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
. 2022 Aug 18;3(3):101618.
doi: 10.1016/j.xpro.2022.101618. eCollection 2022 Sep 16.

A ligand-enabled metallaphotoredox protocol for Suzuki-Miyaura cross-couplings for the synthesis of diarylmethanes

Jianbin Li  1 , Chia-Yu Huang  1 , Chao-Jun Li  2
Affiliations

A ligand-enabled metallaphotoredox protocol for Suzuki-Miyaura cross-couplings for the synthesis of diarylmethanes

Jianbin Li et al. STAR Protoc. .

Abstract

Here, we present a ligand-enabled metallaphotoredox Suzuki-Miyaura cross-coupling protocol for the facile synthesis of diarylmethanes. Specifically, we describe the preparation of a unique class of ligands, 2,4-diarylquinolines, and demonstrate their application in nickel-catalyzed fragment couplings between alkyltrifluoroborates and haloarenes. We detail the synthesis of the most enabling ligand, PPQN2,4-di-OMe, on a gram scale via sequential Grignard reaction and Friedländer condensation. We also outline how coupling reactions are performed without external photocatalysts under violet light irradiation. For complete details on the use and execution of this protocol, please refer to Li et al. (2022b).

Keywords: Chemistry; Energy.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing interests.

Figures

None
Graphical abstract
Figure 1
Figure 1
Solvent degassing setup
Figure 2
Figure 2
Overview of the photochemical setup (i) Microwave reaction tube, rubber septum, and Teflon-coated magnetic stirring bar. (ii) 390 nm PR160L Kessil lamp (5 cm away from the reaction tube). (iii) Clamp stand and stirring hot plate. (iv) Cooling pad for temperature maintenance. (v) Clamp.
Scheme 1
Scheme 1
Diphenylmethane(2-aminophenyl)(4-methoxyphenyl)methanone (3)
Scheme 2
Scheme 2
Synthesis of PPQN2,4-di-OMe ligand.
Scheme 3
Scheme 3
Synthesis of diphenylmethane (8)
Figure 3
Figure 3
Freezing the reaction mixture in liquid nitrogen
Figure 4
Figure 4
Filtration with a silica pad
Figure 5
Figure 5
Purification of the product-containing silica gel
See this image and copyright information in PMC

References

    1. Chan A.Y., Perry I.B., Bissonnette N.B., Buksh B.F., Edwards G.A., Frye L.I., Garry O.L., Lavagnino M.N., Li B.X., Liang Y., et al. Metallaphotoredox: the merger of photoredox and transition metal catalysis. Chem. Rev. 2022;122:1485–1542. - PubMed
    1. Chen C., Peters J.C., Fu G.C. Photoinduced copper-catalysed asymmetric amidation via ligand cooperativity. Nature. 2021;596:250–256. - PMC - PubMed
    1. Gandeepan P., Koeller J., Korvorapun K., Mohr J., Ackermann L. Visible-light-enabled ruthenium-catalyzed meta-C-H alkylation at room temperature. Angew. Chem. Int. Ed. Engl. 2019;58:9820–9825. - PubMed
    1. Huang C.-Y., Li J., Li C.-J. Photocatalytic C(sp3) radical generation via C-H, C-C, and C-X bond cleavage. Chem. Sci. 2022;13:5465–5504. - PMC - PubMed
    1. Kobayashi K., Fujita S., Fukamachi S., Konishi H. One-pot synthesis of quinoline-2(1H)-thiones from 2-isocyanostyrenes via electrocyclic reaction of the corresponding 2-isothiocyanatestyrenes. Synthesis. 2009;2009:3378–3382.

Publication types

LinkOut - more resources