RT Journal Article T1 Origin of the Felkin-Anh(-Eisenstein) Model: a Quantitative Rationalization of a Seminal Concept A1 González Pinardo, Daniel A1 Bickelhaupt, F. Matthias A1 Fernández López, Israel AB Quantum chemical calculations were carried out to quantitatively understand the origin of the Felkin–Anh(–Eisenstein) model, widely used to rationalize the π-facial stereoselectivity in the nucleophilic addition reaction to carbonyl groups directly attached to a stereogenic center. To this end, the possible approaches of cyanide to both (S)-2-phenylpropanal and (S)-3-phenylbutan-2-one have been explored in detail. With the help of the activation strain model of reactivity and the energy decomposition analysis method, it is found that the preference for the Felkin–Anh addition is mainly dictated by steric factors which manifest in a less destabilizing strain-energy rather than, as traditionally considered, in a lower Pauli repulsion. In addition, other factors such as the more favorable electrostatic interactions also contribute to the preferred approach of the nucleophile. Our work, therefore, provides a different, more complete rationalization, based on quantitative analyses, of the origin of this seminal and highly useful concept in organic chemistry. PB Royal Society of Chemistry YR 2024 FD 2024 LK https://hdl.handle.net/20.500.14352/109214 UL https://hdl.handle.net/20.500.14352/109214 LA eng NO D. González-Pinardo, F. M. Bickelhaupt and I. Fernández, Origin of the Felkin–Anh(–Eisenstein) model: a quantitative rationalization of a seminal concept, Chem. Sci., 2024, 15, 12380–12387. NO 2024 Acuerdos transformativos CRUE NO Ministerio de Ciencia, Innovación y Universidades (España) NO Dutch Research Council (Holanda) DS Docta Complutense RD 18 abr 2025