Hydroalkylation of Unactivated Olefins via Visible-Light-Driven Dual Hydrogen Atom Transfer Catalysis
作者:Guangyue Lei、Meichen Xu、Rui Chang、Ignacio Funes-Ardoiz、Juntao Ye
DOI:10.1021/jacs.1c05852
日期:2021.7.28
hydroalkylation of olefins enabled by hydrogen atom transfer (HAT) catalysis represents a straightforward means to access C(sp3)-rich molecules from abundant feedstock chemicals without the need for prefunctionalization. While Giese-type hydroalkylation of activated olefins initiated by HAT of hydridic carbon–hydrogen bonds is well-precedented, hydroalkylation of unactivated olefins in a similar fashion
通过氢原子转移 (HAT) 催化实现的烯烃自由基加氢烷基化代表了一种直接获得 C( sp 3)-丰富的分子来自丰富的原料化学品,无需预官能化。虽然由氢化碳-氢键的 HAT 引发的活性烯烃的 Giese 型加氢烷基化是有先例的,但未活化烯烃以类似方式的加氢烷基化仍然难以捉摸,主要是由于缺乏克服固有极性不匹配的通用方法。设想。在这里,我们报告了使用可见光驱动的双 HAT 催化来实现这一目标,其中催化量的胺硼烷和原位生成的硫醇分别用作氢原子提取物和供体。该反应是完全原子经济的,具有广泛的范围。
Photoinduced Atom Transfer Radical Addition Reaction of Olefins with α-Bromo Carbonyls
transfer radical addition (ATRA) reaction of olefins using bromomalonates as halogen-bonding donors was developed. Using 4-phenylpyridine as the halogen-bonding acceptor, the desired reaction proceeded well under external irradiation of 380 nm light to furnish the corresponding ATRA reaction product. The ATRA reaction was effective in generating the corresponding products for a variety of olefins. Furthermore
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.
Tin-Free Radical Alkoxyamine Addition and Isomerization Reactions by Using the Persistent Radical Effect: Variation of the Alkoxyamine Structure
作者:Kian Molawi、Tobias Schulte、Kai Oliver Siegenthaler、Christian Wetter、Armido Studer
DOI:10.1002/chem.200400936
日期:2005.4.8
Various C-centered radicals can efficiently be generated through thermal C-O-bond homolysis of alkoxyamines. This method is used to perform environmentally benign radical cyclization and intermolecular addition reactions. These alkoxyamine isomerizations and intermolecular carboaminoxylations are mediated by the persistent radicaleffect (PRE). In the paper, the effect of the variation of the alkoxyamine