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1-Aminopyridinium Ylides as Monodentate Directing Groups for sp3 C-H Bond Functionalization.

ABSTRACT: 1-Aminopyridinium ylides are efficient directing groups for palladium-catalyzed ?-arylation and alkylation of sp3 C-H bonds in carboxylic acid derivatives. The efficiency of these directing groups depends on the substitution at the pyridine moiety. The unsubstituted pyridine-derived ylides allow functionalization of primary C-H bonds, while methylene groups are unreactive in the absence of external ligands. 4-Pyrrolidinopyridine-containing ylides are capable of C-H functionalization in acyclic methylene groups in the absence of external ligands, thus rivaling the efficiency of the aminoquinoline directing group. Preliminary mechanistic studies have been performed. A cyclopalladated intermediate has been isolated and characterized by X-ray crystallography, and its reactivity was studied.

SUBMITTER: Le KKA

PROVIDER: S-EPMC6880753 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature

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1-Aminopyridinium Ylides as Monodentate Directing Groups for sp3 C-H Bond Functionalization.

Le Ky Khac Anh KKA Nguyen Hanh H Daugulis Olafs O

Journal of the American Chemical Society 20190906 37

1-Aminopyridinium ylides are efficient directing groups for palladium-catalyzed β-arylation and alkylation of sp3 C-H bonds in carboxylic acid derivatives. The efficiency of these directing groups depends on the substitution at the pyridine moiety. The unsubstituted pyridine-derived ylides allow functionalization of primary C-H bonds, while methylene groups are unreactive in the absence of external ligands. 4-Pyrrolidinopyridine-containing ylides are capable of C-H functionalization i ...[more]

PMID: 31529954

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