Visible-Light-Driven Bisfunctionalization of Unactivated Olefins via the Merger of Proton-Coupled Electron Transfer and Carbene Catalysis

2021 ◽  
Author(s):  
Bei Zhang ◽  
Jian-Qing Qi ◽  
Yuhan Liu ◽  
Zhipeng Li ◽  
Jian Wang
Keyword(s):  
Electron Transfer ◽  
Visible Light ◽  
Proton Coupled Electron Transfer ◽  
Visible Light Driven

scholarly journals Light-Driven Depolymerization of Native Lignin Enabled by Proton- Coupled Electron Transfer

2019 ◽  
Author(s):  
Suong Nguyen ◽  
Phillip Murray ◽  
Robert Knowles
Keyword(s):  
Electron Transfer ◽  
Visible Light ◽  
Bond Cleavage ◽  
Direct Conversion ◽  
Alkoxy Radical ◽  
Radical Intermediate ◽  
Polymer Backbone ◽  
Good Efficiency ◽  
Chemical Reagents ◽  
Proton Coupled Electron Transfer

<div><p>Here we report a catalytic, light-driven method for the redox-neutral depolymerization of native lignin biomass at ambient temperature. This transformation proceeds via a proton-coupled electron-transfer (PCET) activation of an alcohol O–H bond to generate a key alkoxy radical intermediate, which then drives the <i>β</i>-scission of a vicinal C–C bond. Notably, this depolymerization is driven solely by visible light irradiation, requiring no stoichiometric chemical reagents and producing no stoichiometric waste. This method exhibits good efficiency and excellent selectivity for the activation and fragmentation of <i>β</i>-O-4 linkages in the polymer backbone, even in the presence of numerous other PCET-active functional groups. DFT analysis suggests that the key C–C bond cleavage reactions produce non-equilibrium product distributions, driven by excited-state redox events. These results provide further evidence that visible-light photocatalysis can serve as a viable method for the direct conversion of lignin biomass into valuable arene feedstocks.</p></div>

Asymmetric alkylation of remote C(sp3)–H bonds by combining proton-coupled electron transfer with chiral Lewis acid catalysis

2017 ◽  
Vol 53 (64) ◽  
pp. 8964-8967 ◽  
Author(s):  
Wei Yuan ◽  
Zijun Zhou ◽  
Lei Gong ◽  
Eric Meggers
Keyword(s):  
Electron Transfer ◽  
Hydrogen Atom ◽  
Visible Light ◽  
Lewis Acid ◽  
Acid Catalysis ◽  
Hydrogen Atom Transfer ◽  
Lewis Acid Catalysis ◽  
Asymmetric Alkylation ◽  
Proton Coupled Electron Transfer ◽  
Chiral Lewis Acid

The catalytic asymmetric alkylation of the remote, unactivated δ-position of N-alkyl amides was enabled by the combination of visible-light-induced proton-coupled electron transfer, 1,5-hydrogen atom transfer, and chiral Lewis acid catalysis.

Super-paramagnetic nano-Fe3O4/graphene for visible-light-driven hydrogen evolution

2015 ◽  
Vol 51 (50) ◽  
pp. 10158-10161 ◽  
Author(s):  
Wenyan Zhang ◽  
Chao Kong ◽  
Gongxuan Lu
Keyword(s):  
Electron Transfer ◽  
Visible Light ◽  
High Activity ◽  
Hydrogen Evolution ◽  
Catalytic Performance ◽  
Visible Light Driven ◽  
Repair Ability ◽  
Nano Fe3o4 ◽  
Surface Repair

In this work, a super-paramagnetic nano-architecture, which could be separated and re-dispersed easily for reuse, was designed for effective visible-light-driven H2 evolution. The photo-catalytic performance was remarkably enhanced by the electron-transfer and surface-repair ability of graphene, and the high activity of the exposed Pt(111) facet.

Sign in / Sign up

Export Citation Format

Share Document