Intramolecular O,N-acyl transfer via cyclic intermediates of nine and twelve members. Models for extensions of the amine capture strategy for peptide synthesis
solution, with exception of the nitro derivatives, where the NH tautomer is present. In the solid state the tautomericequilibrium is strongly shifted to the NH form. Only for the 5-Br derivative of one compound was the reverse relationship found. According to the results of experimental charge density investigations, two intramolecular H-bonds in the 5-methoxy derivative of 2-hydroxy-N-(2′-hydroxybenzylideno)benzylamine)
研究了一系列十六种席夫碱(水杨醛和芳基胺的衍生物),以揭示取代基和接头长度对形成的H键性质的影响。理论上,两组化合物,即2-(2-羟基苄基亚胺基)苯酚的衍生物和2-羟基-N-(2-羟基苄基亚胺基)苄基胺,可以使用存在于其中的一个或两个羟基来形成不同类型的H键。分子。其他两组化合物,即4-(2-羟基苄基亚胺基)苯酚的衍生物和N-(2-羟基苄基亚胺基)苄基胺,只能形成一种H键。15 N和13证实了这一点1 C NMR实验表明,在所有情况下均仅形成传统的H键结合的六元螯合环。环中氢原子的位置取决于取代基和相。通常,除了存在NH互变异构体的硝基衍生物以外,OH H键形式在溶液中占主导地位。在固态中,互变异构平衡强烈地转变为NH形式。仅发现一种化合物的5-Br衍生物具有相反的关系。根据实验电荷密度研究的结果,2-羟基-N的5-甲氧基衍生物中的两个分子内H键-(2'-羟基苄基亚氨基)苄胺)在电荷密度特
Phosphatase inhibitors—III. Benzylaminophosphonic acids as potent inhibitors of human prostatic acid phosphatase
作者:Scott A. Beers、Charles F. Schwender、Deborah A. Loughney、Elizabeth Malloy、Keith Demarest、Jerold Jordan
DOI:10.1016/0968-0896(96)00186-1
日期:1996.10
phenylphosphonic acid, and a rigid conformer produced by an internal salt bridge between the phosphonate and the alpha-amino group. Replacement of the phosphonic acid moiety with a phosphinic or carboxylic acid as well as deletion of the benzyl substitution of the alpha-amino group led to great reductions in potency.
Syntheses, characterizations, X-ray crystal structures, and antibacterial activities of Co(II), Ni(II), and Zn(II) complexes of the Schiff base derived from 5-nitro-2-hydroxybenzaldehyde and benzylamine
synthesized and characterized. [CoIIL2(bzln)2] (1) was initially formedfrom the reaction of H2L1 (N,N′-bis(5-nitrobenzaldehyde)-2-aminobenzylamine = H2L1), with CoII(CH3COO)2·4H2O in the presence of benzylamine. The X-ray crystal structure of 1 revealed that HL was formedfrom the hydrolysis of H2L1 and the recondensation of benzylamine with 2-hydroxy-5-nitrobenzaldehyde produced in H2L1 hydrolysis