01125nas a2200169 4500008004100000245011800041210006900159260000800228300001400236490000700250520032700257653017500584100002400759700002100783700002400804856012700828 2007 eng d00aSteric control in pd-mediated cycloisomerization of sugar alkynols: documentation of a rare allylic epimerization0 aSteric control in pdmediated cycloisomerization of sugar alkynol cJUL a4771-47740 v483 a

Pd-mediated cycloisomerization of C3-alkynylated glucofuranosyl derivatives revealed a dominance of steric factors over electronic factors. However, the intermediate glycals were epimerized prior to the ketalization and afforded the more stable cis-fused bicyclic ketals. (c) 2007 Elsevier Ltd. All rights reserved.

10aBis-Homopropargylic Alcohols; Oriented Organic-Synthesis;Nucleophilic-Attack; Room-Temperature; Palladium; Chemistry; Heterocycles;Complexes; Transformations; Sonogashira1 aRamana, Chepuri, V.1 aPatel, Pitarnbar1 aGonnade, Rajesh, G. uhttps://library.ncl.res.in/content/steric-control-pd-mediated-cycloisomerization-sugar-alkynols-documentation-rare-allylic01950nas a2200265 4500008004100000022001400041245012600055210006900181260007700250300001600327490000700343520093400350653002701284653001601311653003601327653001301363653002501376100002201401700002401423700002601447700002201473700003501495700002401530856013001554 2011 eng d a0947-653900aSynthesis and structural characterization of homochiral homo-oligomers of parent CIS- and trans-furanoid-beta-amino acids0 aSynthesis and structural characterization of homochiral homoolig aPO BOX 10 11 61, D-69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcNOV a12946-129540 v173 a

The synthesis of homochiral homo-oligomers of cis- and trans-3-aminotetrahydrofuran-2-carboxylic acids (parent cis- and trans-furanoid-beta-amino acids, referred to as ``cis-/trans-FAA'') has been carried out to understand their secondary structures and their dependence on the ring heteroatom. The oligomers of two diastereomers have been shown to have a distinct left-handed helicity. The cis-FAA homo-oligomers show a 14-helix structure, in contrast to the homo-oligomers of cis-ACPC, which adopt a sheet like structure. The trans-FAA homo-oligomers were found to adopt a 12-helix structure, the same trend found in trans-ACPC homo-oligomers. With the help of ab initio calculations, the structural features of cis-ACPC and cis-FAA hexamers were compared. We believe that the more compact packing of the cis-FAA hexapeptide should be due to a more favorable interaction between the ring and the backbone amide hydrogen.

10aab initio calculations10aAmino acids10aDensity functional calculations10aPeptides10asecondary structures1 aPandey, Sunil, K.1 aJogdand, Ganesh, F.1 aOliveira, Joao, C. A.1 aMata, Ricardo, A.1 aRajamohanan, Pattuparambil, R.1 aRamana, Chepuri, V. uhttps://library.ncl.res.in/content/synthesis-and-structural-characterization-homochiral-homo-oligomers-parent-cis-and-trans-001362nas a2200229 4500008004100000022001400041245014900055210006900204260007700273300001400350520043900364653001600803653002300819653002400842653001300866100002100879700002400900700003500924700002200959700002400981856012701005 2012 eng d a1434-193X00aSynthesis and structural characterization of homochiral homo-oligomers of cis-gamma-methoxy-substituted cis- and trans-furanoid-beta-amino acids0 aSynthesis and structural characterization of homochiral homoolig aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcMAY a2656-26633 a

Herein we describe the synthesis of cis-/trans-3-aminotetrahydrofuran-2-carboxylic acids (cis-/trans-FAA) having a ?-methoxy group cis to the amine. The homo-oligomers of these two diastereomeric FAAs have been prepared. Preliminary investigation of their solution secondary structures revealed that they are the same as the homo-oligomers of the parent cis-/trans-FAA with the methoxy group only being a spectator substituent.

10aAmino acids10ahelical structures10aOxygen heterocycles10aPeptides1 aGiri, Awadut, G.1 aJogdand, Ganesh, F.1 aRajamohanan, Pattuparampil, R.1 aPandey, Sunil, K.1 aRamana, Chepuri, V. uhttps://library.ncl.res.in/content/synthesis-and-structural-characterization-homochiral-homo-oligomers-cis-gamma-methoxy-000851nas a2200217 4500008004100000022001400041245010200055210006900157260007700226300001600303490000700319653002000326653001800346653002800364653001900392653002800411100002300439700002700462700002400489856012000513 2013 eng d a0947-653900aSynthesis of C-disaccharides through a one-pot alkynol cycloisomerization-reductive deoxygenation0 aSynthesis of Cdisaccharides through a onepot alkynol cycloisomer aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcNOV a15109-151140 v1910aC-disaccharides10acarbohydrates10aEpoxide-alkyne coupling10aGold catalysis10aReductive deoxygenation1 aNarute, Sachin, B.1 aRout, Jeetendra, Kumar1 aRamana, Chepuri, V. uhttps://library.ncl.res.in/content/synthesis-c-disaccharides-through-one-pot-alkynol-cycloisomerization-reductive-001015nas a2200157 4500008004100000022001400041245010100055210006900156260011000225300001400335490000700349520032700356100001900683700002400702856013100726 2013 eng d a1359-734500aSynthesis of pseudo-indoxyl derivatives via sequential Cu-catalyzed SNAr and Smalley cyclization0 aSynthesis of pseudoindoxyl derivatives via sequential Cucatalyze aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAPR a6376-63780 v493 a

