revealed as the major pathway. DFT calculations indicate that the formation of a radical anion via nucleophilic addition of alkoxide to the aryl radical is the key step in determining the observed chemoselectivity.
开发了一种新的芳基甲基砜和醇的正式交叉偶联,通过 S RN 1 途径提供烷基芳基醚。使用这种方法作为关键步骤,有效地制备了两种市售的抗结核药物。二甲基阴离子引发的自由基链过程被揭示为主要途径。DFT 计算表明,通过醇盐与芳基的亲核加成形成自由基阴离子是确定观察到的化学选择性的关键步骤。
FUSED HETEROCYCLIC COMPOUNDS
申请人:TANIGUCHI Takahiko
公开号:US20110319394A1
公开(公告)日:2011-12-29
The present invention provides a compound which has the effect of PDE inhibition, and which is useful as an agent for preventing or treating schizophrenia. The compound is represented by the formula (I):
wherein the symbols are defined in the specification.
Ceramide-Templated Macrolactams: Total Synthesis and Biological Evaluation of Macrocyclic α-Galactosylceramide Analogues and their Aglycons
作者:Jonas Janssens、Johan Van der Eycken、Serge Van Calenbergh
DOI:10.1002/ejoc.201801839
日期:2019.3.31
We present the total synthesis of macrocyclic analogues of the immunomodulating glycolipid alpha-GalCer (KRN7000), along with the corresponding macrocyclic aglycons. Their structures are inspired by the conformation of alpha-GalCer when bound to the antigen presenting glycoprotein CD1d. The applied synthesis plan, involving either ring-closing metathesis or ruthenium-catalyzed azide-alkyne cycloaddition
Practical Methylenation Reaction for Aldehydes and Ketones Using New Julia-Type Reagents
作者:Kaori Ando、Takahisa Kobayashi、Nariaki Uchida
DOI:10.1021/acs.orglett.5b01049
日期:2015.5.15
A new Julia-type methylenation reagent, 1-methyl-2-(methylsulfonyl)benzimidazole (1e), reacts with a variety of aldehydes and ketones in the presence of either NaHMDS (−55 °C to rt) or t-BuOK (rt, 1 h) in DMF to give the corresponding terminal alkenes in high yields. The byproducts are easily removed, and the reaction conditions are mild and practical.
The methylenation reagent 1-methylbenzimidazol-2-yl methyl sulfone 2 reacts with various aldehydes and ketones in the presence of t-BuOK (room temperature, 1 h) in dimethylformamide to give the corresponding terminal alkenes generally in high yields. For sensitive substrates, the reaction is better carried out at low temperature using sodium hexamethyldisilazide in 1,2-dimethoxyethane. The byproduct