Chemistry Weekly Seminar - Dr. Akkattu Biju, Indian Institute of Science Bangalore

Title

Molecular Rearrangements Involving Aryne Intermediates

Abstract

The chemistry of arynes has received incredible developments especially in transition-metal-free carbon-carbon and carbon-heteroatom bond-forming reactions in the last three decades.¹ The rapid growth in this field is mainly due to the development of mild methods for the generation of arynes. One aspect of the recent developments in the chemistry of arynes involve the molecular rearrangements proceeding via this electrophilic intermediate.² In the context of our interest in the chemistry of arynes,³ in 2013, have employed arynes in a three-component coupling triggered by pyridine and N-substituted isatins resulting in the synthesis of indolin-2-one derivatives proceeding via a unique rearrangement.⁴ Subsequently, we engaged this highly electrophilic intermediates in a three-component coupling involving aromatic tertiary amines, and aldehydes/CO₂ for the synthesis of 2-substituted aromatic tertiary amines.⁵ Moreover, the aryne triggered Stevens [2,3] rearrangement for the synthesis of homoallylic amines/thioethers has been demonstrated.⁶ Very recently, we employed arynes in Sommelet-Hauser rearrangement for the synthesis of a-aryl amino acid derivatives.⁷

The molecular rearrangements have provided direct access to a library of valuable molecules, which cannot be accessed in a single step through other synthetic routes. In this presentation, a summary of our group activity in this area will be highlighted.

References

For reviews, see: (a) Shi, J.; Li, Y.; Li, Y. Chem. Soc. Rev. 2017, 46, 1707. (b) García-López, J.-A.; Greaney, M. F. Chem. Soc. Rev. 2016, 45, 6766. (c) Dubrovskiy, A. V.; Markina, N. A.; Larock, R. C. Org. Biomol. Chem. 2013, 11, 191. (d) Tadross, P. M.; Stoltz, B. M. Chem. Rev. 2012, 112, 3550. (e) Gampe, C. M.; Carreira, E. M. Angew. Chem., Int. Ed. 2012, 51, 3766. (f) Bhunia, A.; Yetra, S. R.; Biju, A. T. Chem. Soc. Rev. 2012, 41, 3140.

For a review on aryne-triggered rearrangements, see: Roy, T.; Biju, A. T. Chem. Commun. 2018, 54, 2580.

Bhojgude, S. S.; Bhunia, A.; Biju, A. T. Acc. Chem. Res. 2016, 49, 1658.

(a) Bhunia, A.; Roy, T.; Pachfule, P.; Rajamohanan, P. R.; Biju, A. T.  Angew. Chem. Int. Ed. 2013, 52, 10040. See also: (b) Bhunia, A.; Porwal, D.; Gonnade, R. G.; Biju, A. T. Org. Lett. 2013, 15, 4620.

(a) Bhojgude, S. S.; Baviskar, D. R.; Gonnade, R. G.; Biju, A. T. Org. Lett. 2015, 17, 6270. (b) Bhojgude, S. S.; Roy, T.; Gonnade, R. G.; Biju, A. T. Org. Lett. 2016, 18, 5424.

(a) Roy, T.; Thangaraj, M.; Kaicharla, T.; Kamath, R. V.; Gonnade, R. G.; Biju, A. T. Org. Lett. 2016, 18, 5428. (b) Thangaraj, M.; Gaykar, R. N.; Roy, T.; Biju, A. T. J. Org. Chem. 2017, 82, 4470. (c) Bhattacharjee, S.; Guin, A.; Gaykar, R. N.; Biju, A. T. Org. Lett. 2019, 21, 4383. (d) Gaykar, R. N.; Guin, A.; Bhattacharjee, S.; Biju, A. T. Org. Lett. 2019, 21, 9613.

Roy, T.; Gaykar, R. N.; Biju, A. T. Chem. Commun. 2019, 55, 3004.

Date:       Friday, September 25, 2020

Time:      1:30 p.m.

Via Zoom video conference (link available by request to chem.dept@usask.ca)