an efficient one pot multi component synthesis of 1, 4-polyhydroquinoline derivatives through unsymmetrical hantzsch reaction using lanthanum chloride heptahydrate (lacl3.7h2o) from an aromatic aldehyde, ethyl acetoacetate, dimedone and ammonium acetate as a nitrogen precursor in ethanol at room temperature is described. in the present work we report lanthanum chloride heptahydrate remarkably n...

Photodynamic therapy (PDT) is an effective option for the treatment of solid neoplastic tumors, as well as non-malignant diseases such as dermatological, ophthalmological and benign pathologies. PDT destroys cancer cells by photochemical generation of reactive oxygen species upon absorption of visible light by a photosensitizing agent (PS). Here, we describe the synthesis and characterization o...

Polyfluoro-substituted unsymmetrical biaryl ethers were synthesized via a novel Ni-catalyzed cross-coupling reaction of polyfluoroarenes with arylboronic acids and oxygen. The polyfluorinated arenes presumably captured the phenoxide intermediate efficiently, which made the oxygen-insertion proceed smoothly via the S(N)Ar protocol. The (18)O labeling experiment demonstrated that the oxygen intro...

Microwave dielectric heating proved to be an efficient method for the one-pot and stepwise syntheses of symmetrical and unsymmetrical naphthalenediimide derivatives of alpha-amino acids. Acid-labile side chain protecting groups are stable under the reaction conditions; protection of the alpha-carboxylic group is not required. The stepwise condensation of different amino acids resulted in high y...

Synthesis of bisfunctionalized unsymmetrical 2,2'-bipyridines 8 or their sulfonyl derivatives 12a,b are described. They were prepared via the Diels-Alder reaction of 1-methyl-4-pyrrolidin-1-yl-1,2,3,6-tetrahydropyridine (6) with 3,3'-bis(methyl- sulfanyl)-5,5'-bi-1,2,4-triazine (1). The reaction leads to the single cycloaddition product 7 which undergoes Diels-Alder reaction with cyclic enamine...

The efficient and mild copper-catalyzed synthesis of unsymmetrical diorganyl chalcogenides under ligand- and solvent-free conditions is described. The cross-coupling reaction was performed using aryl boric acids and 0.5 equiv. of diorganyl dichalcogenides (Te/Se/S) in the presence of 3 mol % of CuI and 3 equiv. of DMSO, under microwave irradiation. This new protocol allowed the preparation of s...

Novel strategies for the efficient synthesis of unsymmetrical glycosyl disulfides are reported. Glycosyl disulfides are increasingly important as glycomimetics and molecular probes in glycobiology. Sialosyl disulfides are synthesised directly from the chlorosialoside Neu5Ac2Cl, proceeding via a thiol-disulfide exchange reaction between the sialosyl thiolate and symmetrical disulfides. This meth...

An efficient one pot multi component synthesis of 1, 4-Polyhydroquinoline derivatives through unsymmetrical Hantzsch reaction using lanthanum chloride heptahydrate (LaCl3.7H2O) from an aromatic aldehyde, ethyl acetoacetate, dimedone and ammonium acetate as a nitrogen precursor in ethanol at room temperature is described. In the present work we report lanthanum chloride heptahydrate remarkably n...

Insights to the subtle reactivity patterns of hydroxy-substituted carbazoles allows the precise synthesis of unsymmetrical azatrioxa[8]circulenes by the reaction of N-benzyl-2,7-di-tert-butyl-3,6-dihydroxycarbazole with two different 1,4-benzoquinones in the presence of an oxidant (chloranil) and a Lewis acid (BF3OEt2). The unique synthetic control obtained originates from the selectivity obtai...