Chiral Phosphoric Acid‐Catalyzed Enantioselective Three‐Component Povarov Reaction Using Cyclic Enethioureas as Dienophiles: Stereocontrolled Access to Enantioenriched Hexahydropyrroloquinolines

Abstract

Three become one: Phosphoric acid-catalyzed enantioselective three-component Povarov reactions of aldehydes, anilines, and endocyclic enethioureas have been developed (see scheme). This process afforded hexahydropyrroloquinolines in high yields with excellent diastereo- and enantioselectivities. The presence of the thiourea functionality is crucial for the enantioselectivity of the reaction.

Highly Cytotoxic Bioconjugated Gold(I) Complexes with Cysteine‐Containing Dipeptides

“…Recently, we described that chiral phosphoric acids were efficient catalysts for the asymmetric IEDADA reaction of N‐arylimines ( 1 ) and enecarbamates ( 2 ) as dienophiles in a highly diastereo‐ and enantioselective manner (Scheme ) 10b,f,g. A study of the mechanism indicated that the simultaneous dual activation through hydrogen‐bonding interactions of the bifunctional phosphoric acid with both 1 and the NH donor group of 2 was critical for achieving high enantioselectivity 11–13.…”

Nickel‐Based Anode with Water Storage Capability to Mitigate Carbon Deposition for Direct Ethanol Solid Oxide Fuel Cells

“…We recently described the first examples of three‐component enantioselective Povarov reaction of aldehydes ( 2 ), anilines ( 3 ), and enecarbamates 4 (Scheme ) leading to the rapid and efficient generation of a range of 4‐amino‐1,2,3,4‐tetrahydroquinolines 1 6a,d,f. As a continuation of this research program, we wanted to extend this transformation to amino‐substituted aromatic substrates other than anilines.…”

One‐Pot Organocatalytic Enantioselective Michael/Povarov Domino Strategy for the Construction of Spirooctahydroacridine‐3,3′‐oxindole Scaffolds

“… The simultaneous creation of four new chemical bonds (three carbon–carbon bonds and one carbon–nitrogen bond) and five stereocenters including a spiro quaternary center in one‐pot. Less reactive styrene‐type substrates as the olefin component in the Povarov reaction (only three examples of an asymmetric catalytic protocol involving styrene derivatives as the dienophiles in Povarov reaction have been reported11c, 12m,j). The control of diastereo‐ and enantioselectivity of the products. …”

“…Less reactive styrene‐type substrates as the olefin component in the Povarov reaction (only three examples of an asymmetric catalytic protocol involving styrene derivatives as the dienophiles in Povarov reaction have been reported11c, 12m,j).…”