@article { ISI:000253450900068, title = {Alkene epoxidation catalyzed by vanadomolybdophosphoric acids supported on hydrated titania}, journal = {Catalysis Communications}, volume = {9}, number = {5}, year = {2008}, month = {MAR}, pages = {931-938}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Vanadomolybdophosphoric acids wet-impregnated oil hydrated titania (TiO(2) - xH(2)O), make ail efficient catalytic system for the epoxidation of a variety of alkenes with organic solvent extracted TBHP as the oxidant. By,in appropriate choice of solvent, the catalyst call be reused at least three times without much loss in the activity for subsequent runs. XRD shows that the heteropoly acid is uniformly dispersed over the support and up to 15 wt\% loading of the heteropoly acid, no additional peak of the same call be seen in the XRD pattern of the catalyst. The reactivity varied with the nature of alkene but the major product was always the corresponding epoxide. The catalytic system is free of high temperature calcination steps and tedious multi-step procedures, normally encountered in the heter-ogenization of heteropoly acids. (c) 2007 Elsevier B.V. All rights reserved.

}, keywords = {alkenes, epoxidation, heteropoly acids, TBHP, titania, vanadomolybdophosphoric acids}, issn = {1566-7367}, doi = {10.1016/j.catcom.2007.09.022}, author = {Ingle, Rohit H. and Vinu, A. and Halligudi, Shivaraj B.} } @article { ISI:000260803700002, title = {Lacunary Keggin type polyoxotungstates in conjunction with a phase transfer catalyst: an effective catalyst system for epoxidation of alkenes with aqueous H2O2}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {294}, number = {1-2}, year = {2008}, month = {OCT}, pages = {8-13}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Na-9[SbW9O33] in conjunction with a phase transfer catalyst (methyl tricapryl ammonium chloride) is a highly efficient catalytic system for the selective epoxidation of alkenes with aqueous H2O2 as the oxidant. Importantly, the reactions can be carried out in the absence of any organic solvents. The alkene epoxidation reactions with both, a transition metal ion substituted polyoxotungstate as well as a transition metal ion free polyoxotungstate precursor indicates that the tungstate group is the active center for the oxidation reaction. It was also observed that the transition metal ion does not play any significant role in the reaction. IR studies support the formation of tungsten-peroxo species and also show that the catalyst is stable in the presence of phase transfer catalyst when aqueous H2O2 is used as an oxidant. (C) 2008 Elsevier B.V. All rights reserved.

}, keywords = {alkenes, Aqueous H2O2, epoxidation, Na-9[SbW9O33], Phase transfer catalyst, polyoxometalates}, issn = {1381-1169}, doi = {10.1016/j.molcata.2008.07.003}, author = {Ingle, Rohit H. and Raj, N. K. Kala} } @article { ISI:000284052600021, title = {Covalently immobilized triphenylphosphine rhodium complex: synthesis, characterization, and application in catalytic olefin hydrogenation}, journal = {Chemcatchem}, volume = {2}, number = {11}, year = {2010}, month = {NOV}, pages = {1477-1482}, publisher = {WILEY-BLACKWELL}, address = {COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA}, abstract = {

A trimethoxysilane functionalized triphenylphosphine was coordinated to rhodium(I) and the resulting rhodium complex was covalently bound to a mesoporous SBA-15 support. The catalytic activity of this hybrid material was studied for the hydrogenation of 2-cyclohexen-1-one and compared with the corresponding homogeneous catalyst. According to the (31)P-MAS NMR data, the catalytically active species was stable against oxidation; no structural change could be detected after exposing it to air for more than two months. Transmission electron microscopy (TEM) measurements on the used catalyst confirmed that the rhodium species was also stable against reduction to the metal because the formation of rhodium nanoparticles during the catalysis could be excluded. The kinetic curves of the recycled system confirmed that this hybrid catalyst shows excellent activity, selectivity, stability, and reusability, and is truly heterogeneous in the hydrogenation reaction.

}, keywords = {alkenes, heterogeneous catalysis, Hydrogenation, mesoporous materials, Rhodium}, issn = {1867-3880}, doi = {10.1002/cctc.201000133}, author = {Wang, Lei and Jia, Mingjun and Shylesh, Sankaranarayanapillai and Philippi, Thomas and Seifert, Andreas and Ernst, Stefan and Singh, Anand Pal and Thiel, Werner R.} } @article { ISI:000284533700013, title = {Regiospecific azidoiodination of alkenes with sodium periodate, potassium iodide, and sodium azide: a high-yield synthesis of beta-iodoazides}, journal = {Synthesis-Stuttgart}, number = {22}, year = {2010}, month = {NOV}, pages = {3879-3882}, publisher = {GEORG THIEME VERLAG KG}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

The combination of sodium periodate, potassium iodide, and sodium azide has been found to be an efficient, simple, and inexpensive reagent system for azidoiodination of alkenes. The regiospecific 1,2-azidoiodination proceeds in an anti-Markovnikov fashion to produce beta-iodoazides in excellent yields.

