Chemistry and Stereochemistry of Benzyl-Benzyl Interactions in MH+ Ions of Dibenzyl Esters upon Chemical Ionization and Collision-induced Dissociation Conditions
摘要:
Isobutane chemical ionization mass spectra of dibenzyl esters of a wide variety of aliphatic, olefinic, alicyclic and aromatic dicarboxylic acids exhibit abundant m/z 181 C14H13+ ions, indicating a highly general rearrangement process involving the formation of a new bond between the two benzyl groups. An extensive collision-induced dissociation and deuterium labeling study suggested that these ions are an almost equimolar mixture of isomeric alpha-o-tolylbenzyl, alpha-p-tolylbenzyl and p-benzylbenzyl cation structures, and this composition is identical for all the diesters examined This structural assignment of the C14H13+ ions suggests a mechanistic pathway for their generation, based on the formation of the new bond between tbe benzyl methylene group of the protonated benzoxycarbonyl and the phenyl ring of the otter ester moiety via pi- (and/or ion-neutral) and a-complexes. Stereoisomeric diesters show an unusual steric effect: trans-isomers give rise to much more abundant C14H13+ ions than the cis counterparts, This behavior is explained by stabilized proton-bridged structures of the MH+ ions of the cis-isomers. (C) 1997 by John Wiley & Sons, Ltd.
An efficient and selective method for metal- and oxidant-free deaminated esterification of tertiary amines is presented. In this protocol, ynoates play a key role to activate the Csp3−N bond through a process of in situ generation of zwitterionic salts. The transformations show that Csp3−N bond in the zwitterionic species has a lower dissociation energy than Csp2−N bond, leading to break preferentially
Phosphate mimics and methods of treatment using phosphatease inhibitors
申请人:Sugen, Inc.
公开号:US20040138255A1
公开(公告)日:2004-07-15
The invention relates to trifluoromethyl sulfonyl and trifluoromethyl sulfonamido compounds and the physiologically acceptable salts and the prodrugs thereof. These compounds are expected to modulate the activity of protein tyrosine enzymes which are related to cellular signal transduction, in particular, protein tyrosine phosphatase, and therefore are expected to be useful in the prevention and treatment of disorders associated with abnormal protein tyrosine enzyme related cellular signal transduction such as cancer, diabetes, immuno-modulation, neurologic degenerative diseases, osteoporosis and infectious diseases. The invention also relates to the use of compounds containing fluoromethyl sulfonyl groups as phosphate mimics. These mimics may be used to inhibit, regulate or modulate the activity of a phosphate binding protein in a cell.
Phosphate mimics and methods of treatment using phosphatase inhibitors
申请人:Sugen, Inc.
公开号:US06596772B1
公开(公告)日:2003-07-22
The invention relates to trifluoromethyl sulfonyl and trifluoromethyl sulfonamido compounds and the physiologically acceptable salts and the prodrugs thereof. These compounds are expected to modulate the activity of protein tyrosine enzymes which are related to cellular signal transduction, in particular, protein tyrosine phosphatase, and therefore are expected to be useful in the prevention and treatment of disorders associated with abnormal protein tyrosine enzyme related cellular signal transduction such as cancer, diabetes, immuno-modulation, neurologic degenerative diseases, osteoporosis and infectious diseases. The invention also relates to the use of compounds containing fluoromethyl sulfonyl groups as phosphate mimics. These mimics may be used to inhibit, regulate or modulate the activity of a phosphate binding protein in a cell.
Structure-based design and synthesis of small molecule protein–tyrosine phosphatase 1B inhibitors
作者:Zhu-Jun Yao、Bin Ye、Xiong-Wu Wu、Shaomeng Wang、Li Wu、Zhong-Yin Zhang、Terrence R. Burke
DOI:10.1016/s0968-0896(98)00140-0
日期:1998.10
Protein-tyrosine phosphatase (PTP) inhibitors are attractive as potential signal transduction-directed therapeutics which may be useful in the treatment of a variety of diseases. We have previously reported the X-ray structure of 1,1-difluoro-1-(2-naphthalenyl)methyl] phosphonic acid (4) complexed with the human the protein-tyrosine phosphatase 1B (PTP1B) and its use in the design of an analogue which binds with higher affinity within the catalytic site (Burke, T. R., Jr. et al. Biochemistry 1996, 35, 15989). In the current study, new naphthyldifluoromethyl phosphonic acids were designed bearing acidic functionality intended to interact with the PTP1B Arg47, which is situated just outside the catalytic pocket. This residue has been shown previously to provide key interactions with acidic residues of phosphotyrosyl-containing peptide substrates. Consistent with trends predicted by molecular dynamics calculations, the new analogues bound with 7- to 14-fold higher affinity than the parent 4, in principal validating the design rationale. (C) 1998 Elsevier Science Ltd. All rights reserved.
Strey, Karsten; Voes, Juergen, Journal of Chemical Research, Miniprint, 1998, # 3, p. 648 - 682