Journal article

Publication year: 2021

Pages: 7701-7713

Journal: The Journal of Organic Chemistry

Volume number: 86

Issue number: 11

ISSN: 0022-3263

DOI Link: https://doi.org/10.1021/acs.joc.1c00767

Publisher: American Chemical Society

Abstract: 
Halogens are rarely considered as dispersion energy donors for organic reaction design. Here, we re-examine one of the textbook examples for assessing steric hindrance, the A-value, and demonstrate that even in this system, halogens cannot be treated solely as classic repulsive hard spheres. A significant part of the steric demand of the halogens is compensated by attractive London dispersion (LD) interactions, explaining the experimental lack of a clear trend when going down the halogens' row. Beyond monohalogenated cyclohexanes, dihalo- and perhalocyclohexanes also show significant LD interactions. We also explored several other small organic systems containing halogens. Our findings show that organic chemists should treat halogens as possible sources of LD interactions in reaction design, as these atoms can change the landscape of the potential energy surface and reverse trends of conformer stabilities and reaction selectivities.

Harvard Citation style: Solel, E., Ruth, M. and Schreiner, P. (2021) London Dispersion Helps Refine Steric A-Values: The Halogens, The Journal of Organic Chemistry, 86(11), pp. 7701-7713. https://doi.org/10.1021/acs.joc.1c00767

APA Citation style: Solel, E., Ruth, M., & Schreiner, P. (2021). London Dispersion Helps Refine Steric A-Values: The Halogens. The Journal of Organic Chemistry. 86(11), 7701-7713. https://doi.org/10.1021/acs.joc.1c00767