@article { ISI:000238502400002, title = {Effect of calcination temperature on the catalytic activity of zirconia-supported heteropoly acids}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {253}, number = {1-2}, year = {2006}, month = {JUL}, pages = {8-15}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Zirconia-supported silicotungstic acid (15\% STA) catalyst with different calcination temperatures (600-850 degrees C) was prepared by suspending zirconium oxyhydroxide in methanol solution of STA followed by drying and calcination. These catalysts were characterized by XRD, FTIR pyridine adsorption and DRUV-vis spectroscopy. The catalysts showed both Bronsted as well as Lewis acidity and 15\% STA on zirconia calcined at 750 degrees C (15 SZ-750) had the highest Bronsted acidity. Characterization of 15 SZ-750 catalyst by Raman spectroscopy showed the presence of zirconia-anchored mono-oxotungstate as the major tungsten species present in this catalyst. These catalysts were used in benzoylation of veratrole with benzoic anhydride and 15 SZ-750 catalyst showed the highest activity. For catalyst with support calcined at different temperatures before HPA impregnation, catalytic activity decreases as the support calcination temperature increases due to the decrease in Bronsted acidity. Comparison of the catalytic activity of 15 SZ-750 with that of zirconia-supported phosphotungstic acid (15\%, calcined at 750 degrees C, 15 PZ-750) in benzoylation of veratrole with benzoic anhydride, acylation of anisole with acetic anhydride and in alkylation of diphenylether with 1-dodecene showed that 15 SZ-750 catalyst has higher activity and deactivation resistance due to its higher Bronsted acidity. The deactivated catalyst could be regenerated by calcination without appreciable loss in activity. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {Acylation, Alkylation, Anisole, diphenylether, Phosphotungstic acid, Silicotungstic acid, veratrole, Zirconia}, issn = {1381-1169}, doi = {10.1016/j.molcata.2006.02.068}, author = {Devassy, Biju M. and Halligudi, Shivaraj B.} } @article { ISI:000243831600015, title = {Acylation of anisole with long-chain carboxylic acids over wide pore zeolites}, journal = {Applied Catalysis A-General}, volume = {317}, number = {2}, year = {2007}, month = {FEB}, pages = {250-257}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The acylation of anisole with long-chain carboxylic acids (hexanoic, octanoic and decanoic) has been studied over three large pore zeolites-beta (BEA), faujasite (FAU) and mordenite (MOR). The acylation of anisole with the long chain acids produced mainly the ketone (4-methoxy phenyl alkyl ketone) and small amounts of the ester (phenyl alkanoate). The results revealed the reaction to be influenced by the type of zeolite and its Si/Al ratio (acidity) besides the chain length (carbon number) of the carboxylic acid. In the acylation of anisole with hexanoic acid, the activity of the zeolites increased with dealumination as it led to the generation of mesopores that resulted in a decrease in diffusion resistance of the zeolites. The reactivity of the acids in the acylation reaction was found to decrease with increase in the carbon number. The experimental data have been fitted into a pseudo first order kinetic model. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {Acylation, Anisole, decanoic acid, hexanoic acid, octanoic acid, zeolites}, issn = {0926-860X}, doi = {10.1016/j.apcata.2006.10.023}, author = {Wagholikar, S. G. and Niphadkar, P. S. and Mayadevi, S. and Sivasanker, S.} } @article { ISI:000257016800018, title = {Titania supported silicotungstic acid: an efficient solid acid catalyst for veratrole acylation}, journal = {Catalysis Communications}, volume = {9}, number = {10}, year = {2008}, month = {JUN}, pages = {2026-2029}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Titania supported silicotungstic acid (STA) with different STA loading (10-25 wt\%) and calcination temperature (650-750 degrees C) were prepared by wet impregnation method. The catalysts have been represented by a general formula xSTiO(2)y (where x denotes wt\%, S denotes STA and y denotes calcination temperature in degrees C). These catalysts were characterized by techniques such as X-ray diffraction, surface analysis, FTIR-pyridine and TPD-NH(3) and were used as heterogeneous solid acid catalysts in the liquid phase acylation of veratrole with acetic anhydride (Ac(2)O). It was found that 20STiO(2)700 gave the highest activity in acylation reaction due to its highest acidity. (C) 2008 Elsevier B.V. All rights reserved.

