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An efficient copper-mediated etherification of inert C–H bonds of (hetero)arenes with reagent-amounts of alkoxysilanes and alkanols has been developed using (2-aminophenyl)pyrazole (2-APP) as a removable directing group. The reaction is scalable, rapidly proceeds under an open atmosphere, and tolerates diverse functional groups to provide alkyl aryl ethers in high yields (up to 87%). As an application, the formal synthesis of anti-emetic drug metoclopramide is accomplished.

Reaction of 1,3-disubstituted isobenzofurans (IBFs) with selenium dioxide in tetrahydrofuran (THF) at room temperature led to the formation of 1,2-diaroyl/(heteroaroyl)benzenes in good to excellent yields.

Catalytic addition of chiral phosphine, that is, (R)- or (S)-SITCP, to an α-substituted allene ester generated a zwitterionic dipole. Under optimized reaction conditions, this dipole could engage isatine-derived N-Boc-ketimines in a novel mode of [3+2] annulation reaction. Pyrrolinyl spirooxindoles are thus afforded in high yields and with excellent enantioselectivities. The unprecedented annulation reaction successfully facilitated the construction of sp(3) -rich and highly substituted 3,2'-pyrrolidinyl spirooxindoles supporting many chiral centers.

A versatile diastereoselective Friedel-Crafts alkylation reaction of heteroaryl systems with a cyclic enecarbamate for the preparation of 5-heteroaryl-substituted proline analogues in good yields has been developed. These heterocyclic tethered cyclic amino acid building blocks constitute important structural motifs in many biologically active molecules. The impact of the substitution on proline cis/trans isomerization was explored by carrying out solution conformational studies by NMR on 5-furanyl-substituted proline-containing peptides. Conformational analysis revealed that the peptide bond is constrained in an exclusively trans conformation.

A new condensation reaction of ethylene-1,2-diamines or o-phenylenediamines and aromatic aldehydes with TMSCN as a cyanide-pronucleophile is documented. The reaction proceeds through a tandem sequence of desilylation, Strecker reaction, amidine-forming cyclization and dehydrogenative aromatization, and provides a straightforward synthetic route to access synthetically and biologically important motifs, 3-aryl substituted 2-aminopyrazines and 2-aminoquinoxalines. DBU with its unique function and rate-accelerating effect has made it possible to realize a reaction that involves several C–C/N/Si bond forming/breaking events. Interestingly, the protocol has enabled the desired tandem pathway, switching exclusively from usual transformations.

affording a wide range of dihydropyrrolyl spirooxindoles with excellent enantioselectivities

A novel multi-component synthesis of dithiocarbonates (xanthates) in a single pot has been accomplished under very mild conditions. The S-alkyl part in the products contains a functional group. An alcohol and an activated vinyl compound that is capable of acting as Michael acceptor are mixed together in carbon disulfide in the presence of a tertiary amine at room temperature when the title compound is formed. The method is very much successful with primary and secondary alcohols in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) as catalyst. The yields are excellent. The Morita-BaylisHillman reaction derived allylic alcohols however behave a little differently, and the method has been utilized to prepare trisubstituted alkenes possessing thioether moiety and some biologically important thiochromenes.

Scaffold diversity is a crucial feature of compound collections that has a huge impact on their success in biological screenings. The synthesis of highly complex and diverse scaffolds, which could be based on natural products, for example, is an arduous task that requires expertise in various aspects of organic synthesis and structural analysis. This challenge has been addressed by a number of synthesis designs, which employ natural products as a source of scaffold diversity, transform suitably designed common intermediates into various molecular frameworks, or entail highly concise synthetic routes to a number of distinct and complex scaffolds. In this Minireview, we highlight recent synthetic developments towards the construction of diverse and complex scaffolds and the application of the resulting compound collections in drug and probe discovery.

A systematic study on the regioselective cyclization of benzene- and naphthalene-based unsymmetrical diols with HBr (33 %) in acetic acid at room temperature led to the formation of annulation products. By using this method, synthesis of a wide variety of anthracene, tetracene and naphtho[b]thiophene analogues was achieved in good to excellent yields. By employing HBr (33 %) in acetic acid as a catalyst for regioselective cyclization of unsymmetrical diols was very facile and devoid of commonly encountered dihydroisobenzofuran formation.

A direct regioselective C3-H arylation of pyrido[1,2-a]pyrimidin-4-ones using Pd(OAc)2 as the catalyst in the presence of Ag2CO3 as promotor is developed.

HMBTB is used as a crystalline and stable reagent for the bromination of electron rich arenes as well as imidazole, olefins, alkynes, and carbonyl compounds.

A one pot synthesis of 1H-benzo[g]indoles, tetrahydrobenzo[h]quinolines, and naphtho[1,2-b]azepines from 2-alkynyl benzaldehydes and cyclic amino acids is reported. The salient feature of the strategy involves formation of three new bonds (one CN and two CC bonds) by a metal-free decarboxylation/cyclization/one-carbon ring expansion sequence in one pot.

Quasi-spherical CuCr2O4 spinel nanoparticle catalysts (5-35 nm) are prepared via urea assisted co-precipitation from a stoichiometric aqueous solution of Cu(NO3)2 and Cr(NO3)3 (110 °C, 3 h) followed by calcination of the dried mixed hydroxide precipitate (1.

