Charting the Chemical Reactivity Space of 2,3-Substituted Furo[2,3-b]pyridines Synthesized via the Heterocyclization of Pyridine-N-oxide Derivatives

Author(s)

Fumagalli, Fernando ; Emery, Flavio da Silva

• Document type: Journal article
• Source: Journal of Organic Chemistry; v. 81, n. 21, p. 10339-10347, NOV 4 2016.
• Web of Science Citations: 10

Abstract

A concise strategy for the synthesis of 2,3 substituted furo{[}2,3-b]pyridines is described. Mild, metal-free conditions were successfully applied to produce a range of 2 (alkyl or aryl)-3-ethylcarboxylate-furo{[}2,3-b]pyriclies in yields of 50-91%. Then, the chemical reactivity of this heterocyclic framework was explored to develop straightforward methods for its functionalization. The pyridine moiety reactivity was successfully explored by C-H amination and borylation reactions, although C-H fluorination and radical C-H arylation processes were not as efficient. In addition, while the furopyridine core proved stable under basic conditions, the ring-opening reaction of the furan moiety with hydrazine generated a valuable new pyridine-dihydropyrazolone scaffold. (AU)

• FAPESP's process: 15/06588-5 - Development of library of heterocyclic fragments based on new heteroaromatic cores
• Grantee: Fernando Fumagalli
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 14/50265-3 - Distribution and metabolism of natural and synthetic xenobiotics: from the comprehension of reactional process to tissue imaging generation
• Grantee: Norberto Peporine Lopes
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants