Thiol Additions to 1,4-Napthoquinone Epoxide Derivatives in the Presence of a Base
Derivatives of 1,4-napthoquinone are known to possess numerous biological activities, including potential anti-cancer properties. Their reactivity toward a nucleophile is responsible for many of these biological activities. Here, we studied the reaction of 2,3-dihydro-1,4-napthoquinone epoxide derivatives with alkylthiols, a process that requires the presence of a base. When 2-methyl-2,3-dihydro-1,4-naphthoquinone epoxide was reacted, two different classes of products were identified. The base strength controls the formation of the two different products. The first was the ?one-to-one? product, where one molecule of thiol reacts with each molecule of 1,4-napthoquinone derivative. The ?one-to-one? product was exclusively formed when the base used was mild, such as N-methylimidazole. In order to yield the ?two-to-one? product, two thiols for every 1,4-napthoquionone derivative, we found that the reaction required a stronger base, for example, triethylamine. The ?two-to-one? product was formed via the Michael addition process with the ?one-to-one? product as an intermediate. To shed light on the reaction mechanism for the formation of these two products the reaction 2,3-dimethyl-2,3-dihydro-1,4-naphthoquinone epoxide was studied. Also, we observed the reactions with both compound and several different thiols. The mechanism of the formation of these products is presented.
Geleris, Joshua, "Thiol Additions to 1,4-Napthoquinone Epoxide Derivatives in the Presence of a Base" (2005). URC Student Scholarship.
Sherman Fairchild Foundation Grant