Mechanistic insights for the transprotection of tertiary amines with Boc(2)O via charged carbamates: access to both enantiomers of 2-azanorbornane-3-exo-carboxylic acids

• Tipo: Artigo em Revista Científica Internacional
• Data: 2019

Autores

Sampaio Dias, IE (Autor) Outra; Silva Reis, SC (Autor) Outra; da Silva, LP (Autor) FCUP; Garcia Mera, X (Autor) Outra; Maestro, MA (Autor) Outra; Rodriguez Borges, JE (Autor) FCUP

Revista

Título: Organic Chemistry Frontiers

Vol. 6

Páginas: 3540-3554

ISSN: 2052-4110

Editora: Royal Society of Chemistry

Indexação

ISI Web of Knowledge - 2 Citações

Scopus - 2 Citações

Outras Informações

ID Authenticus: P-00R-5MN

DOI: 10.1039/c9qo00957d

Abstract (EN): Herein we present a new synthesis methodology for the transprotection of the 1-phenylethyl protected tertiary amines to tert-butyloxycarbonyl (Boc) derivatives under exocyclic N-C hydrogenolysis catalyzed by Pd/C. We provide mechanistic insights into the N-dealkylation of hindered tertiary amines under the unrecognized role of tert-butyloxycarbonyl anhydride (Boc(2)O) as an additive to effectively promote the exocyclic N-C hydrogenolysis of tertiary amines by disclosing the role of Boc(2)O, which was not fully understood and studied until now. NMR and in silico experiments suggest the formation of a transient charged carbamate as the plausible intermediate. This selective transprotection enabled the development of a robust stereoselective methodology for the preparation of both enantiomers of 2-azanorbornane-3-exo-carboxylates by highly asymmetric aza-Diels-Alder reactions using (-)-8-phenylmenthol (8PM) and (+)-8-phenylneomenthol (8PnM) as chiral auxiliaries.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 15