Tetrahedron

Ligand controlled orthogonal base-assisted direct C–H bond arylation in oxa (thia) zole-4-carboxylate series. New insights in nCMD mechanism

L Théveau, O Querolle, G Dupas, C Hoarau

Index: Theveau, Laure; Querolle, Olivier; Dupas, Georges; Hoarau, Christophe Tetrahedron, 2013 , vol. 69, # 22 p. 4375 - 4380

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Citation Number: 13

Abstract

Alkyl-and arylphosphines have been screened in competitive C2–H/C5–H direct phenylation of oxa (thia) zole-4-carboxylates using Cs2CO3 and Rb2CO3 carbonate bases. nCMD-based C2–H selective direct phenylation was highly kinetically reduced (or enhanced) in favor (or to the detriment) of CMD-based direct C5–H phenylation with bromo- and chlorobenzene, respectively, using highly electron-rich ligands. These results gave ...