RESUMO
Fused furans are commonly found units in natural products and medicinal molecules, and methods for their introduction are of fundamental importance. Here we report one-pot cycloadditions of ethynyl indoloxazolidones with 1,3-cyclohexanediones enabled by copper catalysis, leading to a series of functionalized furan derivatives in good yields. This method features mild reaction conditions, high efficiency, and wide substrate scope.
RESUMO
Heterocyclic Quaternary Phosphonium Salts (HQPS) have emerged as promising chemicals for organic synthesis and medicinal chemistry. However, the present synthetic methodology of this type of compound is still limited. Here, we report a deconstructive reorganization strategy based on Brønsted acid-mediated tandem 1,4 addition/intramolecular cyclization of triphenylphosphine derivatives and in situ generated o-AQMs for the first time. This protocol provides a novel approach to heterocyclic quaternary phosphonium salts. The method also features a non-metal catalyst, mild reaction conditions, high efficiency and wide substrate scope. Moreover, a series of obtained heterocyclic phosphonium salts can be converted to isotopically labelled 2-benzofuran compounds directly by simple deuteration reactions.
RESUMO
The visible-light-promoted difunctionalization of alkenyl ketones has been developed for easy access of various tetralones, cyclopropane, or alkenyl migration compounds. With fac-[Ir(ppy)3] as the photocatalyst, alkenyl ketones captured the α-carbonyl alkyl radical and evolved through intramolecular cyclization and the elimination of a proton to give the difunctionalized products. This strategy is characterized by good yields, mild reaction conditions, and outstanding functional group tolerance.