Substituted tetrahydrofuroyl-1-phenylalanine derivatives as potent and specific VLA-4 antagonists
摘要:
A series of substituted tetra hydrofuroyl-1-phenylalanine derivatives was prepared and evaluated as VLA-4 antagonists. Substitution of the a carbon of the tetrahydrofuran with aryl groups increased the specificity for VLA-4 versus alpha(4)beta(7) while amide substitution increased the potency of the series without increasing the specificity. Substitution of the P carbon of the tetrahydrofuran with keto or amino groups slightly improved the specificity for VLA-4 versus alpha(4)beta(7) but with a significant loss in binding affinity for VLA-4. (C) 2002 Elsevier Science Ltd. All rights reserved.
presents the first example of the Pd-catalyzed cascade reactions of 5-oxohexanenitrile with arylboronicacids, affording important synthon 2-methylpyridines that can be further translated through C(sp3)-H functionalization to construct pyridine derivatives. Furthermore, this chemistry allows 5-oxo-5-arylpentanenitrile to react with arylboronicacids to provide unsymmetrical 2,6-diarylpyridines. This protocol
Nickel-Catalyzed Reductive Electrophilic Ring Opening of Cycloketone Oxime Esters with Aroyl Chlorides
作者:Decai Ding、Chuan Wang
DOI:10.1021/acscatal.8b03930
日期:2018.12.7
of cycloketone oxime esters with aromatic acid chlorides in assistance of Mn as reductant. Notably, complete regioselectivity can be achieved in this C–C bond cleavage reaction, providing an efficient access to a variety of cyanoketones under cyanide-free conditions. A radical reaction pathway was proposed on the basis of the results of the mechanisticprobing experiments.
C−C Bond-Forming Strategy by Manganese-Catalyzed Oxidative Ring-Opening Cyanation and Ethynylation of Cyclobutanol Derivatives
作者:Rongguo Ren、Zhen Wu、Yan Xu、Chen Zhu
DOI:10.1002/anie.201510973
日期:2016.2.18
cyano C1 unit and ethynyl C2 unit are regiospecifically introduced to the γ‐position of ketones at room temperature, providing a mild yet powerful method for production of elusive aliphatic nitriles and alkynes. All transformations described are based on a common sequence: 1) oxidative ring‐opening of cyclobutanol substrates by C−C bond cleavage; 2) radical addition to triple bonds bearing an arylsulfonyl
The first example of the Pd-catalyzed addition of organoboron reagents to dinitriles, as an efficient means of preparing 2,5-diarylpyrroles and 2,6-diarylpyridines, has been discussed here. Furthermore, the highly selective carbopalladation of dinitriles with organoboron reagents to give long-chain ketonitriles has been developed as well. Based on the broad scope of substrates, excellent functional
be prepared by the titanium(III)‐catalyzed reductive radical cyclization of iminonitriles. Depending on the position of the nitrile at the imine carbon or nitrogen, cyclic aminoketones or pyrrolidin‐3‐ones with a tetrasubstituted α‐carbon can be formed in up to quantitative yield. In the latter case, the imine condensation and TiIII catalysis correspond to a formal [4+1] cycloaddition.