Publication Details:
Title: Umpolung Reactivity of Ynamides: An Unconventional [1,3]‐Sulfonyl and [1,5]‐Sulfinyl Migration Cascade
| Author(s) | B Prabagar, Rajendra K Mallick, Rangu Prasad, Vincent Gandon, and Akhila K Sahoo : Angew.Chem. Int.Ed. 2019, 58, 2365 –2370 |
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| Journal Name | Angewandte Chemie International Edition |
| Link to | https://onlinelibrary.wiley.com/doi/epdf/10.1002/anie.201813143 |
| journal image URL | http://chemistry.uohyd.ac.in/~aks/wp-content/uploads/prabagaranie.png |
More Details:
A regioselective sulfonyl/sufinyl migration cycloisomerization cascade of alkyne‐tethered ynamides is developed in the presence of XPhos‐gold catalyst. This is the first example of a general [1,3]‐sulfonyl migration from the nitrogen to the β‐carbon of ynamides, followed by umpolung 5‐endo‐dig cyclization of the ynamide α‐carbon to the gold activated alkyne, and finally deaurative [1,5]‐sulfinylation. This process allows the synthesis of peripheral decorated unconventional 4‐sulfinylated pyrroles with a broad scope from N‐propargyl‐tethered ynamides. On the other hand, N‐homopropargyl‐tethered ynamides undergo intramolecular tetradehydro Diels‐Alder reaction to provide 2,3‐dihydro‐benzo[f]indole derivatives. Control experiments and density functional theory (DFT) studies help rationalizing these reaction pathways.