@article { ISI:000313230200031, title = {Catalytic and DFT study of selective ethylene oligomerization by nickel(II) oxime-based complexes}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {366}, year = {2013}, month = {JAN}, pages = {238-246}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The reactivity of nickel(II) thiophenealdoxime complex (3) toward oligomerization of ethylene in the presence of an alkylaluminum co-catalyst has been studied. The complex was found to be a selective ethylene dimerization catalyst in the presence of co-catalysts such as methylalumoxane (MAO) and diethylaluminum chloride (DEAC). With DEAC, the productivity was considerably higher than with MAO. Under optimum conditions the productivity reaches 388 kg/mol catalyst/h/bar with DEAC whereas for MAO this value was 119 kg/mol catalyst/h/bar. Complex 3 displays good ethylene conversions of up to a maximum of 90\% with exceptionally high alpha-selectivity for 1-butene (\>99.5\%) amongst C-4 products. Computational studies using density functional theory (DFT) were also carried out to ascertain the decomposition pathway for 3 as well as that for Ni(II) complex of the pyridine ketoxime ligand 2. The results suggest that loss of one of the two bidentate oxime ligands attached to the metal center through reaction with DEAC is likely for both 2 and 3. Further, calculations indicate that the subsequent decomposition step was significantly more probable for 3 than for 2 thus explaining why the pyridine ketoxime ligand bound nickel complex 2 was experimentally found to be more stable than the thiophene aldoxime bound nickel complex 3. Calculations also show that the proton of the -OH group (oxime) plays a major role in the stability of the molecules. This was confirmed experimentally by synthesizing the Ni(II) dichloro complex of Pyridine-2-carbaldehyde O-methyloxime 5 and reacting it with ethylene under similar conditions. 5 was found to be highly active even at low co-catalyst concentrations. (c) 2012 Elsevier B.V. All rights reserved.

}, keywords = {Butene-1, Ethylene dimerization, Ni(II) complex, Thiophene aldoxime}, issn = {1381-1169}, doi = {10.1016/j.molcata.2012.09.029}, author = {Tayade, Kamlesh N. and Mane, Manoj V. and Sen, Suman and Murthy, C. N. and Tembe, Gopal L. and Pillai, S. Muthukumaru and Vanka, Kumar and Mukherjee, Soumen} } @article { ISI:000349943000006, title = {Computational study of metal free alcohol dehydrogenation employing frustrated lewis pairs}, journal = {Journal of Organic Chemistry}, volume = {80}, number = {4}, year = {2015}, month = {FEB}, pages = {2081-2091}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The catalysis of acceptorless alcohol dehydrogenation (AAD) is an important area of research. Transition metal-based systems are known to be effective catalysts for this reaction, but developing metal free catalytic systems would lead to highly desirable cheaper and greener alternatives. With this in mind, this computational study investigates design strategies than can lead to metal free frustrated Lewis pairs (FLPs) that can be employed for AAD catalysis. A careful study of 36 different proposed FLP candidates reveals that several new FLPs can be designed from existing, experimentally synthesized FLPs that can rival or be even better than state-of-the-art transition metal-based systems in catalyzing the alcohol dehydrogenation process.

}, issn = {0022-3263}, doi = {10.1021/jo5023052}, author = {Mane, Manoj V. and Rizvi, Masood A. and Vanka, Kumar} } @article {46952, title = {Catalyst-free regioselective [3+2] cycloadditions of alpha,beta-unsaturated N-arylnitrones with alkenes to access functionalized isoxazolidines: a DFT study}, journal = {Chemistry-An Asian Journal}, volume = {15}, year = {2020}, month = {MAR}, pages = {899-903}, type = {Article}, abstract = {

The catalyst-free regioselective [3+2]-cycloaddition of alpha,beta-unsaturated N-arylnitrones with alkenes are developed. The series of synthetically important functionalized isoxazolidines are prepared in good to excellent yields by step economic pathway under ligand and transition-metal-free conditions. The regioselective cycloaddition pathway supported by control experiment and computational study.

}, keywords = {DFT study, isoxazolidines, metal and ligand free, nitrone cycloaddition, Regioselective}, issn = {1861-4728}, doi = {10.1002/asia.201901754, Early Access Date = FEB 2020}, author = {Ghosh, Arnab and Mane, Manoj V. and Rode, Haridas B. and Patil, Siddappa A. and Sridhar, Balasubramanian and Dateer, Ramesh B.} }