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Ag(I)-C-H Activation Enables Near-Room-Temperature Direct ?-Arylation of Benzo[ b]thiophenes.

ABSTRACT: The first example of near-room-temperature ?-arylation of benzo[ b]thiophenes is reported. The discovery rests on the observation of a switch in ?-/?-regioselectivity at different loadings of Pd₂(dba)₃·CHCl₃ in the coupling between benzo[ b]thiophene and 4-iodotoluene. We show that this unprecedented regioselectivity switch is driven by a Ag(I)-mediated C-H activation at the ?-C-H position, which becomes the dominant mode of reactivity at low concentrations of Pd. Competition experiments, kinetic studies, KIE, and D/H scrambling experiments have been carried out supporting this mechanism.

SUBMITTER: Colletto C

PROVIDER: S-EPMC6370252 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature

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Ag(I)-C-H Activation Enables Near-Room-Temperature Direct α-Arylation of Benzo[ b]thiophenes.

Colletto Chiara C Panigrahi Adyasha A Fernández-Casado Jaime J Larrosa Igor I

Journal of the American Chemical Society 20180723 30

The first example of near-room-temperature α-arylation of benzo[ b]thiophenes is reported. The discovery rests on the observation of a switch in α-/β-regioselectivity at different loadings of Pd2(dba)3·CHCl3 in the coupling between benzo[ b]thiophene and 4-iodotoluene. We show that this unprecedented regioselectivity switch is driven by a Ag(I)-mediated C-H activation at the α-C-H position, which becomes the dominant mode of reactivity at low concentrations of Pd ...[more]

PMID: 29983049

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