Conditions for palladium-catalyzed direct arylations of 4-bromo and 4-iodo N-substituted pyrazoles without C-Br or C-I bond cleavage - Université de Rennes Access content directly
Journal Articles Organic Chemistry Frontiers Year : 2015

Conditions for palladium-catalyzed direct arylations of 4-bromo and 4-iodo N-substituted pyrazoles without C-Br or C-I bond cleavage

Abstract

The Pd-catalyzed arylation at the C5 position of N-protected pyrazole derivs. bearing bromo or iodo substituents at the C4 position is described. A simple phosphine-free catalytic system was used, namely, 1 mol% Pd(OAc)2 in DMA in the presence of KOAc as the base. A wide aryl bromide scope as a coupling partner has been coupled with pyrazole derivs. The reaction was very chemoselective as the C-halogen bonds of the pyrazole units were not involved in the C-H bond arylation process. Some examples demonstrating the synthetic potential of the bromo and iodo pyrazole substituents for chem. transformations are reported.
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hal-01162340 , version 1 (10-06-2015)

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Mariem Brahim, Imen Smari, Hamed Ben Ammar, Bechir Ben Hassine, Jean-François Soulé, et al.. Conditions for palladium-catalyzed direct arylations of 4-bromo and 4-iodo N-substituted pyrazoles without C-Br or C-I bond cleavage. Organic Chemistry Frontiers, 2015, 2 (8), pp.917-926. ⟨10.1039/c5qo00093a⟩. ⟨hal-01162340⟩
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