ホウ素およびケイ素エノラート間の酸化的クロスカップリング

抄録

Intermolecular oxidative cross-coupling of enolate species is a useful reaction for the direct synthesis of unsymmetrical 1,4-dicarbonyl compounds. 1,4-Dicarbonyl compounds are important not only as structures found in natural products, pharmaceuticals, and their synthetic intermediates, but also as building blocks for the construction of heterocyclic compounds. The difficulty in the oxidative cross-coupling lies in the cross-selectivity. The key point is how to suppress undesired homo-coupling. Since the cross-coupling must proceed between nucleophilic species in contrast to the commonly used nucleophile-electrophile coupling, some elaboration is required to achieve this. The author focused on the fact that the reactivity of the enolate anion changes depending on the metallic counter-cation. Specifically, we discovered that a combination of boron and silicon for the counter-cation of enolate clarifies the role of the two enolate species, and leads to the selective oxidative cross-coupling. This article summarizes our studies on the oxidative cross-coupling between boron and silicon enolates by oxovanadium(V) oxidant.