Chiral anthranilic pyrrolidine as custom-made amine catalyst for enantioselective Michael reaction of nitroalkenes with carbonyl compounds

Optimizing the Local Chemical Environment on a Bifunctional Helical Peptide Scaffold Enables Enhanced Enantioselectivity and Cooperative Catalysis

We describe a proof-of-concept study in which peptide-bound enamine and thiourea catalysts are used to facilitate the conjugate addition of cyclohexanone to nitroolefins. Our bifunctional peptide scaffold is modified to optimize the local environment around both catalysts to enhance both reactivity and enantioselectivity, affording selectivities of ≤95% ee. Circular dichroism, nuclear magnetic resonance nuclear Overhauser effect studies, and molecular dynamics simulations verify the helical structure of our catalyst in solution and the importance of the secondary structure in catalysis.

Palladium/GF-Phos-catalyzed asymmetric carbenylative amination to access chiral pyrrolidines and piperidines

The cross-coupling of N-tosylhydrazones has emerged as a powerful method for the construction of structurally diverse molecules, but the development of catalytic enantioselective versions still poses considerable challenges and only very limited examples have been reported. We herein report an asymmetric palladium/GF-Phos-catalyzed carbenylative amination reaction of N-tosylhydrazones and (E)-vinyl iodides pendent with amine, which allows facile access to a range of chiral pyrrolidines and piperidines in good yields (45–93%) with up to 96.5 : 3.5 er. Moreover, mild conditions, general substrate scope, scaled-up preparation, as well as the efficient synthesis of natural product (−)-norruspoline are practical features of this method.

An efficient asymmetric palladium/GF-Phos-catalyzed carbenylative amination reaction to access structurally diverse chiral pyrrolidines and piperidines in good yields with high chemo-, regio- and enantioselectivities has been developed.