Synthesis of Indoline‐Fused 2,5‐Diketopiperazine Scaffolds <i>via</i> Ugi‐4CR in the Basic Mediated Tandem Consecutive Cyclization
Chih‐Yu Wu, Sivan Perumal Murugan, Yuwei Wang, Hao‐Wei Pan, Bing‐Jian Sun, Yu‐Ting Lin, Siti Fatimah, Agnes H. H. Chang, Chinpiao Chen, Gene‐Hsian Lee
Abstract
Abstract This study has developed a method to prepare diastereo‐ and regio‐selective indoline‐fused 2,5‐diketopiperazine scaffolds. The synthetic process involved an Ugi four‐component reaction in which readily available starting materials were used and a metal‐free intramolecular post‐Ugi tandem consecutive 5‐exo‐trig / 6‐exo‐dig cyclization under basic conditions. The plausible mechanism and substrate structures were elucidated by single‐crystal X‐ray diffraction analysis and supported by density functional theory calculations. magnified image
Topics & Concepts
ChemistryTandemIndolineIntramolecular forceStereochemistryCascade reactionUgi reactionCombinatorial chemistrySubstrate (aquarium)Organic chemistryIsocyanideCatalysisOceanographyMaterials scienceGeologyComposite materialMulticomponent Synthesis of HeterocyclesMicrobial Natural Products and BiosynthesisChemical Synthesis and Analysis