Abstract
DFT calculations have been carried out in order to rationalize and predict the ring-opening regioselectivity of substituted cyclopropenes in the presence of gold(I) catalysts. It has been shown that the regioselectivity of these ring-opening processes is driven by the relative π-donor ability of the substituents on the cyclopropene double bond (C1 and C2). A stronger π-donor substituent at C2 favors Au(I)-induced polarization of the double bond toward C1, resulting in preferential breaking of the C1-C3 bond. An excellent correlation between ΔE‡ and the difference in the C1-C2 p(π) orbital population was observed for a broad range of substituents, providing a useful predictive model for gold-induced cyclopropene ring-opening. Furthermore, it was found that the stability of the resulting gold-stabilized allyl-cation intermediates do not follow the same trend as the ring-opening reaction energies. Generally, the more facile ring-opening process led to the less thermodynamically stable intermediate, which lacked stabilization of the carbocation by a π-donor in the α-position.
Original language | English |
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Pages (from-to) | 9553-9559 |
Number of pages | 7 |
Journal | Journal of Organic Chemistry |
Volume | 78 |
Issue number | 19 |
Early online date | 26 Aug 2013 |
DOIs | |
Publication status | Published - 4 Oct 2013 |
ASJC Scopus subject areas
- Organic Chemistry