InCl<sub>3</sub>/Me<sub>3</sub>SiBr-Catalyzed Direct Coupling between Silyl Ethers and Enol Acetates
作者:Yoshiharu Onishi、Yoshihiro Nishimoto、Makoto Yasuda、Akio Baba
DOI:10.1021/ol200875m
日期:2011.5.20
A combined Lewis acid catalyst of InCl3 and Me3SiBr promoted the direct use of enol acetates in the coupling with low-reactive silyl ethers, in which functional groups including ketones and aldehydes survived. Sterically hindered silyl ethers such as ROSiEt3, ROSiPh3, ROSit-BuMe2, and ROSii-Pr3 were also applicable.
N-Fluoropyridinium salts provide a new system of fluorinatingagents by which a wide range of nucleophilic substrates differing in reactivity can be fluorinated due to the varying degree of fluorinating power and also fluorinated very selectively through structural alteration. The scope of selective fluorination should be broadened considerably on the basis of the present results. The N-fluoropyridinium
Cycloalkyl, lactam, lactone and related compounds, pharmaceutical compositions comprising same, and methods for inhibiting beta-amyloid peptide release and/or its synthesis by use of such compounds
申请人:——
公开号:US20020045747A1
公开(公告)日:2002-04-18
Disclosed are compounds which inhibit &bgr;-amyloid peptide release and/or its synthesis, and, accordingly, have utility in treating Alzheimer's disease. Also disclosed are pharmaceutical compositions comprising a compound which inhibits &bgr;-amyloid peptide release and/or its synthesis as well as methods for treating Alzheimer's disease both prophylactically and therapeutically with such pharmaceutical compositions.
Reactions between acyclic (E)-allylic acetates and arylboronic acids in the presence of a palladium catalyst prepared from Pd(OAc)(2), phenanthroline (or bipyridine), and AgSbF(6) (1:1.2:1) proceeded with excellent gamma-selectivity to afford allyl-aryl coupling products with E-configuration. The reactions of alpha-chiral allylic acetates took place with excellent alpha-to-gamma chirality transfer