Volume 62, Issue 36 e202304699
Research Article

Cl2 Mediates Direct and Selective Conversion of Inert C(sp3)−H Bonds into Aldehydes/Ketones

Dr. Qinhua Zhang

Dr. Qinhua Zhang

State Key Laboratory of Heavy Oil Processing, Institute of New Energy, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580 P. R. China

Contribution: Data curation (lead), ​Investigation (lead), Methodology (lead), Software (lead), Writing - original draft (lead)

Search for more papers by this author
Dr. Bo An

Dr. Bo An

State Key Laboratory of Heavy Oil Processing, Institute of New Energy, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580 P. R. China

Contribution: Data curation (supporting), Software (supporting)

Search for more papers by this author
Dr. Yu Lei

Dr. Yu Lei

Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275 China

Contribution: Data curation (supporting), ​Investigation (supporting)

Search for more papers by this author
Zhixiao Gao

Zhixiao Gao

State Key Laboratory of Heavy Oil Processing, Institute of New Energy, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580 P. R. China

Contribution: Resources (supporting), Software (supporting)

Search for more papers by this author
Dr. Haonan Zhang

Dr. Haonan Zhang

State Key Laboratory of Heavy Oil Processing, Institute of New Energy, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580 P. R. China

Contribution: Data curation (supporting), Validation (supporting)

Search for more papers by this author
Prof. Sheng Xue

Prof. Sheng Xue

Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, 266021 P. R. China

Contribution: Conceptualization (supporting), Resources (supporting)

Search for more papers by this author
Prof. Xin Jin

Prof. Xin Jin

State Key Laboratory of Heavy Oil Processing, Institute of New Energy, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580 P. R. China

Contribution: Formal analysis (supporting), Resources (supporting)

Search for more papers by this author
Prof. Wengang Xu

Prof. Wengang Xu

State Key Laboratory of Heavy Oil Processing, Institute of New Energy, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580 P. R. China

Contribution: ​Investigation (supporting), Methodology (supporting)

Search for more papers by this author
Zihan Wu

Zihan Wu

State Key Laboratory of Heavy Oil Processing, Institute of New Energy, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580 P. R. China

Contribution: Data curation (supporting)

Search for more papers by this author
Prof. Mingbo Wu

Corresponding Author

Prof. Mingbo Wu

State Key Laboratory of Heavy Oil Processing, Institute of New Energy, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580 P. R. China

Contribution: Funding acquisition (lead), Project administration (lead), Supervision (lead), Writing - review & editing (lead)

Search for more papers by this author
Prof. Xin Yang

Corresponding Author

Prof. Xin Yang

Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275 China

Contribution: ​Investigation (equal), Methodology (equal), Writing - review & editing (equal)

Search for more papers by this author
Prof. Wenting Wu

Corresponding Author

Prof. Wenting Wu

State Key Laboratory of Heavy Oil Processing, Institute of New Energy, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580 P. R. China

Contribution: Formal analysis (lead), Project administration (lead), Supervision (lead), Writing - review & editing (lead)

Search for more papers by this author
First published: 06 July 2023
Citations: 5

Graphical Abstract

A thiophene-based covalent triazine polymer facilitates effective conversion of O2→H2O2→⋅OH→Cl⋅→Cl2.− in the aqueous phase. Cl2.−, with a longer lifetime, transfers into organic phase and activates C(sp3)−H bonds to generate unstable dichlorinated intermediates by successive hydrogen abstraction and chlorination. These unstable intermediates hydrolyze into either aldehydes or ketones with higher selectivity than that of benzyl dichloride.

Abstract

Developing new reactive pathway to activate inert C(sp3)−H bonds for valuable oxygenated products remains a challenge. We prepared a series of triazine conjugated organic polymers to photoactivate C−H into aldehyde/ketone via O2→H2O2→⋅OH→Cl⋅→Cl2. Experiment results showed Cl2 could successively activate C(sp3)−H more effectively than Cl⋅ to generate unstable dichlorinated intermediates, increasing the kinetic rate ratio of dichlorination to monochlorination by a factor of 2,000 and thus breaking traditional dichlorination kinetic constraints. These active intermediates were hydrolyzed into aldehydes or ketones easily, when compared with typical stable dichlorinated complexes, avoiding chlorinated by-product generation. Moreover, an integrated two-phase system in an acid solution strengthened the Cl2 mediated process and inhibited product overoxidation, where the conversion rate of toluene reached 16.94 mmol/g/h and the selectivity of benzaldehyde was 99.5 %. This work presents a facile and efficient approach for selective conversion of inert C(sp3)−H bonds using Cl2.

Conflict of interest

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available in the supplementary material of this article.

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.