Bifunctional Squaramide Organocatalysts for the Asymmetric Addition of Formaldehyde tert-Butylhydrazone to Simple Aldehydes

The nucleophilic addition of formaldehyde tert-butylhydrazone to simple aldehydes (a formal hetero-carbonyl–ene reaction) can be performed with good reactivity and excellent enantioselectivity by virtue of the dual hydrogen-bonding activation exerted by amide–squaramide organocatalysts. The resultin...

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Bibliographic Details
Authors: Matador, Esteban, Retamosa Hernández, María Gracia, Monge, David, Iglesias-Sigüenza, Javier, Fernández, Rosario, Lassaletta, José M.
Format: article
Status:Versión aceptada para publicación
Publication Date:2018
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/169460
Online Access:http://hdl.handle.net/10261/169460
Access Level:Open access
Description
Summary:The nucleophilic addition of formaldehyde tert-butylhydrazone to simple aldehydes (a formal hetero-carbonyl–ene reaction) can be performed with good reactivity and excellent enantioselectivity by virtue of the dual hydrogen-bonding activation exerted by amide–squaramide organocatalysts. The resulting hydroxydiazenes (azo alcohols) were isolated in high yields as enantiomerically enriched azoxy compounds after a regioselective azo-to-azoxy transformation. Subsequent derivatization provides an entry to relevant amino alcohols, oxazolidinones, and derivatives thereof.