Ring Expansion of Isatins <i>via</i> 1,2-Phospha-Brook Rearrangement: A Route to the Synthesis of 2-Quinolinone-Derived <i>p</i>-Quinone Methides
Amjad Ali, Harish K. Harit, Manju Devi, Dibyajyoti Ghosh, Ravi P. Singh
Abstract
A Lewis acid-mediated one-carbon homologation approach to installing a 2-quinolinone core embedded with para-quinone methides, in a high yield of up to 92%, and with high regioselectivity has been developed. Also, post-synthetic modifications, including C–P, C–S, and C–C bond formations, have been demonstrated by the 1,6-addition of suitable nucleophiles. Further, cyclopropanation of 2-quinolinone-embedded p-QM is also demonstrated affording a contiguous quaternary spiro center.
Topics & Concepts
ChemistryRegioselectivityCyclopropanationNucleophileRing (chemistry)QuinoneYield (engineering)Lewis acids and basesMedicinal chemistryClaisen rearrangementCombinatorial chemistryStereochemistryOrganic chemistryCatalysisMetallurgyMaterials scienceSynthesis of Indole DerivativesCarbohydrate Chemistry and SynthesisSulfur-Based Synthesis Techniques