photocatalytic aerobicoxidative lactonization of arene C(sp2)–H bonds proceeds in the presence of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and tert-butyl nitrite (TBN). Under the optimized conditions, a range of 2-arylbenzoic acids is converted into the corresponding benzocoumarin derivatives in moderate to excellent yields. This method is characterized by its atom economy, mild reaction conditions, the
Intramolecular Aromatic C–H Acyloxylation Enabled by Iron Photocatalysis
作者:Siqi Xia、Kunjun Hu、Chuanhu Lei、Jian Jin
DOI:10.1021/acs.orglett.0c00002
日期:2020.2.21
protocol for the intramolecular aromatic C-H oxygenation of 2-biphenylcarboxylic acids has been achieved via iron photocatalysis. The 2-biphenylcarboxylic acids with a diverse array of substituents at both phenyl rings could furnish the oxygenation products in good to excellent yields. We speculate that the aryl carboxylate-iron(III) complexes should generate the aroyloxy radicals and iron(II) upon visible
Herein we described an access to biaryl lactones from ortho-aryl benzoicacids via intramolecular O–H/C–H oxidative coupling with the commonly used ceriumammoniumnitrate (CAN) as the one-electron oxidant under a thermal condition. The radical interrupting experiment suggested a radical process, while the kinetic isotope effect (KIE) showed that the C–H cleavage likely was not involved in the rate-determining
KO<sup>t</sup>Bu mediated efficient approach for the synthesis of fused heterocycles via intramolecular O-/N-arylations
作者:Raju Singha、Atiur Ahmed、Yasin Nuree、Munmun Ghosh、Jayanta K. Ray
DOI:10.1039/c5ra07532g
日期:——
KOtBu mediated an efficient methodology has been developed for the synthesis of 6H-benzo[c]chromenes, 6H-benzo[c]chromen-6-ones, carbazoles, dibenzofurans and dibenzooxepins.