Enantioselective Palladium-Catalyzed Decarboxylative Allylation of Carbazolones and Indolones: Formal Synthesis of (+)-Kopsihainanine A

摘要

The elaboration of readily available nitrogen heterocycles to complex targets is integral to medicinal and natural products chemistry, as such new strategies to derivatize heterocycles retain relevance. As part of ongoing studies on alkaloid synthesis, we noted a lack of direct enantioselective methods for the assembly of C3-chiral carbazolones (i.e., 1), motifs common in medicinal and natural products chemistry (Scheme 1). This is a striking observation, as a host of methods for the stereoselective installation of functionality a to the carbonyl functionality of the parent carbazolone should potentially be viable. Furthermore, our examination of the literature reveals only one, ultimately unsuccessful, attempt to demonstrate this strategy.