Diastereoselective synthesis of C3 quaternary indolenines using a,b unsaturated N aryl ketonitrones and activated alkynes.
Indole containing structures are ubiquitous in natural products, medicinal compounds, and organic materials. Given their biomedical importance, synthetic methods towards these structural motifs remain relevant even after decades of innovations. However, despite all the efforts toward the efficient construction of C3 quaternary indole derivatives, significant challenges remain. These challenges are found in the forms of spirooxindole, pyrroloindoline, furoindoline, and other indole containing polycycles, which exist in a large number of alkaloids, such as physovenine, physostigmine, minfiensine, citrinadin B, communesin B, aspidophylline A, and mitraphylline (Scheme 1) Many of the
Angewandte Chemie