investigations are consistent with an oxidative addition/olefin insertion/reductive elimination mechanism. The incorporated methylene sulfide substituent can undergo a variety of further reactions to increase molecular diversity and complexity. These results demonstrate that thioester derivatives can be used as powerful buildingblocks for the assembly of complex scaffolds.
Preparation of cyclic imides from alkene-tethered amides: application of homogeneous Cu(<scp>ii</scp>) catalytic systems
作者:Zhenghui Liu、Peng Wang、Hualin Ou、Zhenzhong Yan、Suqing Chen、Xingxing Tan、Dongkun Yu、Xinhui Zhao、Tiancheng Mu
DOI:10.1039/c9ra10422d
日期:——
A Cu-based homogeneous catalytic system was proposed for the preparation of imides from alkene-tethered amides. Here, O2 acted as a terminal oxidant and a cheap and easily available oxygen source. The cleavage of CC bonds and the formation of C–N bonds were catalyzed by Cu(II) salts with proper nitrogen-containing ligands under 100 °C. The synthesis approach has potential applications in pharmaceutical
提出了一种基于铜的均相催化体系,用于从烯烃束缚酰胺制备酰亚胺。在这里,O 2充当末端氧化剂和廉价且容易获得的氧源。在 100 °C 下,具有适当含氮配体的 Cu( II ) 盐催化C C 键的断裂和 C-N 键的形成。该合成方法在药物合成中具有潜在的应用。此外,放大实验证实了实际适用性。
Chiral Hypervalent Iodine(III) Catalyst Promotes Highly Enantioselective Sulfonyl- and Phosphoryl-oxylactonizations
An efficient enantioselective hypervalentiodine promoted oxylactonization of 4-pentenoic acids has been achieved using stoichiometric or a catalytic amount of chiral aryl-λ3-iodane. This reaction provides straightforward access to a wide range of sulfonyloxy- and phosphoryloxy-γ-butyrolactones in respectable yields with moderate to excellent enantioselectivities.
N-Cycloalkanoyl-l-Phenylalanine Derivatives as VCAM/VLA-4 Antagonists
作者:Achyutharao Sidduri、Jefferson W Tilley、Kenneth Hull、Jian Ping Lou、Gerry Kaplan、Allen Sheffron、Li Chen、Robert Campbell、Robert Guthrie、Tai-Nan Huang、Nicholas Huby、Karen Rowan、Virginia Schwinge、Louis M Renzetti
DOI:10.1016/s0960-894x(02)00386-4
日期:2002.9
A systematic structure-activity relationship investigation of the lead compound I resulted the identification of several N-[(substituted alkyl)cycloalkanoyl]-4-[((2,6-dichlorophenyl)carbonyl)amino]-L-phenylalanine derivatives as potent VCAM/VLA-4 antagonists. The data are consistent with a model of these compounds in which these alkanoylphenylalanines reside in a compact gauche (-) bioactive conformation. (C) 2002 Elsevier Science Ltd. All rights reserved.
Neighboring group participation in Lewis acid-promoted [3 + 4] and [3 + 5] annulations. The stereocontrolled synthesis of tricyclic ethers
作者:Gary A. Molander、Kimberly O. Cameron
DOI:10.1021/jo00074a018
日期:1993.10
A variety of 1,4- and 1,5-keto aldehydes derived from cycloalkanes are coupled with the bis(trimethylsilyl) enol ether of methyl acetoacetate in the presence of either TMSOTf or TrSbCl6 to generate tricyclic ethers. The reactions proceed with excellent regiochemical control by a mechanism involving neighboring group participation. This mechanism involves initial formation of a bicyclic oxocarbenium ion intermediate from the keto aldehyde substrates. The geometries of selected bicyclic intermediates have been optimized using the AM1 method allowing successful prediction of the stereochemical outcomes in the cyclization in most cases. Epimerization of alpha-chiral keto aldehyde substrates does not appear to occur in these Lewis acid-promoted annulation reactions.