Synthesis, spectroscopic, and magnetic studies of copper(<scp>II</scp>) with N-protected amino acids: crystal and molecular structure of diaquatetrakis(µ-N-benzoyl-α-alaninato)-dicopper(<scp>II</scp>)
Eighteen complexes of copper(II) having the general formula CuL2·nH2O (n= 1–4) with N-protectedaminoacids (HL) have been prepared and characterized by spectroscopic methods and magnetic susceptibility measurements. These complexes belong to three types: binuclear species having bridging bidentate co-ordination through the carboxylate group, mononuclear species having symmetrical chelating bidentate
制备了十八种通式为CuL 2 · n H 2 O(n = 1-4)的铜(II)与N保护的氨基酸(HL)的配合物,并通过光谱法和磁化率测量对其进行了表征。这些络合物属于三种类型:具有通过羧酸根基团架桥双齿配位的双核物种,具有对称螯合双齿配位或桥接双齿配位且无Cu-Cu相互作用的单核物种以及具有高度不对称螯合双齿的单核物种。或通过羧酸根基团进行非螯合的不相同配位。络合物[Cu(Bz-α-AlaO)2(H2 O)} 2 ]在空间空间为P的三斜晶系中结晶,单位细胞参数a = 9.421(2), b = 9.549(2), c = 12.618(3)Å,α= 74.31(2), β= 79.21(2),γ= 88.69(2)°,并且Z =1。使用2 842个独立反射的全矩阵最小二乘优化收敛到最终R = 0.038和R '= 0.052。该配合物具有典型的一水合乙酸铜( II)型结构,平均Cu–
A convenient synthesis of difficult medium-sized cyclic peptides by Staudinger mediated ring-closure
作者:Khanh Ha、Jean-Christophe M. Monbaliu、Byron C. Williams、Girinath G. Pillai、Charles E. Ocampo、Matthias Zeller、Christian V. Stevens、Alan R. Katritzky
DOI:10.1039/c2ob25996f
日期:——
Novel, efficient and mild preparation of 7- and 8-membered cyclic di- and 10-membered cyclic tripeptides containing α-, β- or γ-amino acid residues is effected by a Staudinger-mediated ring closure. Medium-sized cyclic di- and tripeptides – recognized as difficult targets – were obtained in moderate to good yields according to a straightforward sequence. Empirical force-field calculations were undertaken
Staudinger介导的闭环可以有效,温和地制备含有α-,β-或γ-氨基酸残基的7元和8元环状二元和10元环状三肽。中型环状二肽和三肽(被认为是困难的靶标)是根据简单的顺序以中等到良好的产率获得的。进行了经验力场计算,以确定它们的构象行为,并显示出与X射线结果高度相似的水平。在B3LYP / 6-31 + G **理论水平的计算研究提供了有关叠氮基肽硫酯环化的序列,环大小和取代对活化障碍的影响的信息。
Hydroxyacyl-amino acids and their polymers
申请人:TEE PAK INC
公开号:US02786045A1
公开(公告)日:1957-03-19
New type of selectively acting organophosphorus insecticides and acaricides
作者:T. A. Mastryukova、A. E. Shipov、E. B. Gorbenko、M. P. Shabanova、K. N. Savchenko、Yu. S. Kagan、M. I. Kabachnik
The beta-alanine residue of the title compound, C5H8ClNO3, has a ggt folded conformation, which is mainly stabilized through intermolecular N-H...O=C (amide-acid) and O- H...O=C (acid-amide) hydrogen bonds. In addition, a cis conformation is found for the Cl-CH2-C(=O)-NH torsion angle, which is associated with the presence of an intramolecular hydrogen bond.