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Bronsted Acid-Catalyzed Epimerization-Free Preparation of Dual-Protected Amino Acid Derivatives.

ABSTRACT: An organocatalytic protocol, employing the commercially available EDC as coupling agent, has been developed for the preparation of dual-protected amino acid derivatives without epimerization. This methodology was then applied to different Boc-amino acid and amine derivatives in moderate to excellent isolated yields. In addition, racemization-free Boc deprotection was also demonstrated. Mechanism investigation through electrospray ionization (+)-mass spectrometry/mass spectrometry revealed an acyclic intermediate (no azlactone formation) activated by the camphorsulfonic acid as an organocatalyst as a key step for the sequential attack of the nucleophile.

SUBMITTER: de Castro PP

PROVIDER: S-EPMC6641006 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature

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Brønsted Acid-Catalyzed Epimerization-Free Preparation of Dual-Protected Amino Acid Derivatives.

de Castro Pedro P PP Rimulo Isabela M R IMR de Almeida Angelina M AM Diniz Renata R Amarante Giovanni W GW

ACS omega 20170627 6

An organocatalytic protocol, employing the commercially available EDC as coupling agent, has been developed for the preparation of dual-protected amino acid derivatives without epimerization. This methodology was then applied to different Boc-amino acid and amine derivatives in moderate to excellent isolated yields. In addition, racemization-free Boc deprotection was also demonstrated. Mechanism investigation through electrospray ionization (+)-mass spectrometry/mass spectrometry revealed an acy ...[more]

PMID: 31457632

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