}, keywords = {alkenes, azides, azidoiodination, beta-iodoazides, regio-specific}, issn = {0039-7881}, doi = {10.1055/s-0030-1258250}, author = {Chouthaiwale, Pandurang V. and Karabal, Pratibha U. and Suryavanshi, Gurunath and Sudalai, Arumugam} } @article { ISI:000288848900007, title = {Enantiospecific route to (+)-(1R, 3S)-cis-chrysanthemic acid from (-)-D-pantolactone(1)}, journal = {Synthesis-Stuttgart}, number = {7}, year = {2011}, month = {APR}, pages = {1067-1070}, publisher = {GEORG THIEME VERLAG KG}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

In this paper, a novel route for the synthesis of (+)-(1R,3S)-cis-chrysanthemic acid is described. The use of readily available (-)-D-pantolactone as a starting point, application of ring-closing metathesis to form the cyclopentene intermediate, and Haller-Bauer/Grob-type fragmentation to form the target compound are the highlights of the present synthesis.

}, keywords = {alkenes, Metathesis, ring closure, stereoselective synthesis, Wittig reaction}, issn = {0039-7881}, doi = {10.1055/s-0030-1258451}, author = {Hajare, Atul K. and Datrange, Laxmikant S. and Murthy, Y. L. N. and Bhuniya, Debnath and Reddy, D. Srinivasa} } @article { ISI:000306766200040, title = {NaIO4-NaN3-mediated diazidation of styrenes, alkenes, benzylic alcohols, and aryl ketones}, journal = {Tetrahedron Letters}, volume = {53}, number = {32}, year = {2012}, month = {AUG}, pages = {4195-4198}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Sodium periodate and sodium azide combination has been found to be an excellent reagent system suitable for the direct diazidation of styrenes, alkenes, benzylic alcohols, and aryl ketones to produce the corresponding vicinal and geminal diazides respectively in high yields under mild reaction conditions. (C) 2012 Elsevier Ltd. All rights reserved.

}, keywords = {alkenes, Aryl ketones, Geminal diazides, Sodium periodate, Vicinal diazides}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2012.05.140}, author = {Kamble, Dayanand A. and Karabal, Pratibha U. and Chouthaiwale, Pandurang V. and Sudalai, Arumugam} } @article { ISI:000340872300007, title = {Clay-supported copper nitrate (Claycop): a mild reagent for the selective nitration of aromatic olefins}, journal = {Synlett}, volume = {25}, number = {14}, year = {2014}, month = {SEP}, pages = {1997-2000}, publisher = {GEORG THIEME VERLAG KG}, type = {Article}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

A straightforward and highly selective method has been developed for the nitration of a wide variety of aromatic and aliphatic olefins by using a clay-supported copper nitrate (Claycop) and a catalytic amount of (2,2,6,6-tetramethylpiperidin-1-yl)oxyl, an inexpensive and mild reagent system. High conversions and exclusive E-selectivity, together with the environmentally benign nature of the Claycop reagent, make this a green method and an attractive alternative to established methods.

}, keywords = {alkenes, nitrations}, issn = {0936-5214}, doi = {10.1055/s-0034-1378513}, author = {Begari, Eeshwaraiah and Singh, Chandani and Nookaraju, U. and Kumar, Pradeep} } @article {45975, title = {Palladium nanoparticles supported on magnesium hydroxide fluorides: a selective catalyst for olefin hydrogenation}, journal = {ChemCatChem}, volume = {6}, year = {2014}, month = {NOV}, pages = {3182-3191}, type = {Article}, abstract = {

A one-pot synthesis of palladium nanoparticles supported on magnesium hydroxide fluoride has been performed with the fluorolytic sol-gel method. The prepared catalysts were characterized by using various physicochemical techniques. The sol-gel method led to high surface area (\>135 m(2)g(-1)), mesoporous catalysts (pore volume=0.19-0.23 cm(3)g(-1), pore diameter=3-5 nm) with uniformly dispersed palladium nanoparticles approximately 2 nm in diameter on the surface. The catalysts synthesized by using different concentrations of aqueous hydrofluoric acid exhibited changing surface and acidic properties. Very high dispersion of palladium on magnesium fluoride (47\%) was obtained with 1 wt\% palladium loading. The catalysts were used for hydrogenation of various olefins in the presence of other organic functionalities at room temperature and atmospheric hydrogen pressure. Various substituted olefins were hydrogenated with almost 100\% conversion and selectivity. The catalysts were recycled efficiently over five cycles without appreciable loss in catalytic activity. There was no palladium leaching under the reaction conditions, which was confirmed by inductively coupled plasma atomic emission spectroscopy analysis. Activation of olefin on the catalyst surface could not be observed by in situ FTIR studies, indicating facile activation of hydrogen on the palladium supported on magnesium hydroxide fluoride.

