Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Feb 10;13(5):6349-6358.
doi: 10.1021/acsami.0c21370. Epub 2021 Jan 26.

Pt(II)-Decorated Covalent Organic Framework for Photocatalytic Difluoroalkylation and Oxidative Cyclization Reactions

Zainab Almansaf  1 , Jiyun Hu  1 , Federica Zanca  2 , Hamid R Shahsavari  1   3 , Benjamin Kampmeyer  1 , Miu Tsuji  1 , Kartik Maity  1 , Valerie Lomonte  1 , Yumi Ha  1 , Piero Mastrorilli  4 , Stefano Todisco  4 , Mourad Benamara  5 , Rama Oktavian  2 , Arsalan Mirjafari  6 , Peyman Z Moghadam  2 , Ahmad R Khosropour  1   7 , Hudson Beyzavi  1
Affiliations

Pt(II)-Decorated Covalent Organic Framework for Photocatalytic Difluoroalkylation and Oxidative Cyclization Reactions

Zainab Almansaf et al. ACS Appl Mater Interfaces. .

Abstract

A new covalent organic framework (COF) based on imine bonds was assembled from 2-(4-formylphenyl)-5-formylpyridine and 1,3,6,8-tetrakis(4-aminophenyl)pyrene, which showed an interesting dual-pore structure with high crystallinity. Postmetallation of the COF with Pt occurred selectively at the N donor (imine and pyridyl) in the larger pores. The metallated COF served as an excellent recyclable heterogeneous photocatalyst for decarboxylative difluoroalkylation and oxidative cyclization reactions.

Keywords: covalent organic framework; difluoroalkylation; oxidative cyclization; photocatalysis; platinum; reaction mechanism.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing financial interests.

Figures

Figure 1.
Figure 1.
(A) PXRD pattern of COF-UARK-49-Pt (red line), COF-UARK-49 (blue line), with the simulated patterns for eclipsed (green line) and staggered (gray line) stacking; (B) N2 isotherms at 77K; and (C) Pore size distribution.
Figure 2.
Figure 2.
Comparison of experimental and simulated N2 uptake for COF-UARK-49. N2 favorable adsorption sites at different pressures are shown in the inset. Blue spheres represent N2 molecules. Framework atoms are shown in ball and stick representation.
Figure 3.
Figure 3.
(A–F) Possible coordination modes of Pt in COF-UARK-49-Pt (isomers are not shown).
Figure 4.
Figure 4.
XPS spectra of the N1s binding energy of (A) COF-UARK-49-Pt, (B) COF-UARK-49.
Figure 5.
Figure 5.
Solid-state UV-vis absorption spectra of two linkers, COF-UARK-49 and COF-UARK-49-Pt.
Scheme 1.
Scheme 1.
Synthesis of COF-UARK-49 via imine condensation.
Scheme 2.
Scheme 2.
Substrate scope of decarboxylation-difluoroalkylation.
Scheme 3.
Scheme 3.
Proposed mechanism for the decarboxylation-difluoroalkylation reaction.
Scheme 4.
Scheme 4.
Photo-induced oxidative cyclization reaction catalyzed by COF-UARK-49-Pt.a a A mixture of 4 (0.2 mmol) and 5 (0.1 mmol) in 1 mL DMF were illuminated with a blue LED light for 3 h in the presence of 5 mg (2.3 mol% based on Pt) of the catalyst. Yields were determined by HPLC.
Scheme 5.
Scheme 5.
Proposed mechanism for the photo oxidative cyclization reaction
See this image and copyright information in PMC

References

    1. Marzo L; Pagire SK; Reiser O; König B, Visible-Light Photocatalysis: Does It Make a Difference in Organic Synthesis? Angew. Chem. Int. Ed 2018, 57, 10034–10072. - PubMed
    1. Schultz DM; Yoon TP, Solar Synthesis: Prospects in Visible Light Photocatalysis. Science 2014, 343, 1239176. - PMC - PubMed
    1. Yoon TP; Ischay MA; Du J, Visible Light Photocatalysis as a Greener Approach to Photochemical Synthesis. Nat. Chem 2010, 2, 527–532. - PubMed
    1. Lang X; Chen X; Zhao J, Heterogeneous Visible Light Photocatalysis for Selective Organic Transformations. Chem. Soc. Rev 2014, 43, 473–486. - PubMed
    1. Geng K; He T; Liu R; Tan KT; Li Z; Tao S; Gong Y; Jiang Q; Jiang D, Covalent Organic Frameworks: Design, Synthesis, and Functions. Chem. Rev 2020, 120, 8814–8933. - PubMed