595-39-1Relevant articles and documents
SN2 displacement at the quaternary carbon center: A novel entry to the synthesis of α,α-disubstituted α-amino acids This Letter is dedicated to the late Professor Harry Wasserman, a great chemist as well as a splendid artist
Ishihara, Kotaro,Hamamoto, Hiromi,Matsugi, Masato,Shioiri, Takayuki
supporting information, p. 3169 - 3171 (2015/05/27)
A novel method for the SN2 reaction on quaternary carbon atoms using bis(p-nitrophenyl)phosphorazidate has been developed. Chiral tertiary alcohols were directly converted into the corresponding chiral tertiary azides with complete inversion of configuration. Several α,α-disubstituted α-amino esters or amino acids were prepared through the conversion of azides to the corresponding amines by catalytic hydrogenation.
Synthesis and biological activity of nociceptin/orphanin FQ analogues substituted in position 7 or 11 with Cα,α-dialkylated amino acids
Arduin, Marika,Spagnolo, Barbara,Calo, Girolamo,Guerrini, Remo,Carra, Giacomo,Fischetti, Carmela,Trapella, Claudio,Marzola, Erika,McDonald, John,Lambert, David G.,Regoli, Domenico,Salvadori, Severo
, p. 4434 - 4443 (2008/03/13)
Previous structure-activity and NMR studies on nociceptin/orphanin FQ (N/OFQ) demonstrated that Aib substitution of Ala7 and/or Ala11 increases the peptide potency through an alpha helix structure induction mechanism. On these bases we synthesised and evaluated pharmacologically in the mouse vas deferens assay a series of N/OFQ-NH2 analogues substituted in position 7 and 11 with Cα,α-disubstituted cyclic, linear and branched amino acids. None of the 20 novel N/OFQ analogues produced better results than [Aib7]N/OFQ-NH2. Thus, this substitution was combined with other chemical modifications known to modulate peptide potency and/or efficacy generating compound 21 [Nphe1Aib7Arg14Lys15]N/OFQ-NH2 (coded as UFP-111), compound 22 [(pF)Phe4Aib7Arg14Lys15]N/OFQ-NH2 (UFP-112) and compound 23 [Phe1Ψ(CH2-NH)Gly2(pF)Phe4Aib7Arg14Lys15]N/OFQ-NH2 (UFP-113). These novel peptides behaved as highly potent NOP receptor ligands showing full (UFP-112) and partial (UFP-113) agonist and pure antagonist (UFP-111) activities in a series of in vitro functional assays performed on pharmacological preparations expressing native as well as recombinant NOP receptors.
Studies on optically active amino acids. VI. Studies on alpha-alkyl-alpha-amino acids. II. Resolution of some alpha-methyl-alpha-amino acids through 1-menthyl ester.
Terashima,Achiwa,Yamada
, p. 1399 - 1407 (2007/10/05)
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