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CO2_SO2_v2.pdf (1.72 MB)

CO2 or SO2: Should It Stay or Should It Go?

revised on 21.02.2019, 00:57 and posted on 21.02.2019, 16:04 by Gabriel dos Passos Gomes, Alexander Wimmer, Joel Smith, Burkhard König, Igor Alabugin

A broad computational analysis of carbon-centered radical formation via the loss of either CO2 or SO2 from the respective RXO2 radical precursors (X = C or S) reveals dramatic differences between these two types of dissociative processes. Whereas the C-C scission with the loss of CO2 is usually exothermic, the C-S scission with the loss of SO2 is generally endothermic. However, two factors can make the C-S scissions thermodynamically favorable: increased entropy, characteristic for the dissociative processes, and stereoelectronic influences of substituents. The threshold between endergonic and exergonic C-S fragmentations depends on subtle structural effects. In particular, the degree of fluorination in a radical precursor has a notable impact on the reaction outcome. This study aims to demystify the intricacies in reactivity regarding the generation of radicals from sulfinates and carboxylates, as related to their role in radical cross-coupling.


National Science Foundation (Grant CHE-1800329)


German Science foundation (GRK 1626; Koselleck)


Email Address of Submitting Author


Florida State University



ORCID For Submitting Author


Declaration of Conflict of Interest

We declare no conflict of interests.

Version Notes

Version 2 with updated plots and new MP2 data.