Alternative Palladium-Catalyzed Vinylic C−H Difluoroalkylation of Ketene Dithioacetals Using Bromodifluoroacetate Derivatives
作者:Shuangquan Tian、Xiaoning Song、Dongsheng Zhu、Mang Wang
DOI:10.1002/adsc.201701554
日期:2018.4.3
A palladium‐catalyzedcross‐coupling of α‐oxo ketene dithioacetals and bromodifluoroacetate derivatives has been developed for the synthesis of a class of CF2‐containing tetra‐substituted olefins, which has potential to extend to drug design and material application. The process is proposed to involve two single electron transfer processes accompanied by an alternative loop from palladium(0) to palladium(I)
Ruthenium- and Rhodium-Catalyzed Chemodivergent Couplings of Ketene Dithioacetals and α-Diazo Ketones via C–H Activation/Functionalization
作者:Manman Wang、Lingheng Kong、Qiyue Wu、Xingwei Li
DOI:10.1021/acs.orglett.8b01890
日期:2018.8.3
Chemodivergent coupling of α-acylketene dithioacetals with diazo compounds has been realized under catalyst control. The Ru(II)-catalyzed C–H activation occurred at the olefinic position, and 1:2 coupling with α-diazoketoesters leads to furfurylation. In contrast, the Rh(III)-catalyzed C–H functionalization occurred at both the olefinic and the ortho C(aryl)–H positions, and [4 + 2] annulation afforded
This work describes an electrochemicalammoniumcation enabled hydropyridylation of ketone-activated alkenes under metal- and exogenous reductant free conditions giving access to β-pyridyl ketones, through dual proton-coupled electron transfer and radical cross-coupling. It features a broad substrate scope and allows a gram-scale synthesis. Ammonium chloride plays various roles in this transformation
2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)-Mediated C(<i>sp</i>
<sup>2</sup>
)-C(<i>sp</i>
<sup>3</sup>
) Cross-Dehydrogenative Coupling Reaction: α-Alkylation of Push-Pull Enamines and α-Oxo Ketene Dithioacetals
作者:Dongping Cheng、Lijun Wu、Zhiteng Deng、Xiaoliang Xu、Jizhong Yan
DOI:10.1002/adsc.201700853
日期:2017.12.19
A novel, metal‐free cross‐dehydrogenativecoupling (CDC) reaction of C(sp2)–H bonds of enamines and α‐oxo ketene dithioacetals with C(sp3)–H bonds of 1,3‐diarylpropenes mediated by 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) is reported. The α‐alkylation products are obtained with moderate to good yields. The method provides an efficient and alternative strategy for the synthesis of the corresponding