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Ir-Catalyzed Enantioselective, Intramolecular Silylation of Methyl C-H Bonds.

ABSTRACT: We report highly enantioselective intramolecular, silylations of unactivated, primary C(sp3)-H bonds. The reactions form dihydrobenzosiloles in high yields with excellent enantioselectivities by functionalization of enantiotopic methyl groups under mild conditions. The reaction is catalyzed by an iridium complex generated from [Ir(COD)OMe]2 and chiral dinitrogen ligands that we recently disclosed. The C-Si bonds in the enantioenriched dihydrobenzosiloles were further transformed to C-Cl, C-Br, C-I, and C-O bonds in final products. The potential of this reaction was illustrated by sequential C(sp3)-H and C(sp2)-H silylations and functionalizations, as well as diastereoselective C-H silylations of a chiral, natural-product derivative containing multiple types of C-H bonds. Preliminary mechanistic studies suggest that C-H cleavage is the rate-determining step.

SUBMITTER: Su B

PROVIDER: S-EPMC5809130 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature

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Ir-Catalyzed Enantioselective, Intramolecular Silylation of Methyl C-H Bonds.

Su Bo B Hartwig John F JF

Journal of the American Chemical Society 20170825 35

We report highly enantioselective intramolecular, silylations of unactivated, primary C(sp<sup>3</sup>)-H bonds. The reactions form dihydrobenzosiloles in high yields with excellent enantioselectivities by functionalization of enantiotopic methyl groups under mild conditions. The reaction is catalyzed by an iridium complex generated from [Ir(COD)OMe]<sub>2</sub> and chiral dinitrogen ligands that we recently disclosed. The C-Si bonds in the enantioenriched dihydrobenzosiloles were further transf ...[more]

PMID: 28820264

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