Facile reductive amination of aldehydes with electron-deficient anilines by acyloxyborohydrides in TFA: application to a diazaindoline scale-up.

Autor: Boros EE; GlaxoSmithKline Research & Development, Five Moore Drive, Research Triangle Park, North Carolina 27709, USA. eric.e.boros@gsk.com, Thompson JB, Katamreddy SR, Carpenter AJ
Jazyk: angličtina
Zdroj: The Journal of organic chemistry [J Org Chem] 2009 May 01; Vol. 74 (9), pp. 3587-90.
DOI: 10.1021/jo900157z
Abstrakt: A scale-up of diazaindoline 1 was achieved in four stages and 32% overall yield. The key step involved rapid reductive amination of aldehyde 8 with aniline 5 by sodium triacetoxyborohydride (STAB-H) and TFA followed by ring closure of intermediate amine 9 to compound 1 in the same pot. These reaction conditions were also applied to facile reductive aminations with anilines known to have little reactivity under STAB-H/AcOH conditions. Spectral data supported the tris(trifluoroacetoxy)borohydride anion (16) as the active reducing agent.
Databáze: MEDLINE