K2CO3-Generated Azomethine Ylides and Highly Regioselective (3 + 2)-Cycloaddition to Functionalized
Debasish Ghosh1, Sabir A Molla1, Shobhon Aich1
1Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata 700009, India.
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The K2CO3-mediated synthesis of frequently used azomethine ylide intermediates and their highly regioselective 1,3-dipolar cycloaddition reactions are elegantly demonstrated, offering a regiocontrolled synthesis of valuable fused N-heterocycles. These relatively stable azomethine ylides undergo dual C-C and C-N coupled cyclization with terminal alkynes and N-substituted maleimides under metal-free conditions, providing a concise and aesthetically pleasing route to functionalized 2,3-dihydro-1H-pyrrolizines. The detection of intermediates and density functional theory (DFT) calculations confirm the regio- and stereoselectivity of this cycloaddition process, highlighting its precision and efficiency.
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