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Published on: May 21, 2019
Direct C7-H Arylation of Pyrazolo[1,5-a]azines with Aryl Chlorides
1Medicinal Chemistry, Research and Early Development, Respiratory and Immunology, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden.
Abstract:
C7-Arylated pyrazolo[1,5-a]azines are important structural motifs with profound applications in drug and material research. Here, we report a general and straighforward synthesis of these bi(hetero)aryls via palladium-catalyzed direct C-H arylation, employing low-cost and abundant (hetero)aryl chlorides as the aryl source. The catalytic system is robust and covers a wide substrate scope regarding heteroarenes as well as (hetero)aryl chlorides, with possible extension to the C-H arylation of [1,2,4]triazolo[1,5-a]pyrimidines. This study also presents a rare example of using (hetero)aryl chlorides for the direct C-H arylation of six-membered heteroarenes.
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