Guanidinium Hypoiodite-Catalyzed Intramolecular Oxidative Coupling Reaction of Oxindoles with β-Dicarbonyls

Spiro[indoline-3,4 & PRIME;-piperidine] is a fundamental motif present in various biologically active compounds. Here, we report an intramolecular oxidative coupling reaction of oxindoles with beta-dicarbonyls in the presence of a guanidinium hypoiodite catalyst, providing spiro-coupling products in moderate to excellent yields. Furthermore, a chiral hypoiodite catalyst derived from the chiral guanidinium organocatalyst is effective for the challenging asymmetric carbon-carbon bond-forming reaction, affording optically active spiro[indoline-3,4 & PRIME;-piperidines].

Automated summary

In this study, a new method for intramolecular oxidative coupling reaction of oxindoles with beta-dicarbonyls using a guanidinium hypoiodite catalyst was reported. The reaction resulted in the formation of spiro-coupling products in moderate to excellent yields. Furthermore, a chiral hypoiodite catalyst derived from the chiral guanidinium organocatalyst was found to be effective for the challenging asymmetric carbon-carbon bond-forming reaction, leading to the synthesis of optically active spiro[indoline-3,4'piperidines].