ortho-Bromophenyl sec-alkyl/sec-alkenyl ketones, on reaction with sodium azide in the presence of copper salts, undergo sequential SNAr followed by Smalley cyclization to provide pseudo-indoxyl derivatives. Some of these pseudo-indoxyl derivatives exhibit interesting fluorescent properties and broad Stokes shifts.

1 aGoriya, Yogesh1 aRamana, Chepuri, V. uhttps://library.ncl.res.in/content/synthesis-pseudo-indoxyl-derivatives-sequential-cu-catalyzed-snar-and-smalley-cyclization-001014nas a2200145 4500008004100000245009000041210006900131260000800200300001400208490000700222520047000229100002600699700002400725856011900749 2016 eng d00aSynthesis of functionalized 6-hydroxy-2-oxindole derivatives by phenoxide cyclization0 aSynthesis of functionalized 6hydroxy2oxindole derivatives by phe cDEC a6264-62670 v183 aAn apparent intramolecular cross-dehydrogenative coupling of N-(3-hydrox)monoanilide of maleic esters comprising base promoted phenoxide cyclization and subsequent base-mediated aerobic oxidation was developed to synthesize a variety of 2-(6-hydroxy-2-oxoindolin-3-ylidene)-acetate derivatives. The isolation of intermediate cyclized products during the large scale reactions and their ready dehydrogenation with 1 equiv of base support this proposed two-step path.1 aReddy, Narendraprasad1 aRamana, Chepuri, V. uhttps://library.ncl.res.in/content/synthesis-functionalized-6-hydroxy-2-oxindole-derivatives-phenoxide-cyclization03455nas a2200169 4500008004100000245010400041210006900145260000800214300001200222490000700234520282900241100001703070700001903087700002403106700001503130856014003145 2024 eng d00aSynthesis, characterization, and crystal structure of 2-(2-azido­phen­yl)-3-oxo-3H-indole 1-oxide0 aSynthesis characterization and crystal structure of 22azido phen cMAR a310-3130 v803 a
An attempt to explore the reactivity of the nitro group in the presence of gold catalysis in comparison to the azide group yielded intriguing results. Surprisingly, only the nitro group exhibited reactivity, ultimately giving rise to the formation of the title isatogen.
An attempt to explore the reactivity of the nitro group in the presence of gold catalysis in comparison to the azide group yielded intriguing results. Surprisingly, only the nitro group exhibited reactivity, ultimately giving rise to the formation of the title isatogen, C14H8N4O2. In the crystal structure, weak C—H⋯O hydrogen bonds and π–π stacking inter­actions link the mol­ecules. The structure exhibits disorder of the mol­ecule.

 

1 aDhote, Pawan1 aTothadi, Srinu1 aRamana, Chepuri, V.1 aChopra, D. uhttps://library.ncl.res.in/content/synthesis-characterization-and-crystal-structure-2-2-azido%C2%ADphen%C2%ADyl-3-oxo-3h-indole-1-oxide01236nas a2200181 4500008004100000022001400041245013800055210006900193260000900262300001600271490000700287520053900294100002400833700002000857700002100877700002400898856013200922 2024 eng d a0022-326300aSynthesis of tetracyclic benzoxazolo-indol-3-ones from isatogens and arynes through a [3+2]-cycloaddition and skeletal reorganization0 aSynthesis of tetracyclic benzoxazoloindol3ones from isatogens an cOCT  a14919-149280 v893 a

The construction of an unprecedented tetracyclic benzoxazolo-indol-3-one scaffold has been executed through the [3 + 2]-cycloaddition of isatogens with arynes. The initially formed benzisoxazolo-indol-3-one intermediate undergoes a skeletal reorganization through a 1,3-sigmatropic shift/retro-Mannich reaction with the net formation of one C-N and two C-O bonds. The Lewis acid-catalyzed allylation of some of the resulting benzoxazolo-indol-3-ones resulted in oxazepino-indolones with promising photophysical properties.

1 aHalnor, Swapnil, V.1 aSingh, Maneesha1 aDhote, Pawan, S.1 aRamana, Chepuri, V. uhttps://library.ncl.res.in/content/synthesis-tetracyclic-benzoxazolo-indol-3-ones-isatogens-and-arynes-through-32-cycloaddition