Morita-Baylis-Hillman Reaction of β,β-Disubstituted Enones: An Enantioselective Organocatalytic Approach for the Synthesis of Cyclopenta[b]annulated Arenes and Heteroarenes.

摘要: The first enantioselective organocatalytic intramolecular Morita-Baylis-Hillman (MBH) reaction of sterically highly demanding β,β-disubstituted enones is presented. MBH β,β-disubstituted-α,β-unsaturated electron-withdrawing systems was previously considered to be unfeasible. Towards this end, designer substrates, which under simple and practical conditions generate a variety cyclopenta[b]annulated arenes heteroarenes in excellent enantiopurities near-quantitative yields remarkably short times, are described. reason for the unusually facile nature attributed synergy guided entropically favored reaction. Further, strategy provides easy access substantial number bioactive natural products pharmaceutically significant compounds.