An efficient Pd-catalyzed arylation process of enol-tosylates derived from 1,3-diones or barbituric acid with boronic acids is developed to allow the synthesis of the title compounds in generally good yields.

The title procedure is investigated for various educts bearing different ligands at the amide nitrogen.

The magnetic and electronic properties of the title compound are characterized by synchrotron powder XRD, magnetic measurements, and DFT calculations.

A simple one-pot protocol for the Pd-catalyzed oxidative annulation of internal alkynes with indoles to form pyridooxindole derivatives is presented.

A heterogeneous montmorillonite K-10-supported palladium triphenylphosphine catalyst is reported for the Suzuki–Miyaura cross-coupling reaction at room temperature. A library of electronically diverse aryl bromides and arylboronic acids underwent the cross-coupling reaction at very good rates in aqueous solvent. The reusability of the catalyst was also examined and it was found to be effective up to three catalytic cycles. Copyright © 2014 John Wiley & Sons, Ltd.

The title compounds are prepared by solution combustion synthesis from aqueous solutions of stoichiometric amounts of M(NO3)2 (M: Ni, Co, Mn), NaNO3, NH4H2PO4, and glycine (200—300 °C, 10 min), followed by calcination of the foamy product (400—700 °C, 3 h).

A pathway of desilylative activation of TMSCN as a functional isonitrile equivalent, and DABCO–THF as an appropriate system for activation in a chemoselective Strecker–Ugi type reaction, has rendered ethyl glyoxalate and various heterocyclic-2-amidines as feasible substrates, and afforded the successful synthesis of 3-amino-2-carboxyethyl substituted fused imidazoles as useful building blocks. This class of functional scaffold has provided, via construction of the fused pyrimidinone motif, the synthesis of biologically important C8–N9 annulated purines, adenines and their oxo/thio analogs. This new approach is convenient and flexible for the preparation of versatile purine-condensed heterocycles.

La3GeSb0.31Se7 and La3SnFe0.61Se7 are prepared by solid state reaction of stoichiometric mixtures of the elements (evacuated silica tubes, 800 °C, 4 d).

Application of the alkyl epoxy ester ethyl 3-methyloxirane-2-carboxylate gives a complex reaction mixture.

Reaction of 1-methyl-3,4-dihydro-β-carboline 1 with methyl glycidate 4 gave the novel tetracyclic conjugated γ-lactam, 2-methylpyrrolo[1′,2′:1,2]pyrido[3,4–6]indol-3-one 5. The same compound 5 was obtained in higher yield when 1 was treated with methyl 2-methoxyacrylate 7. Sodium borohydride treatment of 5 resulted in the cleavage of lactam to yield the unexpected alcohols 8 and 9.

The strategy allows the preparation of a library of benzodiazepines with potential pharmaceutical and biological activity.

Optimum reaction conditions are examined for the three-component one-pot synthesis of α-aminophosphonates of type (IV).

4-Oxo-4H-1-benzopyran-3-carboxaldehyde (chromone-3-carboxaldehyde or 3-formylchromone) 1 is an important biologically active compound. It can serve as a precursor in the synthesis of a wide range of heterocyclic systems having chromone moiety, many of which exhibit broad spectrum of biological activities such as anti-mutagenisity, cytotoxicity, thymidine phosphorylase inhibitor, and anti-HIV activity. During the last decade, the title compound was studied extensively. The review presents an overall survey of the synthesis, chemical reactivity, and biological activities of 4-oxo-4H-1-benzopyran-3-carboxaldehydes and some of its derivatives.

This straightforward and general method provides access to mono-, bis- and tris-heteroarylphthalides through triflic acid-mediated Friedel-Crafts phthalidations.

This review contains extensive application of anion sensing ability of salicylidene type Schiff bases and their reduced forms having various substituents with respect to phenolic OH group. Some of these molecular systems behave as receptor for recognition or sensing of various anions in organic or aqueous-organic binary solvent mixture as well as in the solid supported test kits. Development of Schiff base or reduced Schiff base receptors for anion recognition event is commonly based on the theory of hydrogen bonding interaction or deprotonation of phenolic -OH group. The process of charge transfer (CT) or inhibition of excited proton transfer (ESIPT) or followed by photo-induced electron transfer (PET) lead to naked-eye color change, UV-vis spectral change, chemical shift in the NMR spectra and fluorescence spectral modifications. In this review we have tried to discuss about the anion sensing properties of Schiff base or reduced Schiff base receptors.

The title compounds are prepared by reaction of stoichiometric mixtures of the elements (evacuated silica tube, 1.

The presence of electron donating alkyl groups in starting material (I) is key to the success of the reaction.

The new title compounds are synthesized by solid state reaction of the elements (vacuum sealed quartz tubes, 1073 K, 100 h) and characterized by single crystal XRD, UV/VIS/near-IR spectroscopy, electrical conductivity measurements, and DFT calculations.

A new facile stereoselective method for the synthesis of trisubstituted E/Z olefinic thio compounds and 2H-thiochromenes is accomplished.