Regioselective Metalation and Functionalization of the Pyrazolo[1,5-a]pyridine Scaffold Using Mg- and Zn-TMP Bases

Balkenhohl, Moritz; Salgues, Bruno; Hirai, Takahiro; Karaghiosoff, Konstantin and Knochel, Paul (2018): Regioselective Metalation and Functionalization of the Pyrazolo[1,5-a]pyridine Scaffold Using Mg- and Zn-TMP Bases. In: Organic Letters, Vol. 20, No. 10: pp. 3114-3118

Abstract

A regioselective functionalization of the pyrazolo[1,5-a]pyridine scaffold using Mg- and Zn-TMP bases (TMP = 2,2,6,6-tetramethylpiperidyl) in the presence or absence of BF3 center dot OEt2 is described. Also, various functionalized pyrazolo[1,5-a]pyridines bearing an ester function (and an NHBoc or ethyl group) are magnesiated and functionalized, leading to polysubstituted heterocycles. Additionally, a sulfoxide directed ortho-metalation, followed by the transition-metal-free amination of a pyrazolo[1,5-a]pyridine sulfoxide, using a magnesium amide, is reported.

• Item Type: Journal article
• Faculties: Chemistry and Pharmacy > Department of Chemistry
• Subjects: 500 Science > 540 Chemistry
• ISSN: 1523-7060
• Language: English