RESUMEN
The efficient construction of cyclopropyl spiroindoline skeletons and the exploration of related follow-up synthetic transformations have elicited considerable interest amongst members of the chemistry community. Here, we describe a formal (2 + 1) annulation and three-component (1 + 1 + 1) cascade cyclisation via sulphur ylide cyclopropanation under mild conditions. The spiro-cyclopropyl iminoindoline moiety can be readily transformed into another medicinally interesting pyrrolo[3,4-c]quinoline framework through a novel rearrangement process.
Asunto(s)
Azufre , CiclizaciónRESUMEN
The Suzuki-Miyaura cross-coupling of C(sp3)-hybridised boronic compounds still remains a challenging task, thereby hindering the broad application of alkyl boron substrates in carbon-carbon bond-forming reactions. Herein, we developed an NHC/photoredox dual catalytic cross-coupling of alkyl trifluoroborates with acid fluorides, providing an alternative solution to the classical acylative Suzuki coupling chemistry. With this protocol, various ketones could be rapidly synthesised from readily available materials under mild conditions. Preliminary mechanistic studies shed light on the unique radical reaction mechanism.
RESUMEN
Efficient construction of medium-sized lactones has attracted considerable interest over several decades, but remains a formidable challenge in synthetic chemistry. Here, we describe an unprecedented palladium-catalysed regioselective [5 + n] cyclisation (n = 5, 6, and 7) between vinylethylene carbonates and various anhydrides. Catalytic transformation occurs under mild, room-temperature conditions and offers an exceptional substrate scope. A broad spectrum of medium-sized bislactones with skeletal diversity can be obtained easily.