Redox-Neutral [4 + 2] Annulation of <i>N</i>-Methoxybenzamides with Alkynes Enabled by an Osmium(II)/HOAc Catalytic System
作者:Jian Yang、Liexin Wu、Huiying Xu、Hui Gao、Zhi Zhou、Wei Yi
DOI:10.1021/acs.orglett.9b03827
日期:2019.12.20
C-H activation strategy, an efficient osmium(II)-catalyzed redox-neutral [4 + 2] annulation of N-methoxybenzamides with alkynes has been accomplished. Computational and experimental studies revealed that such transformation leading to the synthesis of the isoquinolone core might follow an Os(II)-Os(IV)-Os(II) catalytic pathway, in which an unusual HOAc-assisted oxidative addition of osmium(II) into
Intermolecular Electrochemical C(<i>sp</i>
<sup>3</sup>
)-H/N-H Cross-coupling of Xanthenes with <i>N</i>
-alkoxyamides: Radical Pathway Mediated by Ferrocene as a Redox Catalyst
with xanthenes is reported. The protocol is carried out in an undivided cell under constant current conditions employing simple, cheap and readily available ferrocene (Fc) as a redox catalyst. Cyclic voltammetry and control experiments disclosed that the dehydrogenative cross‐coupling reaction may proceed via an amidyl radical.
The Rh(III)-catalyzed amidation of C(sp2)-H bonds has been reported by employing the N-methoxyamide as a novel amino source. An excellent level of functional group tolerance can be achieved when N-methoxyamide derivatives are used as the amidating reagents. Importantly, several known bioactive compounds such as Aminalon, Pregabalin, Gabapentin, and Probenecid can be transformed to effective amidating
Rhodium(<scp>iii</scp>)-catalyzed C–H/C–C activation sequence: vinylcyclopropanes as versatile synthons in direct C–H allylation reactions
作者:Jia-Qiang Wu、Zhi-Ping Qiu、Shang-Shi Zhang、Jing-Gong Liu、Ye-Xing Lao、Lian-Quan Gu、Zhi-Shu Huang、Juan Li、Honggen Wang
DOI:10.1039/c4cc07839j
日期:——
Succession of C-Hactivation and C-Cactivation was achieved by using a single rhodium(III) catalyst. Vinylcyclopropanes were used as versatile coupling partners. Mechanistic studies suggest that the olefin insertion step is rate-determining and a facile beta-carbon elimination is involved, which represents a novel ring opening mode of vinylcyclopropanes.
Cp*Co<sup>III</sup>-catalyzed formal [4+2] cycloaddition of benzamides to afford quinazolinone derivatives
作者:Jingshu Yang、Xiao Hu、Zijie Liu、Xueyuan Li、Yi Dong、Gang Liu
DOI:10.1039/c9cc07173c
日期:——
A Cp*CoIII-catalyzed arene C–H bond amidation/annulation of benzamides was developed to afford quinazolinone derivatives in one-pot with high yields and broad substrate scope. This method could be applied to the synthesis of quinazolinone drugs and late-stage modification of natural products.
开发了一种由Cp * Co III催化的苯甲酰胺C / H键酰胺化/环化反应,可一锅制得喹唑啉酮衍生物,并具有高收率和广泛的底物范围。该方法可用于喹唑啉酮类药物的合成和天然产物的后期修饰。