Crude oils and source rocks from the northern and offshore Niger Delta basin, Nigeria, have been characterized by gas chromatography-mass spectrometry in terms of their origin and thermal maturity based on the distribution of chrysene and its derivatives. The crude oils and source rocks were characterized by the dominance of chrysene over benzo[a]anthracene. 3-methylchrysene predominated over o...

A series of 1,4-disubstituted-3,4-dihydroisoquinoline derivatives designed as tubulin polymerization inhibitors were synthesized. Their cytotoxic activities against the CEM leukemia cell line were evaluated. Most of them displayed moderate cytotoxic activities, and compounds 21 and 32 showed good activities with IC50 of 4.10 and 0.64 μM, respectively. The most potent compound 32 was further con...

We developed a 1,3-dipolar cycloaddition reaction of azomethine imines with terminal alkynes catalyzed by group 11 metal amides to provide N,N-bicyclic pyrazolidinone derivatives. This reaction afforded the cycloadducts in a unique 5,7-disubstituted manner. Furthermore, we succeeded in applying this catalysis to asymmetric reactions, and the desired heterocycles were produced in high yields wit...

A strategy based on Pd-mediated ring closure of 1,2-disubstituted indoles containing an unactivated olefin leading to indole-1,2-fused 8- and 9-membered rings has been developed for the identification of new and potential scaffolds for apoptosis. A large number of fused indole derivatives containing an endocyclic double bond were synthesized using this robust methodology. A representative compo...

5,6,7,8-Tetrahydroquinolines and 5,6,7,8-tetrahydronaphthyridines with appended trifluoromethyl groups are valuable chemotypes in medicinal chemistry due to the presence of a partially-saturated bicyclic ring and metabolically-stable CF(3) group. (1)H NMR studies were used to optimize the preparation of such compounds, using a three-step/one-pot procedure, to provide novel 2,6-disubstitued deri...

[structure: see text] A dyad of eosin and tris(2,2'-bipyridine)Ru(II) was prepared, and its photophysical properties were investigated. The photosensitization of eosin is greatly enhanced by introduction of tris(2,2'-bipyridine)Ru(II), which is verified via photooxygenation of anthracene derivatives. The electron-transfer mechanism of photosensitization is also discussed.

We reported in this work the preparation of novel 1,4-disubstituted-1,2,3-triazoles derivatives from Dglucose and D-fructose and their in vitro antibacterial activity against Mycobacterium tuberculosis were evaluated. The chemical synthesis was performed based on the 1,3-dipolar cycloaddition reaction, and antimicrobial activity was determined based on Resazurin Microtiter Assay against Mycobac...

A convenient and efficient method for the constructions of 3-spirooxindole derivatives or 3,3'-disubstituted oxindoles has been developed from one-pot reactions of isatins, hydrazides or aromatic amines, 2-(bromomethyl)acrylic ester and tin powder in the presence of a catalytic amount of Brønsted or Lewis acid. The method avoids the use of toxic stannanes and allows easy operation. It is also p...

Ball milling was exploited to prepare a substituted proline building block by mechanochemical nucleophilic substitution. Subsequently, the mechanocoupling of hindered proline amino acid derivatives was developed to provide proline-proline dipeptides under solvent-free conditions. A deprotection-cyclization sequence yielded the corresponding diketopiperazines that were obtained with a high stere...