}, keywords = {acetic anhydride, Acylation, Silicotungstic acid, titania, veratrole}, issn = {1566-7367}, doi = {10.1016/j.catcom.2008.03.043}, author = {Waghmare, Nilesh G. and Kasinathan, Palraj and Amrute, Amol P. and Lucas, Nishita and Halligudi, Shivaraj B.} } @article { ISI:000263158700050, title = {Acylation of nitrobenzene and substituted nitrobenzenes by benzoyl chloride using GaClx- and GaAlClx-grafted meporous Si-MCM-41 catalysts}, journal = {Microporous and Mesoporous Materials}, volume = {119}, number = {1-3}, year = {2009}, month = {MAR}, pages = {360-362}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A acylation of nitrobenzene and substituted nitrobenzene by benzoyl chloride can be accomplished with good yield in a short reaction period (\<= 3 h), even in the presence of moisture, using GaClx- and GaAlClx-grafted mesoporous silica (Si-MCM-41) catalyst. The catalyst is reusable/environmentally friendly. The presence of moisture in the catalyst has beneficial effect on the acylation reaction. (C) 2008 Elsevier Inc. All rights reserved.

}, keywords = {Acylation, Benzoyl chloride, GaAlClx-grafted Si-MCM-41, GaClx-grafted Si-MCM-41, nitrobenzene}, issn = {1387-1811}, doi = {10.1016/j.micromeso.2008.11.001}, author = {Choudhary, Vasant R. and Jha, Rani} } @article { ISI:000262301900031, title = {Enhancing intermolecular benzoyl-transfer reactivity in crystals by growing a {\textquoteleft}{\textquoteleft}reactive{\textquoteright}{\textquoteright} metastable polymorph by using a chiral additive}, journal = {Chemistry-A European Journal}, volume = {15}, number = {1}, year = {2009}, month = {NOV}, pages = {261-269}, publisher = {WILEY-V C H VERLAG GMBH}, address = {PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY}, abstract = {

Racemic 2,4-di-O-benzoyl-myo-inositol-1,3,5-orthoacetate, which normally crystallizes in a monoclinic form (form I, space group P2(1)/n) could be persuaded to crystallize out as a metastable polymorph (form II, space group C2/c) by using a small amount of either D- or L- 2,4-di-O-benzoyl-myo-inositol-1,3,5-orthoformate as an additive in the crystallization medium. The structurally similar enantiomeric additive was chosen by the scrutiny of previous experimental results on the crystallization of racemic 2,4-di-O-benzoyl-myo-inositol-1,3,5-orthoacetate. Form II crystals call be thermally transformed to form I crystals at about 145 degrees C. The relative organization of the molecules in these dimorphs vary slightly in terms of the helical assembly of molecules, that is, electrophile (El)center dot center dot center dot nucleophile (Nu) and C-H center dot center dot center dot pi interactions, but these minor variations have a profound effect on the facility and specificity of benzoyl-group-transfer reactivity in the two crystal forms. While form II crystals undergo a clean intermolecular benzoyl-group-transfer reaction, form I crystals are less reactive and undergo non-specific benzoyl-group transfer leading to a Mixture of products. The role played by the additive in fine-tuning small changes that are required in the molecular packing opens up the possibility of creating new polymorphs that show varied physical and chemical properties. Crystals of D-2.6-di-O-benzoyl-myo-inositol-1,3,5-orthoformate (additive) did not show facile benzoyl-group-transfer reactivity (in contrast to the corresponding racemic compound) due to the lack of proper juxtaposition and assembly of molecules.

}, keywords = {Acylation, carbohydrates, Crystal growth, cyclitols, solid-state reactions}, issn = {0947-6539}, doi = {10.1002/chem.200801484}, author = {Murali, Chebrolu and Shashidhar, Mysore S. and Gonnade, Rajesh G. and Bhadbhade, Mohan M.} } @article { ISI:000264206200011, title = {Regioselective O-acylation of myo-inositol 1,3,5-orthoesters: dependence of regioselectivity on the stoichiometry of the base}, journal = {Tetrahedron}, volume = {65}, number = {13}, year = {2009}, month = {MAR}, pages = {2703-2710}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A metal mediated unusual 1-3 acyl migration from C4-O to C2-OH of myo-inositol 1,3,5-orthoformate was observed during the alkylation of racemic 4-O-benzoyl-myo-inositol 1,3,5-orthoformate. This has been exploited for the selective esterification of either the C4(6)-OH or the C2-OH of myo-inositol by varying the amount of the base used. While the use of 1 equiv of the base (sodium hydride or potassium tert-butoxide) for the acylation of myo-inositol orthoesters gives the corresponding C4-ester exclusively, the use of two or more equivalents of base for the same reaction gives the C2-ester exclusively. The relatively higher stability of the alkoxide of racemic 2-O-acyl-myo-inositol 1,3,5-orthoester as compared to the alkoxide of 4-O-acyl-myo-inositol 1,3,5-orthoester is suggested to be responsible for the observed isomerization. (c) 2009 Elsevier Ltd. All rights reserved.

