This article is cited in 3 papers

Communications

Regioselectivity of the Chan–Lam coupling of ambident nitropyrazoles with trans-styrylboronic acid

D. V. Davydov, P. K. Sazonov, Yu. F. Oprunenko

Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow, Russian Federation

Abstract: Regioselectivity of the Chan–Lam coupling of ambident nitropyrazoles with trans-styrylboronic acid depends on the base and catalyst nature and can vary the N(1)/N(2)-isomer ratio from ∼2 : 1 to ∼1 : 2. 2-Methyl-4-nitro- and 2,4-dinitroimidazoles are unreactive in this reaction. The structure of N(1)/N(2) isomers was elucidated by NOE measurements and by the comparison of experimental and DFT calculated ¹³C NMR chemical shifts.

Keywords: pyrazoles, nitropyrazoles, vinylpyrazoles, vinylboronic acids, Chan–Lam reaction, copper catalysis, ¹³C NMR, DFT.

Language: English

DOI: 10.1016/j.mencom.2020.03.018

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