}, keywords = {alkenes, heterogeneous catalysis, Hydrogenation, magnesium fluorides, Palladium}, issn = {1867-3880}, doi = {10.1002/cctc.201402469}, author = {Acham, Vaibhav R. and Biradar, Ankush V. and Dongare, Mohan K. and Kemnitz, Erhard and Umbarkar, Shubhangi B.} } @article { ISI:000364330600008, title = {Highly regioselective isomerizing hydroformylation of long-chain internal olefins catalyzed by a rhodium bis(phosphite) complex}, journal = {ChemCatChem}, volume = {7}, number = {21}, year = {2015}, month = {NOV}, pages = {3468-3471}, publisher = {WILEY-V C H VERLAG GMBH}, address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY}, abstract = {

The single-step synthesis, coordination behavior, and application of a bis(phosphite) ligand in the isomerizing hydroformylation of internal olefins was investigated. Interestingly, high-pressure NMR spectroscopy investigations revealed unexpected inequivalency of the two phosphorus nuclei, which display bisequatorial coordination of the bis(phosphite) ligand in a trigonal bipyramidal rhodium complex. Upon employment in the isomerizing hydroformylation of the exceedingly challenging plant oil derived substrate methyl oleate, the bis(phosphite) rhodium complex revealed an unprecedented linear selectivity of 75\%.

}, keywords = {alkenes, bis(phosphite)s, Hydroformylation, isomerization, Rhodium}, issn = {1867-3880}, doi = {10.1002/cctc.201500743}, author = {Pandey, Swechchha and Chikkali, Samir H.} } @article {47805, title = {Hydroformylation of olefins by metals other than rhodium}, journal = {Journal of Organometallic Chemistry}, volume = {960}, year = {2022}, month = {FEB}, pages = {122231}, type = {Article}, abstract = {Metal catalyzed hydroformylation of alkenes is an atom economic transformation to construct useful aldehydes and is being industrially practiced for decades. The most commonly used metal for this transformation on an industrial scale is rhodium. However, rhodium is rare, costly, and is depleting at a skyrocketing rate. Therefore, finding a suitable alternative to rhodium for metal-catalyzed hydroformylation has been on the radar of many academic and industrial researchers. This review presents the scientific advancements reported in the hydroformylation reaction using metals other than rhodium. An overview of recent progress in palladium, iridium, ruthenium, cobalt, platinum, and iron-catalyzed hydroformylation is presented. Hydroformylation of alkenes and alkynes, using syngas as well as syngas surrogates is examined. The evaluation of the current status of non-rhodium metals in hydroformylation suggests that the field is still in a nascent stage and, except cobalt, no other metal poses a significant challenge to the dominance of rhodium. Deep mechanistic understanding of rate-limiting elementary steps in the non-rhodium metals is largely missing and thus only limited success is reported. Intense research on ligand design, mechanistic understanding, and choice of non-rhodium metal precursors may change this scenario in near future.}, keywords = {aldehydes, alkenes, catalysis, Hydroformylation, Non-rhodium metals}, issn = {0022-328X}, doi = {10.1016/j.jorganchem.2021.122231}, author = {Kumar, Rohit and Chikkali, Samir H.} } @article {48311, title = {Iron-catalyzed magnesium-mediated formal hydroformylation of alkynes and alkenes}, journal = {ChemCatChem}, volume = {15}, year = {2023}, month = {FEB }, type = {Article}, abstract = {

Alkynes and alkenes are routinely converted to corresponding synthetically versatile aldehydes using rhodium-catalyzed hydroformylation. However, rhodium is rare, precious, costly, and depleting at a considerably high rate. Reported here is iron-catalyzed, magnesium-mediated, formal hydroformylation of alkynes and alkenes in the absence of syngas. Readily available FeCl2 in the presence of alkyl magnesium halide, and dimethyl formamide, catalyzes hydroformylation of various alkynes and selectively produces alpha,beta-unsaturated aldehydes in good to excellent conversion. Mechanistic investigations revealed the presence of vinyl magnesium intermediate, the kinetic study disclosed the first-order dependence of the reaction on iron loading, and the control experiment authenticated the iron catalyst{\textquoteright}s homogeneous nature. The scope of this methodology was amplified, and 20 alkenes were examined. [Fe(acac)(3)] in the presence of ligand, alkyl magnesium halide, and dimethyl formamide catalyzed the hydroformylation of alkenes and displayed good to excellent conversion. An earth-abundant iron catalyst offering a syngas cylinder-free safe alternative to high-pressure hydroformylation has been reported.

}, keywords = {aldehydes, alkenes, Alkynes, Hydroformylation, iron catalysis}, issn = {1867-3880}, doi = {10.1002/cctc.202201394}, author = {Tewari, Tanuja and Kumar, Rohit and Chikkali, Samir H.} }