Density functional theory (DFT) has been used to investigate the mechanism of the experimentally efficient hydroalkylation of styrene with acetylacetone in the presence of a bismuth catalyst. It is shown that the mechanism is fundamentally different to that of the analogous gold-catalysed reaction, even though it leads to the same product. Whereas gold prefers to coordinate to the π-bond of the enol isomer of acetylacetone, bismuth coordinates to the two oxygens to form a chelated complex. Furthermore, the overall reaction with bismuth via the enol isomer of acetylacetone occurs with a much lower activation energy compared to the ketone isomer. In addition, several bismuth catalysts were considered and two of these were shown to have no activity. All of these results have been rationalised in terms of the strength of binding of the metal centres to the acetylacetone. The stronger the binding, the greater the acidity of a proton on acetylacetone, and thus the lower the activation energy for the protonation of styrene, which turns out to be the rate-determining step in the overall reaction. In this way, good agreement is obtained with all the experimental data.

Item Type:	Refereed Article
Keywords:	density functional theory (DFT), bismuth(III) catalysis, reaction mechanism, hydroalkylation, styrene
Research Division:	Chemical Sciences
Research Group:	Theoretical and computational chemistry
Research Field:	Computational chemistry
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the chemical sciences
UTAS Author:	Jalali, M (Ms Mona Jalali)
UTAS Author:	Bissember, AC (Associate Professor Alex Bissember)
UTAS Author:	Yates, BF (Professor Brian Yates)
UTAS Author:	Ariafard, A (Associate Professor Alireza Ariafard)
ID Code:	151113
Year Published:	2022
Web of Science® Times Cited:	1
Deposited By:	Chemistry
Deposited On:	2022-07-19
Last Modified:	2022-09-07
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