Visible-light-driven spirocyclization of epoxides via dual titanocene and photoredox catalysis

Autor:	Shuangjie Lin, Fusheng Li, Caizhe Shi, Yuqing Chen, Lei Shi
Rok vydání:	2020
Předmět:	Chemistry chemistry.chemical_compound Fluorophore Photocatalysis Photoredox catalysis Reactivity (chemistry) Electron donor General Chemistry Cyclic voltammetry Photochemistry Stereocenter Catalysis
Zdroj:	Chemical Science
ISSN:	2041-6539 2041-6520
DOI:	10.1039/c9sc05601g
Popis:	We describe the synergistic utilization of titanocene/photoredox dual catalysis driven by visible light for the radical opening/spirocyclization of easily accessible epoxyalkynes. This environmentally benign process uses the organic donor–acceptor fluorophore 2,4,5,6-tetra(9H-carbazol-9-yl)isophthalonitrile (4CzIPN) as a photocatalyst and Hantzsch ester (HE) as an electron donor instead of stoichiometric metallic reductants. The photocatalytic conditions showed exceptionally high reactivity for the synthesis of privileged and synthetically challenging spirocycles featuring a spiro all-carbon quaternary stereocenter. Cyclic voltammetry (CV) studies suggest that Cp2TiIIICl is the catalytically active species. We describe the synergistic utilization of titanocene/photoredox dual catalysis driven by visible light for radical opening/spirocyclization of easily accessible epoxyalkynes.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ecd29a6e2f13f227b4882690e2f15459 https://doi.org/10.1039/c9sc05601g Zobrazit plný text záznamu