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An efficient synthetic method has been developed to obtain chemical weapons convention (CWC)-related O,O′-dialkyl-N,N-dialkylphosphoramidates from dialkylphosphites using inorganic reagents (CuCl2 and Cs2CO3) at room temperature.

Six-membered heterocyclic compounds containing oxyg en such as 2H-pyran and 4H-pyrans constitute an imp ortant class of biologically active natural and synthetic products, playing a fundamental role in bioorganic chemistry and continuing to attract interest. Pyrans and their analogues occupy prime position in Bioorganic chemistry due to their diverse applications. In this review, up to date information about the developments, explorationof new methodologies and varied biological activities of pyran analogues was discussed.

A one-pot process has been developed for preparing alkaloid-like tricyclic skeletons by employing an Ugi reaction, an acid mediated ipso-cyclization and an aza-Michael addition. The transformation is operationally simple and provides products in a diastereo- and regioselective manner with good-to-excellent yields.

New treatments are desperately required to combat increasing rate of dengue fever cases reported in tropical and sub-tropical parts of the world. Among the ten proteins (structural and non-structural) encoded by dengue viral genome, NS2B-NS3 protease is an ideal target for drug discovery. It is responsible for the processing of poly protein that is required for genome replication of the virus. Moreover, inhibitors designed against proteases were found successful in Human Immuno-deficiency Virus (HIV) and Hepatitis C Virus (HCV). Complete molecular mechanism and a survey of inhibitors reported against dengue protease will be helpful in designing effective and potent inhibitors. This review provides an insight on molecular mechanism of dengue virus protease and covers up-to-date information on different inhibitors reported against dengue proteases with medicinal chemistry perspective.

It is found that the configuration of the double bond formed during the RCM depends on the order of the synthetic route.

A protocol is presented for the synthesis of enantiopure THIQs from DHIQs, isocyanides, and aromatic or aliphatic carboxylic acids.

We demonstrate a new synthetic strategy to cyclophanes containing thiophene and indole moieties via Grignard addition, Fischer indolization and ring-closing metathesis as key steps.

The one-pot chlorination of phosphites (I) and subsequent displacement of chloride by fluoride gives access to fluorophosphates (II) under mild conditions.

Several substituted 2′-amino-biphenyl-2-ols were synthesized. The mild and TM-free double functionalization: nitration and cycloetherification of 2′-amino-biphenyl-2-ols have been achieved for the synthesis of functionalized 4-nitro-dibenzofurans utilizing NaNO2 in TFA and water. Interestingly, nitration of phenol ring was observed along with the dibenzofuran ring formation in the one-pot synthesis. The position of the nitro group in several dibenzofurans is also established by X-ray crystal structure studies. Further functionalization of the obtained 4-nitro-dibenzofurans has been carried into 3-nitro-terphenyl-2-ol, novel benzofuro-indoles, and amino-dibenzofurans. The mechanistic understanding on double functionalization of 2′-amino-biphenyl-2-ols suggests that reaction proceeds by a combination of nitration of the phenol ring followed by Sandmeyer reaction for dibenzofuran ring formation.

We have developed a simple methodology to transform cis-syn-cis-triquinane derivative 2 into the diindole based macrocycle 6 involving Fischer indolization and ring-closing metathesis (RCM). Various spiro-polyquinane derivatives have been assembled via RCM as a key step.

The five membered heterocycles isoxazolines are considered as important class of compounds in bioorganic and medicinal chemistry. They were treated as useful intermediates for transforming to large number of bioactive molecules. These classes of compounds were known to have varied biological activities. In this review, critical discussion has been made on synthetic methodologies developed, utility as building blocks for the synthesis of bioactive molecules and medicinal applications of isoxazoline systems.

The CuI-nanoparticles catalyze the inter- and intramolecular N-arylation of various amines using vitamin E analogues (TPGS) as amphiphiles in water.

The first CuI-nanoparticle catalyzed ligand free synthesis of N-aryl amides from aryl halides and arylamides/cyclic amides has been developed. This methodology is further extended for the synthesis of nitrogen heterocycles such as benzimidazole, and quinazolinone via intermolecular amidation reaction followed by cyclization. TEM images of the CuI-NP catalyst showed spherical, well-dispersed particles which provide large surface area for reactivity and have good recyclability.

Malaria has emerged as a major health problem worldwide after the appearance of resistant strains of Plasmodium falciparum to the most of antimalarial drugs. The development of resistance by the parasite against first line as well as second line antimalarial drugs has drawn attention to develop new drugs to alleviate the disease burden. Therefore, there is a great need for new antimalarial drugs with improved attributes over older therapies. This review is primarily addressed to description of the recent advances in the synthesis of heterocyclic compound as antimalarial agents which can facilitate the development of more potent and effective antimalarial agents.

We report the use of magnetic nano Fe3O4 as a mild heterogeneous catalyst for the aminolysis of epoxides with amines. The approach constitutes a green method for the formation of a variety of β-amino alcohols with very high stereo- and regioselectivity under solvent-free and ambient reaction conditions. The aminolysis of chiral epoxides with amines gave the corresponding chiral β-amino alcohols with complete inversion of stereochemistry. The magnetic nano Fe3O4 catalyst can be easily recovered and recycled.

