Cooperative Interplay of Brønsted Acid and Lewis Acid Sites in MIL-101(Cr) for Cross-Dehydrogenative Coupling of C-H Bonds

Jingwen Chen; Yuanyuan Zhang; Xiaoling Chen; Siyun Dai; Zongbi Bao; Qiwei Yang; Qilong Ren; Zhiguo Zhang

doi:10.1021/acsami.0c20369

Cooperative Interplay of Brønsted Acid and Lewis Acid Sites in MIL-101(Cr) for Cross-Dehydrogenative Coupling of C-H Bonds

ACS Appl Mater Interfaces. 2021 Mar 10;13(9):10845-10854. doi: 10.1021/acsami.0c20369. Epub 2021 Mar 2.

Authors

Jingwen Chen^{1

2}, Yuanyuan Zhang^{1

2}, Xiaoling Chen¹, Siyun Dai¹, Zongbi Bao^{1

2}, Qiwei Yang^{1

2}, Qilong Ren^{1

2}, Zhiguo Zhang^{1

2}

Affiliations

¹ Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, P. R. China.
² Institute of Zhejiang University-Quzhou, Quzhou 324000, P. R.China.

PMID: 33648335
DOI: 10.1021/acsami.0c20369

Abstract

Cross-dehydrogenative coupling (CDC) is an effective tool for carbon-carbon bond formation in chemical synthesis. Herein, we report a metal-organic framework (MOF) possessing dual Lewis acidic Cr sites and sulfonic acid sites (MIL-101(Cr)-SO₃H) as an efficient catalytic material for direct cross-coupling of xanthene and different nucleophiles using O₂ as the oxidant. The highly porous structure of MIL-101(Cr)-SO₃H enables the free access of reactants to the catalytic active sites inside MOF pores. Kinetic studies indicated that the Cr sites of MOF accelerate the rate-limiting autoxidation reaction of xanthene, which synergistically work with the sulfonic acid group on MOF ligands in promoting the CDC reactions. Besides, the catalytic system shows excellent functional group compatibility, and a variety of valuable xanthene derivatives were synthesized with satisfactory yields. Furthermore, MIL-101(Cr)-SO₃H can be reused and its catalytic activity and crystal structure remain after six consecutive runs.

Keywords: C−H activation; cross-dehydrogenative coupling; metal−organic framework; oxygen; sulfonic acid; xanthene.