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
Rh(<scp>iii</scp>)-catalyzed diastereoselective cascade annulation of enone-tethered cyclohexadienones <i>via</i> C(sp<sup>2</sup>)–H bond activation
作者:Sandip B. Jadhav、Sundaram Maurya、N. Navaneetha、Rambabu Chegondi
DOI:10.1039/d1cc05941f
日期:——
highly diastereoselective arylative cyclization of enone-tethered cyclohexadienones via Rh(III)-catalyzed C–H activation of N-methoxybenzamides. This reaction proceeds through the formation of a five-membered rhodacycle followed by bis-Michael cascade annulation to access functionalized bicyclic scaffolds with four contiguous stereocenters with a broad substrate scope. These products have excellent functional
在此,我们报告了通过Rh( III ) 催化的N-甲氧基苯甲酰胺的C-H 活化对烯酮系环己二烯酮进行高度非对映选择性芳基化环化。该反应通过形成五元罗丹环进行,然后是双迈克尔级联环化,以访问具有广泛底物范围的具有四个连续立体中心的功能化双环支架。这些产品具有出色的功能手柄,允许进一步合成转化以增加结构复杂性。此外,还介绍了芳基化环化的机理研究和克级实验。
Pd(II)-Catalyzed Annulation Reactions of Epoxides with Benzamides to Synthesize Isoquinolones
作者:Huihong Wang、Fei Cao、Weiwei Gao、Xiaodong Wang、Yuhang Yang、Tao Shi、Zhen Wang
DOI:10.1021/acs.orglett.0c04097
日期:2021.2.5
Epoxides as alkylating reagents are unprecedentedly applied in Pd(II)-catalyzed C–H alkylation and oxidative annulation of substituted benzamides to synthesize isoquinolones rather than isochromans, which is accomplished through alerting the previously reported reaction mechanism by the addition of oxidant and TEA. Under these conditions, various isoquinolones have been prepared with yields up to 92%
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.
α-MsO/TsO/Cl Ketones as Oxidized Alkyne Equivalents: Redox-Neutral Rhodium(III)-Catalyzed CH Activation for the Synthesis of N-Heterocycles
作者:Da-Gang Yu、Francisco de Azambuja、Frank Glorius
DOI:10.1002/anie.201310272
日期:2014.3.3
α‐Halo and pseudohalo ketones are used for the first time as C(sp3)‐based electrophiles in transition‐metal‐catalyzed CHactivation and as oxidizedalkyneequivalents in RhIII‐catalyzed redox‐neutral annulations to generate diverse N‐heterocycles. This transformation is efficient and scalable. Due to the mild reaction conditions, a variety of functional groups could be tolerated.