Cycloreversion of beta-lactams via photoinduced electron transfer

The radical anions of beta-lactams, photogenerated in the presence of DABCO as an electron donor, undergo cycloreversion via N-C4 bond cleavage, back electron transfer and final C2-C3 bond cleavage, leading to olefins. The involved intermediates are 1,4-radical anions and 1,4-biradicals. The experimental observations are consistent with the results of DFT calculations.Financial support from the Spanish Government (CTQ2013-47872-C2-1-P, SEV-2012-0267, BES-2011-043706, JCI-2010-06204), from CSIC (JAEDOC 101-2011 co-funded by FSE) and from the Generalitat Valenciana (PROMETEOII/2013/005) is gratefully acknowledged. J. A. S. acknowledges the computational facilities provided by the Theoretical Computational Chemistry Group of Prof. L. R. Domingo at the Universitat de Valencia.Pérez Ruiz, R.; Sáez Cases, JA.; Jiménez Molero, MC.; Miranda Alonso, MÁ. (2014). Cycloreversion of beta-lactams via photoinduced electron transfer. 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