Ligand-enabled ?-C-H arylation of ?-amino acids using a simple and practical auxiliary.

ABSTRACT: Pd-catalyzed ?-C-H functionalizations of carboxylic acid derivatives using an auxiliary as a directing group have been extensively explored in the past decade. In comparison to the most widely used auxiliaries in asymmetric synthesis, the simplicity and practicality of the auxiliaries developed for C-H activation remains to be improved. We previously developed a simple N-methoxyamide auxiliary to direct ?-C-H activation, albeit this system was not compatible with carboxylic acids containing ?-hydrogen atoms. Herein we report the development of a pyridine-type ligand that overcomes this limitation of the N-methoxyamide auxiliary, leading to a significant improvement of ?-arylation of carboxylic acid derivatives, especially ?-amino acids. The arylation using this practical auxiliary is applied to the gram-scale syntheses of unnatural amino acids, bioactive molecules, and chiral bis(oxazoline) ligands.

SUBMITTER: Chen G 

PROVIDER: S-EPMC4432912 | biostudies-literature | 2015 Mar

REPOSITORIES: biostudies-literature