Asymmetric Catalysis in the Excited State

Chemistry and Biomolecular Sciences Seminar
Wednesday, 18 December 2019 - 1:00 pm
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Free of charge
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Who: Prof. Paolo Melchiorre, ICIQ - Avinguda Països Catalans, 16 43007 (Tarragona, Spain), ICREA - Pg. Lluís Companys 23, 08010 (Barcelona, Spain)

When: Dec 18 2019, 1pm

Where: STEM Complex, room 224

Abstract

The chemical reactivity of electronically excited molecules differs fundamentally from that in the ground state. This is the underlying reactivity concept of photochemistry,1 which has traditionally allowed the development of unique chemical transformations not achievable via conventional ground-state pathways.2 For example, an excited-state molecule is both a better electron-donor (i.e. a better reductant) and electron-acceptor (i.e. a better oxidant) than in the ground state. This explains why the light excitation of organic molecules can unlock unconventional reactivity manifolds. In this context, our laboratory has been exploring the potential of some organocatalytic and organometallic intermediates to directly reach an electronically excited state upon visible-light absorption to then switch on novel catalytic functions that are unavailable to ground-state organocatalysis.3 Studying the mechanism of these photochemical approaches allowed us to expand the synthetic possibilities offered by the excited-state reactivity of organocatalytic intermediates.4

Reference
  1. Balzani, V.; Ceroni, P.; Juris, A. Eds. in Photochemistry and Photophysics, Wiley-VCH, 2014.
  2. Albini, A.; Fagnoni, M. Eds. in Handbook of Synthetic Photochemistry, Wiley-VCH, 2010.
  3. (a) Arceo, E.; Jurberg, I. D.; Álvarez-Fernández, A.; Melchiorre, P. Nature Chem. 2013, 5, 750–756. (b) Murphy, J. J.; Bastida, D.; Paria, S.; Fagnoni, M.; Melchiorre, P. Nature 2016, 532, 218–222.
  4. Silvi, M.; Melchiorre, P. Nature 2018, 554, 41-49.