02641nas a2200241 4500008004100000022001400041245014300055210006900198260007700267300001200344490000700356520171700363653001402080653001802094653001902112653001402131653002602145100002102171700002702192700002402219700002502243856013102268 2009 eng d a0947-653900aEnhancing intermolecular benzoyl-transfer reactivity in crystals by growing a ``reactive'' metastable polymorph by using a chiral additive0 aEnhancing intermolecular benzoyltransfer reactivity in crystals  aPO BOX 10 11 61, D-69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcNOV a261-2690 v153 a

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.

10aAcylation10acarbohydrates10aCrystal growth10acyclitols10asolid-state reactions1 aMurali, Chebrolu1 aShashidhar, Mysore, S.1 aGonnade, Rajesh, G.1 aBhadbhade, Mohan, M. uhttps://library.ncl.res.in/content/enhancing-intermolecular-benzoyl-transfer-reactivity-crystals-growing-reactive-metastable-001817nas a2200241 4500008004100000022001400041245013000055210006900185260010600254300001400360490000700374520089400381653001401275653001301289653001301302653001501315653002101330653002401351100002301375700002501398700002701423856012501450 2009 eng d a0040-402000aRegioselective O-acylation of myo-inositol 1,3,5-orthoesters: dependence of regioselectivity on the stoichiometry of the base0 aRegioselective Oacylation of myoinositol 135orthoesters dependen aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcMAR a2703-27100 v653 a

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.

10aAcylation10aCyclitol10aInositol10aOrthoester10aRegioselectivity10atransesterification1 aSureshan, Kana, M.1 aDevaraj, Subramanian1 aShashidhar, Mysore, S. uhttps://library.ncl.res.in/content/regioselective-o-acylation-myo-inositol-135-orthoesters-dependence-regioselectivity-002007nas a2200241 4500008004100000022001400041245014900055210006900204260007700273300001600350490000700366520105300373653001401426653002101440653003201461653002601493653002201519100002301541700002701564700002401591700002701615856012301642 2013 eng d a0947-653900aIdentification of molecular crystals capable of undergoing an acyl-transfer reaction based on intermolecular interactions in the crystal lattice0 aIdentification of molecular crystals capable of undergoing an ac aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcSEP a12867-128740 v193 a

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.

10aAcylation10adomino reactions10aintermolecular interactions10asolid-state reactions10aX-ray diffraction1 aTamboli, Majid, I.1 aKrishnaswamy, Shobhana1 aGonnade, Rajesh, G.1 aShashidhar, Mysore, S. uhttps://library.ncl.res.in/content/identification-molecular-crystals-capable-undergoing-acyl-transfer-reaction-based-001997nas a2200265 4500008004100000022001400041245015900055210006900214260000800283300001400291490000700305520103700312653001401349653002101363653003201384653002601416653002601442653002201468100001701490700002401507700001901531700002701550700002701577856012701604 2021 eng d a2192-650600aConstruction of two-component chemically reactive supramolecular assemblies-acyl migration reactions in cocrystals of napthalene-2,3-diol and its diesters0 aConstruction of twocomponent chemically reactive supramolecular  cAUG a1128-11340 v863 aReactions 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.10aAcylation10adomino reactions10aintermolecular interactions10areaction in cocrystal10asolid-state reactions10aX-ray diffraction1 aBahadur, Vir1 aGonnade, Rajesh, G.1 aTamboli, Majid1 aKrishnaswamy, Shobhana1 aShashidhar, Mysore, S. uhttps://library.ncl.res.in/content/construction-two-component-chemically-reactive-supramolecular-assemblies-acyl-migration