Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
J Am Chem Soc. 2008 Jan 23;130(3):1003-11.

Polarizing the Nazarov cyclization: the impact of dienone substitution pattern on reactivity and selectivity.

Author information

  • 1Department of Chemistry, University of Rochester, Rochester, New York 14627, USA.

Abstract

The impact of dienone substitution on the Nazarov cyclization has been examined in detail. Substrates bearing different substituents at each of four positions on the dienone backbone were systematically probed in order to identify trends leading to higher reactivity and better selectivity. Desymmetrization of the pentadienyl cation and oxyallyl cation intermediates through placement of polarizing groups at both the C-2 and C-4 positions was found to be particularly effective. These modifications allowed cyclizations to occur in the presence of catalytic amounts of mild Lewis acids. It was also found that stereoconvergent cyclization of mixtures of E and Z isomers of alkylidene beta-ketoesters occurred via an efficient isomerization process that occurred under the reaction conditions.

PMID:
18161974
[PubMed]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for American Chemical Society
    Loading ...
    Write to the Help Desk