Download PDF
Synfacts 2014; 10(12): 1273
DOI: 10.1055/s-0034-1379531
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart · New York

Fe(III)-Catalyzed Enantioselective Conia-ene Reaction

Contributor(s):
Mark Lautens
,
Christine M. Le
Shaw S, White JD * Oregon State University, Corvallis, USA
A New Iron(III)-Salen Catalyst for Enantioselective Conia-ene Carbocyclization.

J. Am. Chem. Soc. 2014;
136: 13578-13581
CrossrefGoogle Scholar
Further Information

Publication History

Publication Date:
18 November 2014 (online)

 
 PDF Download Permissions and Reprints

Key words

iron - salen ligands - Conia-ene reaction - carbocyclization

Significance

The Conia-ene reaction represents a powerful approach to form chiral all-carbon quaternary centers (see Review below). Current methods for the enantioselective Conia-ene reaction commonly employ a dual catalytic system comprised of a hard and a soft Lewis acid (selected references: B. K. Corkey, F. D. Toste J. Am. Chem. Soc. 2005, 127, 17168; T. Yang et al. J. Am. Chem. Soc. 2009, 131, 9140; A. Matsuzawa et al. Angew. Chem. Int. Ed. 2011, 50, 7616). White and co-workers now report that a single Fe(III)–salen catalyst can efficiently promote the enantioselective Conia-ene reaction with high ­enantioselectivities.


#

Review

F. Dénès et al. Chem. Rev. 2010, 110, 2366-2447.


#

Comment

The method developed by White and co-workers provides access to the desired carbocycles in generally very high yields (>90%) and enantioselectivities (>90%). In addition to the formation of 5-membered rings, larger (6,7) and smaller (4) rings can also be formed – albeit in lower yields and enantioselectivities in the latter case. The authors propose that the Fe(III) catalyst serves to simultaneously activate the alkyne towards nucleophilic attack, as well as form the key metal enolate species.


#
#


   Permissions and Reprints