Golam Rasul

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Isomeric 1- and 3-isoquinolinols (11 and 12) when activated in CF(3)SO(3)H-SbF(5) acid system undergo selective ionic hydrogenation with cyclohexane to give 5,6,7,8-tetrahydro-1(2H)- and 5,6,7,8-tetrahydro-3(2H)-isoquinolinones (22 and 27). Under the influence of aluminum chloride similar products were also obtained along with 3,4-dihydro-1(2H)- and(More)
A series of silylated carboxonium ions, 2a-6a, were prepared as long-lived species by treating triethylsilane and triphenylmethyl tetrakis(pentafluorophenyl)borate (Ph3C(+)B(C6F5)4-) with ketones, enones, carbonates, amides, and urea in CD2Cl2 solution. They were characterized by 13C and 29Si NMR spectroscopy at -78 degrees C. The NMR study indicates that(More)
Structures of the tert-pentyl cation (C(5)H(11)(+)) and its protonated dication (C(5)H(12)(2+), isopentane dication) were studied using ab initio methods at the MP2/cc-pVTZ level. Both C-C and C-H hyperconjugatively stabilized structures 1 and 2 , respectively, were found to be minima on the potential energy surface (PES) of the tert-pentyl cation.(More)
The mechanism of electrophilic aromatic nitration was revisited. Based on the available experimental data and new high-level quantum chemical calculations, a modification of the previous reaction mechanism is proposed involving three separate intermediates on the potential energy diagram of the reaction. The first, originally considered an unoriented(More)
Breeding for preharvest sprouting (PHS) resistance is of great interest in wheat-growing areas where high rainfall occurs during grain ripening and harvest. We have characterized 32 wheat accessions using 33 microsatellite markers flanking PHS quantitative trait loci (QTLs) previously identified on group 3, 4, 5, and 6 chromosomes of hexaploid wheat. A(More)
Aromatic carboxylic acids are obtained in good to excellent yield essentially free of diaryl ketones by carboxylation of aromatics with a carbon dioxide-Al(2)Cl(6)/Al system at moderate temperatures (20-80 degrees C). To optimize reaction conditions and study the reaction mechanism, experimental variables including temperature, amount of Al(2)Cl(6)/Al,(More)
The structures and energies of N(6)(2+) and N(4)(2+) were calculated by using the density functional theory method at the B3LYP/cc-aug-pVTZ level. The C(2)(h)() symmetric form 1 and D(infinity)(h) form 5 were found to be the stable minima for N(6)(2+) and N(4)(2+), respectively. Dissociation of 1 into 5 and N(2) was computed to be endothermic by 25.1(More)
Organofluorine compounds are becoming increasingly important in different fields, such as material science, agro chemistry, and the pharmaceutical industry. Nucleophilic trifluoromethylation is one of the widely used methods to incorporate a trifluoromethyl moiety into organic molecules. We have carried out extensive studies to develop varieties of easily(More)
Structures of superelectrophilic protonated propenoyl (H2C=CH-COH2+) and isopentenoyl ((CH3)2C=CH-COH2+) dications and their parent cations were calculated using ab initio methods at the MP2/6-311+G and MP2/cc-pVTZ levels. Energies were calculated using Gaussian-2 (G2) theory. The alpha-carbon (Calpha) protonated 3 and 7 were found to be the global minima(More)
The structures and stability of AlH(2+)n (n = 1-7 )dications were calculated at the ab initio MP2/aug-cc-pVTZ level of theory. The dications AlH(2+) 1 and AIH(2+2) 2 were characterized to be unstable thermodynamically. However, these and the stable dications, AlH(2+)n (n = 3-7) 3-7 have considerable kinetic barriers for deprotonation. Each of the structures(More)