First Efficient and General Copper‐Catalyzed [2,3]‐Rearrangement of Tetrahydropyridinium Ylids.

Abstract

The title reaction proceeds via the reaction of diazo esters with N-methyltetrahydropyridines. A range of diazo and amine components has been used to generate a collection of structurally diverse, densely functionalized pyrrolidines in good yields. The nature of the α-substituent in the diazo component has a dramatic effect upon the yields of the reaction: electron-withdrawing substituents enhance the yield. -(ROBERTS, E.; SANCON, J. P.; SWEENEY*, J. B.; WORKMAN, J. A.; Org. Lett. 5 (2003) 25, 4775-4777; Dep. Chem., Univ. Reading, Whiteknights, Reading, Berkshire RG6 6AD, UK; Eng.) -Steudel 16-119

Modern Organic Synthesis with α-Diazocarbonyl Compounds

“…The first efficient and general copper-catalyzed [2,3]sigmatropic rearrangement of tetrahydropyridinium ylides was described in 2003 by Sweeney and co-workers. 592 A large substrate scope was demonstrated in this study, with a range of diazoester and N-methyltetrahydropyridine components found to provide functionalized pyrrolidine products in good to excellent yields (Scheme 256). The nature of the α-substituent of the diazo substrate was found to be particularly important in these transformations, with electron-withdrawing substituents found to enhance product yields.…”