Base-enabled access to diastereoselective spirofuran oxindoles and γ-functionalized allenoates
D Basavaraja, Ajay Krishna M. S., Jagadeesh Krishnan, C. S. Athira, R. R. Amrutha, Eringathodi Suresh, Sasidhar B. Somappa
Abstract
Base assisted divergent reactivity of isatins and allenoates has been achieved, which afforded diastereoselective spirofuran oxindoles and γ-functionalized allenoates. The DBU mediated Morita-Baylis-Hillman (MBH) reaction followed by the cascade annulation through the stabilized β-ammonium enolate intermediate led to the spiro-framework, wherein DABCO furnished the γ-functionalized allenoates. The protocol offers access to biologically relevant functionalized oxindole scaffolds with an excellent substrate scope under mild reaction conditions.
Topics & Concepts
Base (topology)Reactivity (psychology)Combinatorial chemistryChemistryMathematicsMedicinePathologyMathematical analysisAlternative medicineAsymmetric Synthesis and CatalysisCyclopropane Reaction MechanismsCatalytic C–H Functionalization Methods