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<p>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.</p>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-001812nas a2200349   4500008004100000022001400041245014800055210006900203260007700272300001600349490000700365520060800372653001600980653002200996653001501018653001901033653002201052100001701074700002101091700001501112700002401127700002401151700002101175700002201196700002101218700002701239700002201266700002201288700001901310700001601329856011701345       2014                        eng d  a0947-653900aHighly efficient chiral resolution of DL-arginine by cocrystal formation followed by recrystallization under preferential-enrichment conditions0 aHighly efficient chiral resolution of DLarginine by cocrystal fo  aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcAUG  a10343-103500 v203 a<p>An excellent chiral symmetry-breaking spontaneous enantiomeric resolution phenomenon, denoted preferential enrichment, was observed on recrystallization of the 1:1 cocrystal of dl-arginine and fumaric acid, which is classified as a racemic compound crystal with a high eutectic ee value (&gt;95%), under non-equilibrium crystallization conditions. On the basis of temperature-controlled video microscopy and in situ time-resolved solid-state (CNMR)-C-13 spectroscopic studies on the crystallization process, a new mechanism of phase transition that can induce preferential enrichment is proposed.</p>10aAmino acids10achiral resolution10acocrystals10aCrystal growth10aphase transitions1 aIwama, Sekai1 aKuyama, Kazunori1 aMori, Yuko1 aManoj, Kochunnoonny1 aGonnade, Rajesh, G.1 aSuzuki, Katsuaki1 aHughes, Colan, E.1 aWilliams, Andrew1 aHarris, Kenneth, D. M.1 aVeesler, Stephane1 aTakahashi, Hiroki1 aTsue, Hirohito1 aTamura, Rui  uhttps://library.ncl.res.in/content/highly-efficient-chiral-resolution-dl-arginine-cocrystal-formation-followed-0