}, keywords = {Acylation, Cyclitol, Inositol, Orthoester, Regioselectivity, transesterification}, issn = {0040-4020}, doi = {10.1016/j.tet.2009.01.060}, author = {Sureshan, Kana M. and Devaraj, Subramanian and Shashidhar, Mysore S.} } @article { ISI:000274058400003, title = {Nature of the acid sites in the metal triflates immobilized in SBA-15 and their role in the friedel-crafts acylation of naphthalene}, journal = {Applied Catalysis A-General}, volume = {372}, number = {2}, year = {2010}, month = {JAN}, pages = {130-137}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The Zn-triflate molecules loaded (5-30 mol\%) in mesoporous SBA-15 silicate exhibited considerably higher catalytic activity for liquid-phase Friedel-Crafts (FC) acylation of naphthalene with p-toluoyl chloride, as compared to the corresponding triflates of La, Ce and Y. In situ FTIR studies revealed that the triflate molecules occluded in the channels of SBA-15 may cause severe perturbation of surface hydroxyl groups, without undergoing an electronic binding. The metal cations of the triflate molecules, on the other hand, participated in direct bonding of the reactant molecules and also helped in the formation of some Bronsted type surface acid sites. This article discusses the role of the acid sites generated on occlusion of metal triflates in SBA-15, as monitored by using NH(3)-TPD and pyridine-IR spectroscopy, in the Friedel-Crafts acylation of naphthalene. (C) 2009 Elsevier B.V. All rights reserved.

}, keywords = {Acylation, Mesoporous silica, Metal triflate, Naphthalene}, issn = {0926-860X}, doi = {10.1016/j.apcata.2009.10.021}, author = {Selvakumar, S. and Gupta, Narendra M. and Singh, A. P.} } @article { ISI:000324316300042, title = {Identification of molecular crystals capable of undergoing an acyl-transfer reaction based on intermolecular interactions in the crystal lattice}, journal = {Chemistry-A European Journal}, volume = {19}, number = {38}, year = {2013}, month = {SEP}, pages = {12867-12874}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

Investigation of the intermolecular acyl-transfer reactivity in molecular crystals of myo-inositol orthoester derivatives and its correlation with crystal structures enabled us to identify the essential parameters to support efficient acyl-transfer reactions in crystals: 1)the favorable geometry of the nucleophile (OH) and the electrophile (CO) and 2)the molecular assembly, reinforced by CH interactions, which supports a domino-type reaction in crystals. These parameters were used to identify another reactive crystal through a data-mining study of the Cambridge Structural Database. A 2:1 co-crystal of 2,3-naphthalene diol and its di-p-methylbenzoate was selected as a potentially reactive crystal and its reactivity was tested by heating the co-crystals in the presence of solid sodium carbonate. A facile intermolecular p-toluoyl group transfer was observed as predicted. The successful identification of reactive crystals opens up a new method for the detection of molecular crystals capable of exhibiting acyl-transfer reactivity.

}, keywords = {Acylation, domino reactions, intermolecular interactions, solid-state reactions, X-ray diffraction}, issn = {0947-6539}, doi = {10.1002/chem.201301058}, author = {Tamboli, Majid I. and Krishnaswamy, Shobhana and Gonnade, Rajesh G. and Shashidhar, Mysore S.} } @article { ISI:000321490900014, title = {Synthesis of a sex pheromone of the longtailed mealybug, pseudococcus longispinus}, journal = {Synthesis-Stuttgart}, volume = {45}, number = {12}, year = {2013}, month = {JUN}, pages = {1689-1692}, publisher = {GEORG THIEME VERLAG KG}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

The synthesis of a recently identified and highly active sex pheromone of the longtailed mealybug, Pseudococcus longispinus is reported. A concise synthetic route, use of the under explored Meyer-Schuster rearrangement, Claisen rearrangement, and ring-closing metathesis are the highlights of this work.

}, keywords = {Acylation, Metathesis, pheromones, rearrangement, Total synthesis}, issn = {0039-7881}, doi = {10.1055/s-0033-1338450}, author = {Kurhade, Suresh E. and Siddaiah, V. and Bhuniya, Debnath and Reddy, D. Srinivasa} } @article { ISI:000344439400007, title = {Regioselective acylation of 2-methoxy naphthalene catalyzed by supported 12-phosphotungstic acid}, journal = {Applied Catalysis A-General}, volume = {486}, year = {2014}, month = {SEP}, pages = {55-61}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

12-Phosphotungstic acid supported on silica gel, zirconium sulfate, and a combination of silica gel and zirconium sulfate (50\% w/w) were employed as solid acid catalysts for regioselective acylation of 2-methoxynaphtalene with acetic anhydride. 1-(6-Methoxynaphthalen-2-yl)ethanone (2,6-AMN), a commercially important intermediate for production of Naproxen, was obtained with excellent selectivity (\>98\%) at 67-68\% conversion using 12-phosphotungstic acid supported on silica gel 20\% (w/w) in refluxing tetrachloroethane. The unreacted starting material can be easily separated from the product by a simple crystallization from nonane. (C) 2014 Elsevier B.V. All rights reserved.

