Synthesis of Various Spiro-Pyranooxoindoles Using Vitamin B12 as an Efficient Biocatalyst

Abstract

The present study aims to discuss the synthesis of various spiropyrano- oxoindole derivatives through a reaction involving isatin, malononitrile, and a CH-acid source in the presence of vitamin B12. Eco-friendly solvents were utilized to synthesize the spiro-pyranooxoindole, resulting in high yields of all synthesized heterocyclic systems. Isatin and malononitrile were reacted with β-dicarbonyls as CH-acids in the presence of vitamin B12. The results indicate that vitamin B12 is highly effective in generating spiro-pyranooxoindole derivatives. All synthesized compounds closely match previously reported compounds. In conclusion, a new and effective method for synthesizing spiro-pyrano-oxoindole has been demonstrated using vitamin B12 as a biocatalyst.