A simple and convenient approach for the synthesis of unsymmetrical diaryl chalcogenides (Te, Se, and S) has been developed by copper-catalyzed cross-coupling reaction of organoboronic acid with diaryl dichalcogenide in ethanol using NaBH4 in air or oxygen. The present methodology is highly practical for the synthesis of unsymmetrical diaryl tellurides with various functionalities such as –NO2, –F, –Br, and –COOH that have been obtained in good to excellent yields. Methodology is also effective for the synthesis of unsymmetrical diaryl selenides and sulfides. Moreover, symmetrical diaryl selenides have also been obtained from arylboronic acids using elemental selenium powder under optimized reaction conditions. The use of NaBH4 is the key for the development of milder reaction conditions, which enable the construction of unsymmetrical diaryl chalcogenides from boronic acid substrates in ethanol at room temperature.

Fischer indole cyclization in a low melting mixture of L-tartaric acid and N,N′-dimethylurea provides the expected isomer (III) together with unexpected high amounts of the unusual isomer (IV).

Nitrile imines are considered as the versatile reactive intermediates and are recognized as a linear-type 1,3-dipoles extensively used in 1,3-dipolar cycloaddition reactions for constructing biologically potent five membered heterocycles. This review article comprises the brief history, up to date information about the various methods employed for the generation, stability, reactivity and synthetic applications of nitrile imines. The stereochemistry of the products formed with the use of nitrile imines and biological activity associated with the cycloadducts formed was also presented.

KOtBu In DMSO can be efficiently used for the synthesis of unsymmetrical diaryl sulfides and selenides from diaryl dichalcogenides and aryl bromides.

Mild and efficient esterification of alkylphosphonic acids using primary alcohols, iodine, imidazole and polymer-bound triphenylphosphine is developed.

Claisen condensation of tetrahydrocycloheptaindolones (I) with ethyl formate (II) yields the intermediates (III) which in one-pot addition reactions with appropriate nucleophiles afford a library of new title indoles.

Podophyllotoxin (1) has been known to possess anti-tumor activity and is still considered an important lead for research and development of antineoplastic agents. Derivatives of podophyllotoxin, namely etoposide (2), etopophos (3) and teniposide (4) have been developed and are currently used in clinic for the treatment of a variety of malignancies. These agents are also used in combination therapies with other drugs. Due to the drug resistance developed by cancer cells as well as side effects associated with the use of these agents in clinic, the search for new effective anticancer analogues of podophyllotoxin remains an intense area of research. The structural complexity of podophyllotoxin, arising from the presence of four stereogenic carbons in ring C has restricted most of the structural activity relationship (SAR) studied by derivatization of the parent natural product rather than by de novo multi-step chemical synthesis. These issues provide strong impetus to a search for analogues of 1 with simplified structures, which can be accessible via short synthetic sequences from simple starting materials. Even if such initial compounds might have diminished cytotoxic potencies compared with the parent cyclolignan, the ease of preparation of carefully designed libraries of analogues would lead to more informative SAR studies and expeditious structure optimization. In this regard, during the last two decades considerable efforts have been made to synthesize aza- analogs of podophyllotoxin, i. e. aza-podophyllotoxins, with hetero atoms at different positions of the podophyllotoxin skeleton, while keeping the basic podophyllotoxin structure. Recently, there have been significant efforts towards the convenient synthesis of aza-analogs of 1. The use of multicomponent reactions (MCRs) and the synergies of ultrasound and microwave irradiations have increased the synthetic speed and variety of azapodophyllotoxins which are and will be available to be tested against a diverse population of carcinomas and other diseases. It has been reported that several aza-podophyllotoxins retain a great fraction of the cytotoxicity associated with the parent lignan. This review focuses on the strategies towards synthesis of various aza-podophyllotoxin analogues and their biological activities.

Novel arylamino alcohols were synthesized and these alcohols were used to prepare 12 novel N-(2-hydroxy-ethyl)-2,3-didehydroazapodophyllotoxins, in one step, by simple reflux in ethanol. Isolated yields in the range of 50–70% were obtained.

A new class of fused oxazoloquinoline derivatives was synthesized starting from 2-bromo-1-phenylethanones 1a-b through multi-step reactions. The newly synthesized compounds were evaluated for their in vitro antibacterial against Escherichia coli (ATTC-25922), Staphylococcus aureus (ATTC-25923), Pseudomonas aeruginosa (ATCC-27853) and Klebsiella pneumoniae (recultured) and antituberculosis activity against Mycobacterium tuberculosis H37Rv (ATCC 27294). Preliminary results indicated that most of the compounds demonstrated very good antibacterial and antituberculosis activities which are comparable with the first line drugs. Compounds 6a, 6c, 6g, 6j, 6k and 6n emerged as the lead antitubercular agents with MIC, 1 μg/mL and 99% bacterial inhibition while eight compounds, viz., 5a, 15k, 6a, 6c, 6g, 6j, 6k and 6n were found to be more potent than INH (MIC: 1.5 μg/mL) with MIC 1 μg/mL.

Nitrile oxides generated in situ by the oxidative dehydrogenation of aldoximes (2) react with alpha -cyanocinnamate esters (1) to afford ethyl 3,5-diarylisoxazole-4-carboxylates (4) in good yield. The esters (4) were tested for their antimicrobial activity.

The acetyl acetone 3 reacts smoothly with the nitrile imines 2 generated in situ by the catalytic dehydrogenation of diphenyl hydrazones 1 using chloramine-T to afford regioselective cycloadducts 5,6 in 59-78% and 6-8% yields respectively.

Nitrile oxides (2) isolated from the oxidative dehydrogenation of aldoximes (1) by chloramines-T react with acetyl acetone (3) to afford 4-acetyl-3-aryl-5-methyl isoxazoles (5) in good yield. All new compounds were characterized by IR, 1H NMR, 13C NMR, MS studies and elemental analysis.