Newradical annulation reactions are described involving addition of cyano-substituted alkyl and sulfanyl radicals to aromatic isonitriles. The tandemcyclisation of the resulting imidoyl radicals onto the cyano group affords cyclopenta- and thienoquinoxalines, respectively. The intervention of the isonitriles in the aromatisation process of the cyclohexadienyl radicals is discussed, as well as the
Sulfur-mediated annulation of 1,2-phenylenediamines towards benzofuro- and benzothieno-quinoxalines
作者:Loan T. Tran、Tuan H. Ho、Nhu T. A. Phan、Tung T. Nguyen、Nam T. S. Phan
DOI:10.1039/d0ob00887g
日期:——
Oxidation of sp3 C–H bonds in acetophenones is exploited to annulate with 1,2-phenylenediamines.
在这个句子中,sp3 C-H键的氧化被利用来与1,2-苯二胺进行环化。
An umpolung strategy for rapid access to thermally activated delayed fluorescence (TADF) materials based on phenazine
作者:Huaxing Zhang、Qiang Guo、Hu Cheng、Chunhao Ran、Di Wu、Jingbo Lan
DOI:10.1039/d1cc06705b
日期:——
radical nucleophilic addition/rearrangement of 2-aryl diazaboroles has been accomplished for the first time to construct phenazine structures. This protocol is an umpolung strategy based on the classical electrophilic mechanism, and therefore, a reversed regioselectivity was observed, which provides an opportunity to prepare sterically hindered phenazines. The resulting thermally activated delayed fluorescence
A novel cascade radicalreaction is described involving aryl isothiocyanates and 2-cyanoaryl radicals. The mechanism entails the formation of an alpha-(arylthio)imidoyl radical, a 5-exo-dig cyclization onto a cyano group, and a final 6-membered ring closure of an iminyl radical. The competitive 5-membered spiro-cyclization of the iminyl, leading to an isomeric product, was only observed in the case
DABCO-Catalyzed DMSO-Promoted Sulfurative 1,2-Diamination of Phenylacetylenes with Elemental Sulfur and <i>o</i>-Phenylenediamines: Access to Quinoxaline-2-thiones
The oxidative amination of alkynes typically requires transition metal catalysts and strong oxidants. Herein, we alternatively utilize DABCO as a sulfur-activating catalyst to achieve the sulfurative 1,2-diamination of phenylacetylenes with elemental sulfur and o-phenylenediamines. DMSO was found to be particularly suitable for use as a terminaloxidant for this three-component process. A mechanistic