic ammonium tribromides (OATBs) have been discussed. Among such OATBs

Heterocycles represent one of the largest groups of organic moieties with significant medicinal, chemical, and industrial applications. Herein, we report the discovery and development of visible-light-induced, synergistic excited-state copper catalysis using a combination of Cu(IPr)I as a catalyst and rac-BINAP as a ligand, which produces more than 10 distinct classes of heterocycles. The reaction tolerates a broad array of functional groups and complex molecular scaffolds, including derivatives of peptides, natural products, and marketed drugs. Preliminary mechanistic investigation suggests in situ generations of [Cu(BINAP)(2)](+) and [Cu(IPr)(2)](+) catalysts that work cooperatively under visible-light irradiation to facilitate catalytic carbo-aroylation of unactivated alkenes, affording a wide range of useful heterocycles.

A hitherto unreported route for the synthesis of anthranilate esters is demonstrated using 2-nitrobenzaldehyde, malonitrile and an alcohol or amine via a metal and oxidant free multicomponent reaction (MCR) strategy. This process simultaneously installs an ester and urea or urethane functionality via CO and CN bond formations via concurrent oxidation of the aldehyde group and reduction of the nitro group involving an intramolecular redox process.

A wide variety of 3-aminocoumarins have been synthesized in large scale from the corresponding 3-acetamidocoumarins by regioselective cleavage of carbon–nitrogen bond using 70% sulfuric acid under reflux conditions. The synthesized 3-aminocoumarins were further brominated regioselectively at the 4-position of 3-aminocoumarin using BDMS as brominating agent.

An efficient protocol has been developed for the synthesis of pyridines and 1,4-dihydropyridines based on chemoselective multicomponent reactions. Using readily available aldehydes, malononitrile and primary aliphatic amines, this procedure provides a divergent but straightforward access to a wide range of fully substituted pyridines and dihydropyridines via a primary amine based chemoselective strategy. Simple reaction procedure, good yields, mild reaction conditions, applicabilility to a wide range of substrates with the aid of chemoselectivity make this present protocol more innovative than existing ones.

Fused furo- and pyrano-tetrahydropyrido[2,3-c]coumarin derivatives were synthesized using one-pot three component reactions between aromatic aldehydes, 3-aminocoumarins and cyclic enol ethers in the presence of 10 mol% hydrated ferric sulphate [Fe2(SO4)3·xH2O] in refluxing acetonitrile. The salient features of the present protocol are good yields, high diastereoselectivities, application to a wide range of substrates, using an inexpensive, readily available and recyclable catalyst and environmentally benign reaction conditions.

A new approach for the synthesis of multi-functionalized 1,5-benzodiazepines is developed starting from o-phenylenediamines, β-keto esters and aromatic aldehydes utilizing a one-pot, three-component strategy employing bromodimethylsulfonium bromide as the catalyst. The simple reaction procedure, good yields, mild reaction conditions and applicability to a wide range of substrates are some of the salient features of this protocol.

The synthesis of hitherto unreported 5-amino-7-alkoxy2-methyl-2,4-aryl-1,2-dihydro-1,6-naphthyridine-8-carbonitriles (4) was accomplished by a one-pot pseudo five-component reaction using aryl methyl ketones or alkyl methyl ketones, malononitrile, and alcohols in the presence of sodium hydroxide under reflux conditions. By following an identical reaction procedure, various 5-amino-2-methyl-2,4

2,6-Pyridinedicarboxylic acid has been found to be an effective and efficient organocatalyst for the synthesis of 1,5-benzodiazepine derivatives from o-phenylenediamine, β-ketoesters, and aromatic aldehydes by employing one-pot three-component reaction. The catalyst plays a crucial role for the regioselective C–C bond formation at the γ position of β-ketoesters. The salient features of this present protocol are simple reaction procedure, requirement of cost-effective catalyst, good yields, and applicable to a wide range of substrates.

Among organic compounds hydrocarbons are inexpensive and possibly the most abundant among natural resources. Developing strategies for selective functionalisation of inert hydrocarbon C–H bonds is one of the most ideal synthetic paths that a synthetic chemist could think of. This critical review focuses on the recent development of various directed and non-directed cycloalkylations leading to the formation of carbon–carbon (C–C) and carbon–heteroatom (C–X) bonds. Apart from various transition metal catalysed cycloalkylations, this review also covers various metal-free cycloalkylation processes.

A hitherto unreported route for the synthesis of anthranilate esters is demonstrated using 2-nitrobenzaldehyde, malonitrile and an alcohol or amine via a metal and oxidant free multicomponent reaction (MCR) strategy. This process simultaneously installs an ester and urea or urethane functionality via CO and CN bond formations via concurrent oxidation of the aldehyde group and reduction of the nitro group involving an intramolecular redox process.

An efficient protocol has been developed for the synthesis of pyridines and 1,4-dihydropyridines based on chemoselective multicomponent reactions. Using readily available aldehydes, malononitrile and primary aliphatic amines, this procedure provides a divergent but straightforward access to a wide range of fully substituted pyridines and dihydropyridines via a primary amine based chemoselective strategy. Simple reaction procedure, good yields, mild reaction conditions, applicabilility to a wide range of substrates with the aid of chemoselectivity make this present protocol more innovative than existing ones.

3-Acetamidocoumarins are converted into 3-aminocoumarins upon treatment with sulfuric acid.

Title compounds (IV) and (VI) are synthesized using an one-pot three-component coupling between 3-aminocoumarins (I), aromatic aldehydes (III) and cyclic enol ethers (II) or (V).

The facile one-pot procedure allows the synthesis of 1,5-benzodiazepines from o-phenylenediamines, aldehydes, and β-keto esters under mild reaction conditions.

The title reaction proceeds under mild conditions with high chemoselectivity and uses easily available materials.

Title compounds such as (IV), (VI), and (VIII) are prepared via a three-component reaction of o-phenylenediamine (I), aromatic aldehydes and β-ketoesters.