CAN-Catalyzed Rapid C–O Bond Formation towards α-Aminoxylation of Ketones
作者:Ning Jiao、Peng Feng、Song Song、Li-He Zhang
DOI:10.1055/s-0034-1379102
日期:——
A simple and efficient approach towards α-oxyaminated ketones has been developed through CAN-catalyzed C–O bond formation with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). The environmentally friendly transformation is practical due to the use of commercial available catalyst, easy operating procedures, the broad substrate scope, and short reaction time.
通过 CAN 催化的 C-O 键与 2,2,6,6-四甲基哌啶-1-氧基(TEMPO)形成,开发了一种简单有效的 α-氧胺化酮方法。由于使用市售催化剂、操作简单、底物范围广、反应时间短,这种环保转化是可行的。
Visible-light-driven Oxidation of 1,3-Dicarbonyl Compounds via Catalytic Disproportionation of TEMPO by Photoredox Catalysis
作者:Takashi Koike、Yusuke Yasu、Munetaka Akita
DOI:10.1246/cl.2012.999
日期:2012.9.5
Visible light irradiation of a mixture of 1,3-dicarbonyls and 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) in the presence of photoredox catalysts, [Ru(bpy)3]2+ and [Ir(ppy)2(dtbbpy)]+ (bpy: 2,2′-bipyridine, ppy: 2-phenylpyridine, dtbbpy: 4,4′-di-tert-butyl-2,2′-bipyridine), afforded two types of oxidized products, i.e., α-oxyaminated products from acyclic 1,3-dicarbonyls and oxidatively dimerized products from cyclic 1,3-dicarbonyls. The Ir catalyst turned out to be more active than the Ru catalyst. This is a new photocatalytic oxidation of 1,3-dicarbonyls based on a single-electron-transfer process mediated by excited photoredox catalysts.
Visible-light-promoted aerobic metal-free aminothiocyanation of activated ketones
作者:Pan-Feng Yuan、Qing-Bao Zhang、Xiao-Ling Jin、Wen-Long Lei、Li-Zhu Wu、Qiang Liu
DOI:10.1039/c8gc02720j
日期:——
A direct, redox-neutral, highly atom-economical and metal-free aerobic method for the synthesis of multi-substituted olefins via simply coupling ammonium thiocyanate with activated ketones is described. A series of multi-substituted olefins could be easily and efficiently obtained in excellent yields by using low-toxicity and inexpensive ammonium thiocyanate as an amine and thiocyanate source, and
Friedel–Crafts reaction of indoles with vicinal tricarbonyl compounds generated in situ from 1,3-dicarbonyl compounds and TEMPO: highly selective synthesis of tertiary alcohols
indoles with vicinal tricarbonyl compoundsgenerated in situfrom 1,3-dicarbonyl compounds, which produces indole substituted tertiary alcohols in good to excellent yields and with good functional group tolerance, has been developed. The mechanistic pathway for this process involves the initial disproportionation of TEMPO, α-oxyamination of the 1,3-dicarbonyl compound followed by N–O bond cleavage to
Alkoxyamines by Reaction of 2,2,6,6-Tetramethylpiperidine-1-oxoammonium Tetrafluoroborate with Enolates
作者:Hans J. Schäfer、Matthias Schämann
DOI:10.1055/s-2004-829073
日期:——
Alkoxyamines are prepared from the oxoammoniumsalt of TEMPO and enolates in one step and metal free in 47-89% yield. One of these alkoxyamines (6b) was used to polymerize styrene with a polydispersity index (PDI)=1.42 (125 °C) and 1.49 (105°C).