摘要：

The mechanism of a typical Petasis-type boronic mannich reaction (the styrylboronic acid, dibenzylamine, and α-hydroxylpropionaldehyde) has been investigated using density functional theory calculations. According to our calculations, the reaction is most likely to proceed through the following steps: 1) the nucleophilic addition of the amine to the aldehyde to form the carbinolamine; 2) the dehydration of the carbinolamine; 3) the formation of the tetra-coordinated borate intermediate; 4) the C-C bond formation by the intramolecular transfer of the styryl group; 5) the hydrolysis of the resulting intermediate to give the final products. The highest point on the energy profile is the transition state for the C-C bond formation (118.8 kJ·mol~(-1) above the reactants in ethanol). Our results can give reasonable explanations on some experimental facts observed for many Petasis-type boronic Mannich reactions.

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