Ligandless Palladium-Catalyzed Regioselective Direct C-H Arylation of Imidazo[1,2-a]imidazole Derivatives.

Sandrine Grosse (1) , Christelle Pillard (2) , Stéphane Massip (3) , Mathieu Marchivie (4) , Christian Jarry (3) , Philippe Bernard (2) , Gérald Guillaumet (1)

1 ICOA - Institut de Chimie Organique et Analytique
2 Greenpharma S.A.S.
3 IECB - Institut Européen de Chimie et Biologie
4 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Herein a novel access to functionalizable 6-substituted imidazo[1,2-a]imidazole scaffolds is described. The reactivity of this heterobicyclic unit toward direct C-H arylation was studied, and conditions allowing regioselective arylation at position 3 were successfully developed. The practicability of this method is manifested by the ligandless conditions and low catalyst loading. The strategy is functional group tolerant and provides rapid access to a large variety of 3,6-di(hetero)arylated imidazo[1,2-a]imidazole derivatives. A second arylation at position 2 was then carried out, and a library of diversified 2,3,6-tri(hetero)arylated imidazo[1,2-a]imidazoles was generated in good yields. A one-pot, two-step procedure was finally developed.

Domaines: Matériaux

Sandrine Grosse, Christelle Pillard, Stéphane Massip, Mathieu Marchivie, Christian Jarry, et al.. Ligandless Palladium-Catalyzed Regioselective Direct C-H Arylation of Imidazo[1,2-a]imidazole Derivatives.. Journal of Organic Chemistry, 2015, 80 (17), pp.8539-8551. ⟨10.1021/acs.joc.5b00534⟩. ⟨hal-01204848⟩