Selective Synthesis of Dihydrophenanthridine and Phenanthridine Derivatives from the Cascade Reactions of <i>o</i>-Arylanilines with Alkynoates through C–H/N–H/C–C Bond Cleavage
作者:Yuanshuang Xu、Caiyun Yu、Xinying Zhang、Xuesen Fan
DOI:10.1021/acs.joc.1c00256
日期:2021.4.16
unprecedented selective synthesis of dihydrophenanthridine and phenanthridinederivatives through the cascade reactions of 2-arylanilines with alkynoates is presented. Mechanistic studies showed that the formation of the dihydrophenanthridine scaffold involves an initial C(sp2)–H alkenylation of 2-arylaniline with alkynoate followed by an intramolecular aza-Michael addition. When this reaction is carried out
C–H Alkylation of Heteroarenes with Alkyl Oxalates by Molecular Photoelectrocatalysis
作者:Hai-Chao Xu、Fan Xu、Xiao-Li Lai
DOI:10.1055/a-1296-8652
日期:2021.3
An oxidant- and metal-free photoelectrocatalytic C–H alkylation reaction of heteroarenes with alkyloxalates has been developed. Several classes of heteroaromatics, such as quinolines, isoquinolines, pyridines, and phenanthridines, can be alkylated with tertiary or secondary alkyloxalates. The photoelectrochemical synthesis employs 2,4,5,6-tetra-9H-carbazol-9-ylisophthalonitrile as a molecular catalyst
iminyl‐radical formation has been established for the construction of pyridines, quinolines, and phenanthridines from acyl oximes. With fac‐[Ir(ppy)3] as a photoredox catalyst, the acyl oximes were converted by 1 e− reduction into iminyl radical intermediates, which then underwent intramolecular homolytic aromatic substitution (HAS) to give the N‐containing arenes. These reactions proceeded with a broad
已经建立了涉及可见光诱导的亚胺基自由基形成的统一策略,用于从酰基肟中构建吡啶,喹啉和菲啶。用FAC - [的Ir(ppy)3 ]作为催化剂photoredox,酰基肟通过1e中转化-还原成亚氨基自由基中间体,然后行分子内均裂芳族取代(HAS),得到含有N-芳烃其中。这些反应在室温下以宽范围的底物以高收率进行。这种可见光诱导的亚胺基自由基形成策略已成功地应用于五步精简合成苯并[ c ]菲啶生物碱。
Iron-catalysed 1,2-aryl migration of tertiary azides
1,2-Arylmigration of α,α-diaryl tertiary azides was achieved by using the catalytic system of FeCl2/N-heterocyclic carbene (NHC) SIPr·HCl. The reaction generated aniline products in good yields after one-pot reduction of the migration-resultant imines.