Detrifluoroacetylation Reaction of Trifluoromethyl-β-diketones: Facile Method for the Synthesis of Succinimide Derivatives and 1,4-Diketones
作者:Li-Hua Wang、Jing Zhao
DOI:10.1002/ejoc.201800680
日期:2018.8.23
A detrifluoroacetylation of trifluoromethyl‐β‐diketones has been developed, which allows for the synthesis of succinimides and 1,4‐diketones through cascade Michael addition/retro‐Claisen reaction and nucleophilic substitution/retro‐Claisen reaction.
Palladium-catalyzed coupling of amides and cyclopropanols for the synthesis of γ-diketones
作者:Lili Fang、Shuqi Jia、Shuaixin Fan、Jin Zhu
DOI:10.1039/d3cc02888g
日期:——
method has been developed for the coupling of amides and cyclopropanols to γ-diketones, through simultaneous C–N and C–C activation. Heteroatom ligand exchange and heteroatom-to-carbon ligation mode switching enable the achievement of molecular cross-coupling in an amide N-atom structural context-dependent manner, avoiding any stoichiometric organometallic reagent or base.
Synthesis of 1,4-keto esters and 1,4-diketones via palladium-catalyzed acylation of siloxycyclopropanes. Synthetic and mechanistic studies
作者:Tsutomu Fujimura、Satoshi Aoki、Eiichi Nakamura
DOI:10.1021/jo00008a043
日期:1991.4
The reaction of a variety of siloxycyclopropanes with acid chlorides in the presence of a catalytic amount of a palladium/phosphine complex gives 1,4-dicarbonyl compounds to good yield. 1-Alkoxy-1-(trialkylsiloxy)-cyclopropanes react with both aromatic and aliphatic acid chlorides in chloroform to give 1,4-keto esters. Synthesis of 1,4-diketones by the acylation of 1-alkyl- or 1-aryl-1-siloxycyclopropanes has been achieved by carrying out the reaction if HMPA under 10-20 atm of carbon monoxide. Kinetics studies and product analysis revealed the unique mechanism of this reaction, which involves rate-determining cleavage of the strained cyclopropane carbon-carbon bond with a coordinatively unsaturated acylpalladium chloride complex. Ab initio calculations of hydroxylated cyclopropane model compounds showed that the unique reactivities of the siloxycyclopropanes may be correlated with the molecular orbital properties of these compounds rather than their ground-state structural properties.
Acylguanidine inhibitors of β-secretase: Optimization of the pyrrole ring substituents extending into the S1 and S3 substrate binding pockets
作者:Derek C. Cole、Joseph R. Stock、Rajiv Chopra、Rebecca Cowling、John W. Ellingboe、Kristi Y. Fan、Boyd L. Harrison、Yun Hu、Steve Jacobsen、Lee D. Jennings、Guixian Jin、Peter A. Lohse、Michael S. Malamas、Eric S. Manas、William J. Moore、Mary-Margaret O’Donnell、Andrea M. Olland、Albert J. Robichaud、Kristine Svenson、JunJun Wu、Eric Wagner、Jonathan Bard
DOI:10.1016/j.bmcl.2007.12.010
日期:2008.2
Proteolytic cleavage of amyloid precursor protein by beta-secretase (BACE-1) and gamma-secretase leads to formation of beta-amyloid (A beta) a key component of amyloid plaques, which are considered the hallmark of Alzheimer's disease. Small molecule inhibitors of BACE-1 may reduce levels of A beta and thus have therapeutic potential for treating Alzheimer's disease. We recently reported the identification of a novel small molecule BACE-1 inhibitor N-[2-(2,5-diphenyl-pyrrol-1-yl)-acetyl]guanidine (3.a.1). We report here the initial hit-to-lead optimization of this hit and the SAR around the aryl groups occupying the S-1 and S-2' pockets leading to submicromolar BACE-1 inhibitors. (C) 2007 Elsevier Ltd. All rights reserved.