Can one steer the course of a reaction by selectively applying a force to a molecule? Atomic force microscopy opens up this avenue. Martinez1 has just published a computational study on the ring opening of cyclobutene with applied forces. Cyclobutene should ring-open in a conrotatory fashion according to the Woodward-Hoffman rules. But Martinez shows that by pulling on cyclobutene in a cis fashion, the disrotatory pathway can become the more favored route. Thus, it appears that mechanochemistry might be an alternative way to create selectivity in chemical reactions!
References
(1) Ong, M. T.; Leiding, J.; Tao, H.; Virshup, A. M.; Martinez, T. J., “First Principles Dynamics and Minimum Energy Pathways for Mechanochemical Ring Opening of Cyclobutene,” J. Am. Chem. Soc., 2009, 131, 6377-6379, DOI: 10.1021/ja8095834.
InChIs
cyclobutene: InChI=1/C4H6/c1-2-4-3-1/h1-2H,3-4H2
InChIKey: CFBGXYDUODCMNS-UHFFFAOYAN
Computational Organic Chemistry » Mechanochemistry II responded on 20 Dec 2010 at 9:26 am #
[…] of Woodward-Hoffman forbidden ring opening of cyclobutene under mechanical stress.1 (See this blog post discussing the earlier work of Martinez.2) Pulling on cis substituents of a cyclobutene causes the […]