A Novel Approach to the Practical Synthesis of Sulfides: An InBr<sub>3</sub>-Et<sub>3</sub>SiH Catalytic System Promoted the Direct Reductive Sulfidation of Acetals with Disulfides
Anodic Cleavage of Several Ketone <i>N</i>-Phenylsemicarbazones into Methyl <i>N</i>-Phenylcarbamate and the Corresponding Dimethyl Acetals
作者:Shinnosuke Nishikawa、Haruki Yamamori、Kousuke Ohashi、Mitsuhiro Okimoto、Masayuki Hoshi、Takashi Yoshida
DOI:10.1080/00397911.2012.667184
日期:2013.7.3
Abstract Several ketone N-phenylsemicarbazones were electrooxidized in the presence of potassium iodide and a base using methanol as the solvent to give nearly commensurate amounts of methyl N-phenylcarbamate and the corresponding dimethyl acetals. Continuous evolution of gaseous nitrogen was observed from the anolyte during the electrooxidation. The reactions were carried out under very mild reaction
Coupling Reaction of Enol Derivatives with Silyl Ketene Acetals Catalyzed by Gallium Trihalides
作者:Yoshihiro Nishimoto、Yuji Kita、Hiroki Ueda、Hiroto Imaoka、Kouji Chiba、Makoto Yasuda、Akio Baba
DOI:10.1002/chem.201602150
日期:2016.8.8
cross‐coupling reaction between enolderivatives and silyl ketene acetals catalyzed by GaBr3 took place to give the corresponding α‐alkenyl esters. GaBr3 showed the most effective catalytic ability, whereas other metal salts such as BF3⋅OEt2, AlCl3, PdCl2, and lanthanide triflates were not effective. Various types of enol ethers and vinyl carboxylates as enolderivatives are amenable to this coupling
A highly efficient metal-free aldol-type reaction of various acetals or ketals with fluorinated silylenolethers catalysed by less than 1 mol% HClO4 (70 wt%, aq.) is developed. This provides expedient access to a wide array of valuable fluoroalkyl ethers featuring a ketone carbonyl functionality in good to excellent yields (40 examples). Furthermore, the thus obtained adducts are readily elaborated
Development and Mechanistic Studies of the Iridium‐Catalyzed C−H Alkenylation of Enamides with Vinyl Acetates: A Versatile Approach for Ketone Functionalization
作者:Bo Zhou、Xiaotian Qi、Peng Liu、Guangbin Dong
DOI:10.1002/anie.202107331
日期:2021.9.13
Ketone functionalization is a cornerstone of organic synthesis. Herein, we describe the development of an intermolecular C−H alkenylation of enamides with the feedstock chemical vinyl acetate to access diverse functionalized ketones. Enamides derived from various cyclic and acyclic ketones reacted efficiently, and a number of sensitive functional groups were tolerated. In this iridium-catalyzed transformation