Synthesis 2017; 49(02): 319-325
DOI: 10.1055/s-0036-1589408
paper
© Georg Thieme Verlag Stuttgart · New York

Concentration Effect in the Asymmetric Michael Addition of Acetone to β-Nitrostyrenes Catalyzed by Primary Amine Thioureas

Z. Inci Günler
a   Department of Biological Chemistry and Molecular Modelling, Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain   Email: ciril.jimeno@iqac.csic.es
,
Ignacio Alfonso
a   Department of Biological Chemistry and Molecular Modelling, Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain   Email: ciril.jimeno@iqac.csic.es
,
Ciril Jimeno*
a   Department of Biological Chemistry and Molecular Modelling, Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain   Email: ciril.jimeno@iqac.csic.es
,
Miquel A. Pericàs*
b   Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Av. Països Catalans 16, 43007 Tarragona, Spain
c   Departament de Química Inorgànica i Orgànica, Universitat de Barcelona, 08028 Barcelona, Spain   Email: mpericas@iciq.es
› Author Affiliations
Further Information

Publication History

Received: 28 September 2016

Accepted after revision: 07 October 2016

Publication Date:
14 November 2016 (online)


Dedicated to Professor Dieter Enders on the occasion of his 70th birthday

Abstract

Bifunctional primary amine thiourea (PAT) organocatalysts show remarkable improvement in enantioselectivity and catalytic activity (turnover frequency) in the asymmetric Michael addition of acetone to β-nitrostyrenes upon dilution. Mechanistic investigations indicate that this behavior corresponds to the inhibition of off-cycle catalyst deactivation at low concentration, rather than to the operation of aggregation phenomena at high concentration. Reaction at low concentration (≤0.2 M in β-nitrostyrene) leads to the minimization of catalyst deactivation and, thus, to the optimization of yield and ee of the Michael­ addition products.

Supporting Information