- ENZYMATIC SYNTHESIS OF ENANTIOMERICALLY ENRICHED DERIVATIVES OF CIS- AND TRANS-CYCLOPENTANE-1,2-DIAMINES
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SUMMARY The present invention relates to the enzymatic resolution of cis-and trans-cyclopentane-1,2-diamine derivatives to obtain enantiomerically pure or enriched compounds, a method for the preparation of the starting materials of that procedure, the pr
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Page/Page column 19-20
(2011/05/14)
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- Enzymatic dynamic kinetic resolution of (±)-cis-N-(Alkoxycarbonyl) cyclopentane-1,2-diamines based on spontaneous racemization
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Lipase B from Candida antarctica is an excellent catalyst for the enantioselective acetylation of different (±)-cis-N-(alkoxycarbonyl) cyclopentane-1,2-diamines. Depending on the alkoxycarbonyl group, a simple kinetic resolution (Boc-derivative) or an interesting dynamic kinetic resolution (DKR with Cbz-, Alloc, and ethoxycarbonyl derivatives) has been developed. Racemization for the DKR occurred due to the N,N′ intramolecular migration of the alkoxycarbonyl group.
- Quijada, F. Javier,Gotor, Vicente,Rebolledo, Francisca
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supporting information; experimental part
p. 3602 - 3605
(2010/11/05)
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- cis-Cyclopentyl PNA (cpPNA) as constrained chiral PNA analogues: stereochemical dependence of DNA/RNA hybridization.
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DNA/RNA hybridization studies of PNA-T oligomers with cis-(1S,2R/1R,2S)-cyclopentyl units in the backbone show stereochemistry dependent binding with RNA/DNA discrimination.
- Govindaraju,Kumar, Vaijayanti A,Ganesh, Krishna N
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p. 860 - 861
(2007/10/03)
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- (1S,2R/1R,2S)-cis-cyclopentyl PNAs (cpPNAs) as constrained PNA analogues: Synthesis and evaluation of aeg-cpPNA chimera and stereopreferences in hybridization with DNA/RNA
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Conformationally constrained chiral PNA analogues were designed on the basis of stereospecific imposition of a 1,2-cis-cyclopentyl moiety on an aminoethyl segment of aegPNA. It is known that the cyclopentane ring is a relatively flexible system in which the characteristic puckering dictates the pseudoaxial/pseudoequatorial dispositions of substituents. Hence, favorable torsional adjustments are possible to attain the necessary hybridization- competent conformations when the moiety is imposed on the conventional PNA backbone. The synthesis of the enantiomerically pure 1,2-cis-cyclopentyl PNA monomers (10a and 10b) was achieved by stereoselective enzymatic hydrolysis of a key intermediate ester 2. The chiral (1S,2R/1R,2S)-aminocyclopentylglycyl thymine monomers were incorporated into PNA oligomers at defined positions and through the entire sequence. Hybridization studies with complementary DNA and RNA sequences using UV-Tm measurements indicate that aeg-cpPNA. chimera form thermally more stable complexes than aegPNA with stereochemistry-dependent selective binding of cDNA/RNA. Differential gel shift retardation was observed on hybridization of aeg-cpPNAs with complementary DNA.
- Govindaraju,Kumar, Vaijayanti A.,Ganesh, Krishna N.
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p. 5725 - 5734
(2007/10/03)
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- Heterocycle derivatives and drugs
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There is provided an excellent novel analgesic having an analgesic effect which is effective widely against a pain including a chronic pain or an allodynia accompanied with herpes zoster by acting on a nociceptin receptor. The present invention relates to a compound represented by the following formula: or a salt thereof. In the formula, X and Y are same or different and each represents a nitrogen atom or CH; R1 represents a hydrogen atom or alkyl and the like; A1 and A2 are same or different and each represents a single bond or a divalent aliphatic hydrocarbon group; Q represents a single bond, cycloalkylene group, phenylene group or divalent heterocyclic group; R2A, R2B, R2C and R2D are same or different and each represents a hydrogen atom, alkyl or phenyl; E represents a ethenylene group or —NRCO— (in which R is hydrogen or alkyl) and the like; R3 represents a phenyl group or a heterocyclic group; R4 and R5 are same or different and each represents a hydrogen atom, alkyl, alkoxy, aralkyloxy, halogen, nitro, hydroxy, alkoxycarbonyl, —NR6R7 (in which R6 and R7 are same or different and each represents a hydrogen atom or alkyl) and the like.
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