}, keywords = {Acylation, Naproxen, Phosphotungstic acid, Silica gel, Supported, Zirconium sulfate}, issn = {0926-860X}, doi = {10.1016/j.apcata.2014.08.026}, author = {Kumaraguru, Thenkrishnan and Devi, Ayala Vedamayee and Siddaiah, Vidavalur and Rajdeo, Kishor and Fadnavis, Nitin W.} } @article {44556, title = {Regioselective and efficient enzymatic synthesis of antimicrobial andrographolide derivatives}, journal = {Bioorganic \& Medicinal Chemistry Letters}, volume = {28}, year = {2018}, month = {APR }, pages = {1132-1137}, abstract = {

Labdane diterpene andrographolide (1) is a major constituent of Andrographis paniculata and known to exhibit wide spectrum of biological activities. In this study, regioselective monoesters of (1) have been synthesized by using Amano lipase AK (Pseudomonas fluorescens) as a biocatalyst. Amano lipase AK was able to execute highly efficient esterification of hydroxyl group attached to C-14 carbon of (1) in presence of acyl donors. Among the various synthesized derivatives including two novel compounds such as andrographolide-14-propionate (3) and andrographolide-14-caproate (5) displayed antimicrobial activity against Staphylococcus aureus with low minimal inhibitory concentration (MIC) 4 mu g/mL and 16 mu g/mL respectively. Furthermore, they have shown low hemolysis activity at their respective MIC and increase in the permeability of the bacterial cell membrane as delineated by FITC uptake and SEM imaging studies. (C) 2018 Elsevier Ltd. All rights reserved.

}, keywords = {Acylation, Andrographolide, Antimicrobial activity, biocatalysis, Hemolysis, Lipase, Natural product}, issn = {0960-894X}, doi = {10.1016/j.bmcl.2018.01.007}, author = {Patil, Harshal S. and Jadhav, Dipesh D. and Paul, Ajay and Mulani, Fayaj A. and Karegaonkar, Shrikant J. and Thulasiram, Hirekodathakallu V.} } @article {47496, title = {Efficient and cost effective synthesis of acetamides catalyzed by calcium chloride}, journal = {Indian Journal of Chemistry Section B-Organic Chemistry Including Medicinal Chemistry}, volume = {58}, year = {2019}, month = {OCT}, pages = {1125-1130}, type = {Article}, abstract = {CaCl2 has been found to be an efficient and cost effective catalyst for the rapid synthesis of acetamides in high yields. The use of stoichiometric quantities of acetic anhydride under solvent free conditions without any additional chromatographic purifications makes this protocol a safe alternative to the existing methods.}, keywords = {Acetamide, acetylation, Acylation, Amine, CaCl2}, issn = {0376-4699}, author = {Sangole, M. T. and Thorat, S. M. and Shirsath, S. and Deshmukh, S. P. and Muthukrishnan, M. and Mujahid, M.} } @article {47631, title = {Construction of two-component chemically reactive supramolecular assemblies-acyl migration reactions in cocrystals of napthalene-2,3-diol and its diesters}, journal = {ChemPlusChem}, volume = {86}, year = {2021}, month = {AUG}, pages = {1128-1134}, type = {Article}, abstract = {Reactions in solids are of contemporary interest due to applications in pharmaceutical industries to environmental sustainability. Although several reactive crystals that support chemical reactions have been identified and characterized, the same cannot be said about reactive cocrystals. Earlier we correlated the facile acyl group transfer reactions in crystals with supramolecular parameters obtained from the crystal structures. The structure-reactivity correlation revealed the requirement of proper juxtaposition of electrophile (C=O) and the nucleophile (OH) with distance (similar to 3.2 angstrom) and angle (similar to 90 degrees) along the chain structure. The current article describes the preparation of cocrystals that are capable of supporting intermolecular acyl group transfer reactions in a group of structurally similar molecules. The cocrystals of naphthalene 2,3-diol and its corresponding diesters showed a facile solid state acyl transfer reaction, which has been well correlated with their crystal structures.}, keywords = {Acylation, domino reactions, intermolecular interactions, reaction in cocrystal, solid-state reactions, X-ray diffraction}, issn = {2192-6506}, doi = {10.1002/cplu.202100139}, author = {Bahadur, Vir and Gonnade, Rajesh G. and Tamboli, I. Majid and Krishnaswamy, Shobhana and Shashidhar, Mysore S.} }