- Total synthesis of tetracyclic kynurenic acid analogues isolated from chestnut honey
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A short and efficient synthesis of novel tetracyclic Kynurenic acid analogues, isolated from chestnut honey, is described. The crucial step of the strategy was a MW-assisted cyclization of enamines of ethyl dioxohexahydropyrrolizine and 2,3-dioxooctahydroindolizine carboxylates to obtain 2,3,6,11b-tetrahydro-1H-pyrrolizino[2,1-b]quinoline-5,11-dione and 5,8,91,011,11a-hexahydroindolizino[2,1-b]quinoline-6,12-dione, respectively. Because of its modular nature, the synthetic strategy can have value as a general method for the preparation of compounds containing these new heterocyclic scaffolds.
- Cincinelli, Raffaella,Beretta, Giangiacomo,Dallavalle, Sabrina
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- A (-)-sparteine-directed highly enantioselective synthesis of boroproline. Solid- and solution-state structure and properties
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(Chemical Equation Presented) A two-step, direct asymmetric synthesis of the trifluoroacetate ammonium salt of boroproline is reported. (-)-Sparteine-mediated lithiation of N-Boc-pyrrolidine afforded N-Boc-aminoboronic acid in good yield and enantioselectivity as determined by HPLC (pinanediol ester). Deprotection using TFA yielded the ammonium salt; full characterization data are presented, and the structure in aqueous solution and the occurrence of a B-N species are discussed.
- Batsanov, Andrei S.,Grosjean, Christophe,Schuetz, Thorben,Whiting, Andrew
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- A General C(sp3)-C(sp3) Cross-Coupling of Benzyl Sulfonylhydrazones with Alkyl Boronic Acids
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A general transition-metal-free cross-coupling between benzylic sulfonylhydrazones and 1°, 2°, or 3° alkyl boronic acids is reported. The base-promoted reaction is operationally simple and exhibits a broad substrate scope to forge a variety of alkyl-alkyl bonds, including between sterically encumbered secondary and tertiary sp3-carbons. The ability of this method to simplify retrosynthetic analysis is exemplified by the improved synthesis of multiple medicinally relevant scaffolds.
- Merchant, Rohan R.,Lopez, Jovan A.
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supporting information
p. 2271 - 2275
(2020/03/13)
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- Proline boric acid compound and preparation method and applications thereof
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The invention provides a compound whose structure is shown as a formula (I) or a salt thereof. The compound is a proline boric acid proteasome inhibitor compound, and has good proteasome inhibitory activity and excellent druggability. The structural formula of the compound is shown as the formula (I).
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Paragraph 0040; 0041
(2019/01/06)
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- Synthesis and biological activity of peptide proline-boronic acids as proteasome inhibitors
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On the basis of the application of proline-boronic acid as pharmacophore in the kinase inhibitors and our previous research results, using proline-boronic acid as warhead, two series of peptide proline-boronic acids, dipeptide proline-boronic acids (I) and tripeptide proline-boronic acids (II), were designed and synthesized. All the synthesized compounds were first evaluated for their biological activity against MGC803 cell, and then, the best compound II-7 was selected to test its anti-tumor spectrum on six human tumor cell lines and proteasome inhibition against three subunits. The results indicated that series II have much better biological activities than series I. The compound II-7 exhibited not only excellent biological activities with IC50 values of nM level in both cell and proteasome models, but also much better subunit selectivity. Thus, proline-boronic acid as warhead is reasonable in the design of proteasome inhibitors.
- Han, Liqiang,Wen, Yanzhao,Li, Ridong,Xu, Bo,Ge, Zemei,Wang, Xin,Cheng, Tieming,Cui, Jingrong,Li, Runtao
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p. 4031 - 4044
(2017/07/05)
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- FIBROBLAST ACTIVATION PROTEIN INHIBITOR COMPOUNDS AND METHODS
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Amino terminus-blocked peptide boronate compounds of Formulas I and II are useful for inhibiting Fibroblast Activation Protein (FAP) and other proteases, and for treating disorders mediated by FAP. Methods of using the amino terminus blocked peptide boronate compounds, and stereoisomers, tautomers, solvates and pharmaceutically acceptable salts thereof, for in vitro, in situ, and in vivo diagnosis, prevention or treatment of such disorders in mammalian cells, or associated pathological conditions are disclosed.
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Page/Page column 25
(2008/06/13)
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- HETEROCYCLIC BORONIC ACID COMPOUNDS
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Dipeptidyl peptidase IV (DPP-IV)-inhibiting compounds are provided that have formula I: wherein n is 1 to 3; X is CH2; S; O; CF2 or C (CH3)2; Z is H; halogen; hydroxyl; (C1-6)alkoxy; (C1-12)alkyl; (C3-12)cycloalkyl; phenyl; or heteroaryl; where the phenyl and heteroaryl groups are optionally mono- or independently plurisubstituted with R7; optionally, X together with an adjacent ring carbon and Z form a fused cyclopropyl; and optionally, one of the bonds in the ring containing X is a double bond; and CriRii, R1, R1, R3, R4 and R5 are as described herein. Methods for preparing these compounds, and methods for treating diabetes, especially Type II diabetes, and other related diseases are described using the compounds of formula I in pharmaceutical compositions which contain these compounds. Pharmaceutical compositions which contain combinations of these compounds with other antidiabetic agents are also described herein.
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Page/Page column 114-115
(2008/06/13)
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- Direct selection for catalysis from combinatorial antibody libraires using a boronic acid probe: Primary amide bond hydrolysis
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This report describes a joint hybridoma and combinatorial antibody library approach to elicit catalysts for primary amide bond hydrolysis. By immunization with a trigonal boronic acid hapten 3a and construction of a Fab (antigen-binding fragment) library, a diastereoselective catalyst for hydrolysis of the tripeptide primary amide substrate la was selected. In contrast, no antibody catalyst was isolated by standard hybridoma methods of monoclonal antibody production following immunizations with hapten 3a. The active Fab, BL25, obeys Michaelis-Menten kinetic behavior (k(cat)/k(uncat) ca. 4 x 104, K(m) = 150 μM) and is competitively inhibited by a boronic acid hapten analog 3b (K(i) = 9 μM). Kinetic and binding studies both point to Fab selection of a hydrated tetrahedral anionic form of the boronic acid hapten 3a which serves to mimic the putative transition state 4 for catalysis of water addition to the primary amide bond. Fab-BL25 exhibits exquisite substrate selectivity, as a methyl ester analog of 1a is not accepted as a substrate. This work emphasises the power of the direct selection strategy when linked to screening of antibody combinatorial libraries and discloses the utility of boronic acids as haptens in acyl transfer processes.
- Gao, Changshou,Lavey, Brian J.,Lo, Chih-Hung L.,Datta, Anita,Wentworth Jr., Paul,Janda, Kim D.
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p. 2211 - 2217
(2007/10/03)
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