Department of Chemistry
Indian Institute of Technology Delhi

Thiol-Ene Reactions on Unsaturated Carbohydrates and Nucleosides

Dr. Anikó Borbás
Department of Pharmaceutical Chemistry, University of Debrecen, Hungary *

Date: December 8th 2017 (Friday)
Time: 4 PM
Venue: Committee Room, Chemistry Department, 6th Floor

Over the last decade, the photoinduced thiol-ene coupling, where a reactive thiyl radical undergoes an addition reaction onto a terminal alkene to furnish a thioether linkage, has been recognized as a robust ligation tool possessing many of the attributes of click chemistry. The reaction is insensitive to water and oxygen, requires very mild conditions, proceeds with exquisite regioselectivity and high yields and shows tolerance to a wide range of functional groups. The great synthetic potential of this metal-free reaction has been amply demonstrated in areas of polymer chemistry and material sciences, and in the field of bioorganic chemistry.1 We have investigated the addition of thiol-containing peptides and sugars to 2-acetoxy-D-glucal as a method for the synthesis of S-linked disaccharides and glycoconjugates with exclusive 1,2-cis-alfa-selectivity.2 The reaction has been extended to 2-acetamido-D-glucal and a range of 2-acetoxy-D- and L-glycals. Various sugar derived alkenes with exo- and endocyclic double bonds have been employed as acceptor substrates in the thiol-ene chemistry to produce thio-linked or sulfur-carbon-bridged disaccharides and glycoconjugates with high stereoselectivity.3 A low-temperature-photoinduced thiol-ene click reaction has been proved as a mild and efficient method for the synthesis of sugar modified nucleosides.4 In this lecture, our recent work in the field of thiol-ene chemistry will be presented..

  1. a) A. Dondoni, Angew. Chem., Int. Ed. 2008, 47, 8995−8997; b) C. E. Hoyle, C. N. Bowman, Angew. Chem., Int. Ed. 2010, 49, 1540−1573; c) F. Dénès, M. Pichowicz, G. Povie and P. Renaud, Chem. Rev. 2014, 114, 2587−2693; d) L. McSweeney, F. Dénès, E. M. Scanlan, Eur. J. Org. Chem. 2016, 2080−2095.
  2. L. Lázár, M. Csávás, M. Herczeg, P. Herczegh, A. Borbás, Org. Lett. 2012, 14, 4650−4653.
  3. a) L. Lázár, M. Csávás, Á. Hadházi, M. Herczeg, M. Tóth, L. Somsák, T. Barna, P. Herczegh, A. Borbás, Org. Biomol. Chem. 2013, 11, 5339−5350; b) L. Lázár, M. Csávás, M. Tóth, L. Somsák, A. Borbás, Chem. Pap. 2015, 69, 889−895.
  4. (a) M. Bege, I. Bereczki, M. Herczeg, M. Kicsák, D. Eszenyi, P. Herczegh, A. Borbás, Org. Biomol. Chem. 2017, 15, 9226-9233.

All are cordially invited to attend.
Convener (Seminars)