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Enantiomers of a compound interact differently with biological system. Whereas one of the enantiomers is beneficial for the treatment of particular
disease the other may be inactive or detrimental. This is why many of the building blocks of biological systems, such as sugars and amino acids,
are produced exclusively as one enantiomer. Therefore, asymmetric catalysis which yields compounds in enantioenriched form has emerged as
a pinnacle technology in the 21st century. Initially, glimpses of various asymmetric generic modes of activations (organocatalytic as well as metal
catalyzed reactions) which I have explored till date, will be demonstrated. Towards this, an organocatalytic direct aldol1a-c and Michael1d reactions
via enamine formation yielding synthetically useful chiral scaffolds (in >99% enantioselectivities) has been discussed using the prolinamide
(highlighted as Singh’s catalyst) and diamine catalysts respectively, developed by us. This will be followed by synthesis of chiral isoindolinones
and THIQ’s employing organocatalytic mannich2 type reactions as well as metal catalyzed (Cu(I)-Pybox) A3-Coupling.3 In this regard, several
lewis acid catalyzed synthesis of isoindolinones and THIQ’s has also been explored.4
Figure. Enabling synthesis through asymmetric catalysis.
Further, I will discuss asymmetric approach to the syntheses of lycoposerramine R,5 and sesquiterpene based naturally occurring secondary
metabolites (current work).6 Eventually, the presentation will be summarized with the future research proposals to be executed as an Independent
Investigator.
References:
1. (a) Vishnu Maya, Monika Raj, and Vinod K. Singh* Org. Lett. 2007, 9, 2593. (b) Monika Raj, Vishnu Maya and Vinod K. Singh* J. Org. Chem. 2009,
74, 4289. (c) Vishnumaya Bisai and Vinod K. Singh* Synlett 2011, 481. (d) Vishnu Maya and Vinod K. Singh* Org. Lett. 2007, 9, 1117.
2. Vishnumaya Bisai, Rajshekhar A. Unhale, Arun Suneja, S. Dhanasekharan, and Vinod K. Singh* Org. Lett. 2015, 17, 2102.
3. (a) Vishnumaya Bisai, Arun Suneja and Vinod K. Singh* Angew. Chem., Int. Ed. 2014, 53, 10737. (b) Arun Suneja; Vishnumaya Bisai and Vinod K.
Singh* J. Org. Chem. 2016, 81, 4779. (c) Vishnumaya Bisai, and Vinod K. Singh* Tetrahedron Letters 2016, 57, 4771.
4. (a) S. Dhanasekharan, Vishnumaya Bisai, Rajshekhar A. Unhale, Arun Suneja and Vinod K. Singh* Org. Lett. 2014, 16, 6068. (b) S. Dhanasekharan,
Anirban Kayet, Arun Suneja, Vishnumaya Bisai and Vinod K. Singh* Org. Lett. 2015, 17, 2780. (c) Raju Karmakar, Arun Suneja, Vishnumaya Bisai and
Vinod K. Singh* Org. Lett. 2015, 17, 5650. (d) S. Dhanasekharan, Arun Suneja, Vishnumaya Bisai and Vinod K. Singh* Org. Lett. 2016, 18, 634.
5. Vishnumaya Bisai and Richmond Sarpong* Org. Lett. 2010, 12, 2551.
6. (a) Arindam Khatua, Sovan Niyogi, and Vishnumaya Bisai* Org. Biomol. Chem. 2019, 17, 7140. (b) Mrinal K. Das, Bidyut K. Dinda, and Vishnumaya
Bisai* Tetrahedron Lett. 2019, 60, 2039. (c) Sovan Niyogi, Arindam Khatua, and Vishnumaya Bisai* Tetrahedron Lett. 2019, 60, 150941. |