Synlett 2013; 24(10): 1197-1200
DOI: 10.1055/s-0033-1338945
cluster
© Georg Thieme Verlag Stuttgart · New York

NHC-Catalyzed Ester Activation: Access to Sterically Congested Spirocyclic Oxindoles via Reaction of α-Aryl Esters and Unsaturated Imines

Lin Hao
Division of Chemistry & Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore   Fax: +65 67911961   Email: [email protected]
,
Chan Wei Chuen
Division of Chemistry & Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore   Fax: +65 67911961   Email: [email protected]
,
Rakesh Ganguly
Division of Chemistry & Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore   Fax: +65 67911961   Email: [email protected]
,
Yonggui Robin Chi*
Division of Chemistry & Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore   Fax: +65 67911961   Email: [email protected]
› Author Affiliations
Further Information

Publication History

Received: 01 April 2013

Accepted after revision: 19 April 2013

Publication Date:
17 May 2013 (online)


Abstract

Carboxylic esters can be readily obtained at low cost. Therefore, asymmetric catalytic activation of esters should provide useful strategies for organic synthesis. Here we report a N-heterocyclic carbene (NHC)-mediated reaction of α-aryl acetic esters with oxindole-derived α,β-unsaturated imines. The reaction involves the formation of NHC-bound ester enolate intermediate from an ester as a key step, and furnishes spirocyclic oxindole products. The sterically congested spirocyclic oxindole bears a newly formed six-membered δ-lactams and cannot be easily prepared using other methods.

Supporting Information

 
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