Divergent Synthesis of Methylisatoid and Tryptanthrin Derivatives by Ph<sub>3</sub>P–I<sub>2</sub>-Mediated Reaction of Isatins with and without Alcohols
Mookda Pattarawarapan, Nittaya Wiriya, Surat Hongsibsong, Wong Phakhodee
Abstract
A novel phosphonium-mediated reaction of isatins is described. In the presence of alcohol, the reaction proceeds to furnish C-12 modified tryptanthrin derivatives. Without alcohol, self-dimerization of isatins gives rise to tryptanthrin and its analogs. This divergent and step-economic approach provides a facile access to diverse indoloquinazoline structures including the natural alkaloids, methylisatoid and cephalanthrin B, in high yields from simple precursors under mild and metal-free reaction conditions.
Topics & Concepts
IsatinChemistryAlcoholPhosphoniumDivergent synthesisReaction conditionsOrganic chemistryCombinatorial chemistryCatalysisQuinazolinone synthesis and applicationsCancer therapeutics and mechanismsSynthesis and Biological Evaluation