Publication Details:
Title: Dimethyl Sulfoxide and N-Iodosuccinimide Promoted 5-exo-dig Oxidative Cyclization of Yne-Tethered Ynamide: Access to Pyrrolidones and Spiro-pyrrolidones
| Author(s) | B Prabagar, Sanatan Nayak, Rangu Prasad, Akhila K Sahoo : Org. Lett., 2016, 18, 3066–3069 |
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| Journal Name | Organic Letters |
| journal image URL | http://chemistry.uohyd.ac.in/~aks/wp-content/uploads/majjiorglettnew.png |
More Details:
An unprecedented metal-free dimethyl sulfoxide (DMSO) and N-iodosuccinimide mediated regioselective 5-exo-dig oxidative cyclization of an in situ generated enol equivalent of amides from ynamides bearing internal alkynes is demonstrated. The reaction allows easy access to functionalized pyrrolidone skeletons. Pyrrolidones having 3-o-biaryl motifs successfully undergo intramolecular electrophilic cyclization with the α,β-unsaturated olefin, furnishing spiro-pyrrolidone motifs. A one-pot sequential 5-exo-dig cyclization of the yne-tethered ynamides, followed by electrophilic cyclization of the pyrrolidone, is presented. The role of DMSO in the transformation is clarified, and a tentative reaction pathway is proposed.