Photoarylation of Pyridines Using Aryldiazonium Salts and Visible Light: An EDA Approach

Author(s)

Bartolomeu, Aloisio de A. ^{[1, 2]} ; Silva, Rodrigo C. ^[1] ; Brocksom, Timothy J. ^[1] ; Noel, Timothy ^[2] ; de Oliveira, Kleber T. ^[1]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Quim, BR-13565905 Sao Carlos, SP - Brazil

^[2] Eindhoven Univ Technol, Dept Chem Engn & Chem, Sustainable Proc Engn, Micro Flow Chem & Synthet Methodol, De Rondom 70, STO 1-37, NL-5612 AP Eindhoven - Netherlands

• Document type: Journal article
• Source: Journal of Organic Chemistry; v. 84, n. 16, p. 10459-10471, AUG 16 2019.
• Web of Science Citations: 1

Abstract

A metal-free methodology for the photoarylation of pyridines, in water, is described giving 2 and 4-arylated-pyridines in yields up to 96%. The scope of the aryldiazonium salts is presented showing important results depending on the nature and position of the substituent group in the diazonium salt, that is, electron-donating or electron-withdrawing in the ortho, meta, or para positions. Further heteroaromatics were also successfully photoarylated. Mechanistic studies and comparison between our methodology and similar metal-catalyzed procedures are presented, suggesting the occurrence of a visible-light EDA complex which generates the aryl radical with no need for an additional photocatalyst. (AU)

• FAPESP's process: 13/07276-1 - CEPOF - Optics and Photonic Research Center
• Grantee: Vanderlei Salvador Bagnato
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 18/00106-7 - Photocatalyzed Reactions by using porphyrins and continuous flow conditions: Arylations of heterocycles and activated olefins.
• Grantee: Kleber Thiago de Oliveira
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/24506-3 - Synthesis of high conjugated phthalocyanine and porphyrin derivatives: strategies using RMCs and Diels-Alder reactions
• Grantee: Aloisio de Andrade Bartolomeu
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 18/08772-6 - Direct C-H photocatalyzed arylation of quinolines, pyridines and styrenes with aryldiazonium and diaryliodonium salts
• Grantee: Aloisio de Andrade Bartolomeu
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 18/00879-6 - Arylation reactions of heterocycles photocatalysed by porphyrins in both batch and continuous flow conditions.
• Grantee: Rodrigo Costa e Silva
• Support Opportunities: Scholarships in Brazil - Doctorate