Unprecedented chemoselective Ru(iii)-catalyzed [3 + 2] annulation of enaminones with iodonium ylides for the synthesis of functionalized 3a,7a-dihydroxy hexahydro-4H-indol-4-ones

Abstract

Herein, a straightforward and efficient method to obtain 3a,7a-dihydroxy hexahydro-4H-indol-4-ones via Ru(III)-catalyzed alkenyl C(sp²)–H bond functionalization/[3 + 2] annulation of enaminones with iodonium ylides has been described. This protocol features chemoselectivity, broad substrate scope, moderate to excellent yields, gram-scale synthesis, and mild reaction conditions. The newly formed 3a,7a-dihydroxy hexahydro-4H-indol-4-one scaffolds can be easily further derivatized to 1H-pyrrol-3-ol carboxylate derivatives through an open-ring/hydrolysis transformation, showing potential applications in organic synthesis and medicinal chemistry.