Skip to Main content Skip to Navigation
Theses

Stereodivergent and enantioselective total syntheses of chaetominine-type alkaloids and azaphilic radical cascade cyclization for the synthesis of imidazo-fused heteroaromatics and toward analogs of the 2-Carboxyl-6-HydroxyOctahydroIndole (CHOI) Unit

Abstract : Nitrogen-containing compounds have a great interest as this element is found in natural products and drugs, thus the development of efficient methods for their preparation is highly desirable. First, a stereodivergent and enantioselective method has been developed for the total syntheses of chaetominine-type alkaloids including the proposed structures of (-)-pseudofischerine, (-)-aniquinazoline D and (-)-isochaetominine, (-)-isochaetominines A–C, (+)-14-epi-isochaetominine C, as well as the four hitherto unknown stereoisomers of isochaetominine C. The structures of natural (-)-pseudofischerine and (-)-aniquinazoline D have been revised as (-)-isochaetominine C and the structure of the natural (-)-isochaetominine have been revised to (-)-11-epi-chaetominine based on our synthetic efforts. Next, an azaphilic radical cascade cyclization reaction has been developed leading to the efficient synthesis of imidazo-fused heteroaromatics from easily available N-heteroaryl-O-propargyl carbamates. The organocatalyzed electrochemical synthesis has a broad scope, tolerates many common functional groups, and proceeds under mild conditions without the need of transition-metal catalysis or chemical oxidant. Finally, two approaches toward analogs of the CHOI unit have been developed. The key steps of the synthetic route were based on Pd-catalyzed C-allylation and N-allylation, which converted a cyclic bis-allylic substrate into a hexahydroindole scaffold. Depending on the strategy applied, the position of alkene moiety of the resulting hexahydroindole can be obtained at different positions. One-carbon homologation followed by epoxidation or syn-dihydroxylation of the resulting bicyclic intermediates afforded the desired CHOI analogues.
Document type :
Theses
Complete list of metadatas

Cited literature [497 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-01839223
Contributor : Abes Star :  Contact
Submitted on : Saturday, July 14, 2018 - 1:02:18 AM
Last modification on : Sunday, October 25, 2020 - 7:26:30 PM
Long-term archiving on: : Tuesday, October 16, 2018 - 1:46:51 AM

File

2017PA066449.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01839223, version 1

Citation

Zhongyi Mao. Stereodivergent and enantioselective total syntheses of chaetominine-type alkaloids and azaphilic radical cascade cyclization for the synthesis of imidazo-fused heteroaromatics and toward analogs of the 2-Carboxyl-6-HydroxyOctahydroIndole (CHOI) Unit. Organic chemistry. Université Pierre et Marie Curie - Paris VI; Xiamen university (Chine), 2017. English. ⟨NNT : 2017PA066449⟩. ⟨tel-01839223⟩

Share

Metrics

Record views

272

Files downloads

98