We report the synthesis and characterization of two diphosphine nickel complexes containing 9-borafluorene (PBFlu, 9-(diisopropylphosphino)phenyl-9-borafluorene) and 9,10-dihydroboranthrene (B2P2, 9,10-bis(2-(diisopropylphosphino)phenyl)-9,10-dihydroboranthrene) cores. Metalation of PBFlu and B2...

Two methods for preparing π-methylenecyclopropanebis(triphenylphosphine)-nickel are described: (1) the substitution of the ethylene ligand in π-ethylenebis(triphenylphosphine)nickel by methylenecyclopropane; (2) the interaction of Ni(acac)2 with diethylaluminium ethoxide in the presence of met...

The polymerization of norbornene in the presence of ethene using the Ni(PPh3)4/BF3OEt2 catalyst system has been investigated. This Ni(PPh3)4/BF3OEt2 system is highly active for the polymerization of norbornene in the presence of ethene. The products of the reaction are norbornene oligomers with ...

A simple Lewis acid, boron trifluoride etherate, was applied as novel activator towards a new nickel precursor Ni(PPh3)4 for the polymerization of norbornene. The system Ni(PPh3)4/BF3OEt2 is highly active in the polymerization of norbornene. The product obtained showed exclusively 2,3-connectivi...

The oxidative addition of benzyl chloride or bromide to tetrakis(triphenylphosphine)nickel(O) followed by carbonylation and the addition of methanol yielded methyl phenylacetate. When (R)-α-D benzyl chloride was subjected to this reaction sequence, racemic ester was obtained, probably as a resu...

In the presence of tetrakis(triphenylphosphine)nickel, fluoroalkylation reactions of benzene, furan, thiophene and pyrrole take place regioselectively, giving moderate to good yields of the corresponding fluoroalkyl derivatives.

Burning Arabian incense (Bakhour) is a common practice in the Middle East and Arabian Gulf. Although the incense generates large amounts of chemicals and air pollutants, little is known with regard to the nature of these chemicals and their potential health risks. The aim of this study is to pro...

The first syntheses of tri- and tetra-cyclic vic-disubstituted arene oxides are described. The general route to 9,10-dimethyl- and 9,10 - bis(p - chlorophenyl) - phenanthrene - 9,10 - oxide, and to 5,6 - diphenylbenzo[c]phenanthrene 5,6 - oxide, includes oxidation of the unsubstituted aromatic h...

Oxidation of chrysene with dimethyldioxirane gives a number of products including the interesting trioxide, chrysene-5,6:4b,10b:11,12-trioxide, 3. The x-ray crystallographic stucture of 3 indicates that it is a non-planar system.

Two analytical methods have been evaluated for quantitative determination of de-conjugated chrysene metabolites in fish bile. High performance liquid chromatography-fluorescence (HPLC-F) and gas chromatography–mass spectrometry (GC–MS) were compared regarding instrumental and overall limits of...

Salicylaldehyde reacts with dimethyl acetylenedicarboxylate in benzene solution to give a mixture of dimethyl o-formylphenoxymaleate, dimethyl o-formylphenoxyfumarate, 2,3-dicarbomethoxychrom - 2 - en - 4 - ol, 2,3 - dicarbomethoxychrom - 3 - en - 2 - ol, dimethyl (2,3 - dicarbomethoxychrom - 2 ...

Three coumestans, flemichapparin, medicagol and sophoracoumestan B, are synthesised by direct reaction of the analogous 2,2′-dihydroxychalcones with thallium(III) nitrate in methanol.

Several flavonoids and their biosynthetic precursor chalcones were designed and synthesized to improve the biological effects of the lead compound 2′-hydroxyflavonone against androgen receptor (AR)-dependent transcriptional stimulation. Newly synthesized chalcones 19 and 26 suppressed AR-depend...

In this paper we describe the design and synthesis of bis(Het)Aryl-1,2,3-triazole quinuclidine α7R ligands using an efficient three-step sequence including a Suzuki-Miyaura cross coupling reaction with commercially available and home-made boron derivatives. The exploration of SAR required the p...

Inokosterone, a phytoecdysone isolated from Achyranthes fauriei (Amaranthaceae), has been partially acetylated to give the 2,26-diacetate (4) which has been converted into methyl 5 - acetoxy - 4 - methylpentanoate (7), showing no apparent [α]D, and 2β - acetoxy - 3β,14α - dihydroxy - 5β - p...

Δ24/Δ25-Derivatives of 20-hydroxyecdysone were hydroborated by sodium borohydride in the presence of CuCl followed by oxidation of organoboron intermediate and deblocking of hydroxyl groups to synthesise the zoo-and phytoecdysteroid inokosterone.

The activation of C–O bonds in allylic acetates has been accelerated by carrying out the reactions in the presence of platinum complexes associated with ligands. Platinum-catalyzed allylation of aminonaphthalenes with allylic acetates leads to N-allylic aminonaphthalenes in good yields.

The activation of C–O bonds in allylic acetates in water as a suspension medium has been accelerated by carrying out the reactions in the presence of platinum complexes associated with ligands. The platinum-catalyzed allylation of aminonaphthalenes using allylic acetates gave the corresponding ...

Two kinds of 3-nitro-2-pyridyl glycosides were synthesized and evaluated as substrates for continuous spectrophotometric assay for glycosidases. The liberated aglycon, 2-hydroxy-3-nitropyridine, immediately tautomerized to 3-nitro-2(1H)-pyridone, causing an absorption shift of ca. 60 nm even und...

The optimized molecular structure and corresponding vibrational assignments of 3-hydroxy-6-methyl-2-nitropyridine have been investigated using density functional theory (DFT) B3LYP method with 6-311++G(d,p), 6-311++G(2d,2p) and 6-311++G(3d,3p) basis sets. Investigation of the relative orientatio...