Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Radical additions to olefins and related π-systems are essential tools in the modern synthetic toolbox for forging C–C and C–X bonds. We report a systematic DFT study (ZORA-(U)OLYP/TZ2P) on methyl radical (H 3 C • ) additions to H 2 C═X substrates, where X is varied across elements from the tetrel (group 14: C, Si, Ge), pnictogen (group 15: N, P, As), and chalcogen (group 16: O, S, Se) groups. Our analysis reveals clear periodic trends: addition barriers at carbon decrease, and those at X increase from tetrels to chalcogens; reaction energies become less favorable across a period but more favorable down a group. Regioselectivity favors addition at X except for X = CH 2, NH, and O, where carbon attack dominates─consistent with experimental data. These trends arise from a balance of orbital interactions and Pauli repulsion, with the latter emerging as a key, yet underappreciated, factor governing radical reactivity and regioselectivity in π-systems.
Source: The Journal of Organic Chemistry
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
OpenAlex ID: W4412515700