Palladium-Catalyzed Oxidative Insertion of Carbon Monoxide to N-Sulfonyl-2-aminobiaryls through C–H Bond Activation: Access to Bioactive Phenanthridinone Derivatives in One Pot
摘要:
Palladium-catalyzed oxidative carbonylation of N-sulfonyl-2-aminobiaryls through C-H bond activation and C-C, C-N bond formation under TFA-free and milder conditions has been developed. The reaction tolerates a variety of substrates and provides biologically important phenanthrldlnone derivatives in yields up to 94%.
Palladium-Catalyzed C–H Bond Activation by Using Iminoquinone as a Directing Group and an Internal Oxidant or a Co-oxidant: Production of Dihydrophenanthridines, Phenanthridines, and Carbazoles
A palladium-catalyzedC–Hbondactivation reaction, via a redox-neutral pathway, for the preparation of dihydrophenanthridine, phenanthridine, and carbazole derivatives from biaryl 2-iminoquinones is developed. The preinstalled iminoquinone was designed to act as a directing group for ortho C–Hactivation and an internal oxidant or a co-oxidant. This catalysis proceeded through the following sequence:
2-(naphthalen-1-yl)anilines and p-benzoquinones through copper (II)-mediated radicalcyclisation. This unusual cyclisationreaction resulted in the robust and efficient syntheses of iptycenes with an acridinone motif. These iptycenes can be further transformed to planar acridinone heterocyclics through the Diels–Alder reaction.
novel, simple, and efficient approach for the synthesis of benzofulvene derivatives from o‐arylaniline substrates through C−H bond activation with two diarylacetylenes as an implicit benzofulvene unit. The reactivity of synthesized benzofulvenes toward oxidation was investigated, and they were shown to transform into phenanthridines, oxabenzofulvenes, and fluorescent polycyclics.
Palladium-Catalyzed Directed Atroposelective C–H Allylation via β-H Elimination: 1,1-Disubstituted Alkenes as Allyl Surrogates
作者:Bei-Bei Zhan、Zhen-Sheng Jia、Jun Luo、Liang Jin、Xu-Feng Lin、Bing-Feng Shi
DOI:10.1021/acs.orglett.0c03757
日期:2020.12.18
C–H allylation with 1,1-disubstituted alkenes via β-H elimination remains challenging, because of the low reactivity and difficulty of controlling selectivity. Herein, the development of a Pd(II)-catalyzed directed atroposelective C–H allylation with methacrylates is described. Exclusive allylic selectivity was achieved. A vast array of axially chiral biaryl-2-amines are efficiently synthesized with
TfOH-promoted Classical Nazarov-type Cyclization of Benzofulvenes: Synthesis of Polycyclic 5<i>H</i>,10′<i>H</i>-spiro[benzo[<i>k</i>]phenanthridine-5,6′-dibenzopentalenes]
The reaction of o-benzofulvene with TfOH leads to intramolecular cyclization through novel C–C and C–N bond formation, resulting in the formation of 5H,10′H-spiro[benzo[k]phenanthridine-5,6′-dibenzopentalene]. This protocol provides a new molecular framework with reasonable to excellent yields and tolerates various electron-withdrawing/donating substituents. This method yields diastereoselectivity