Recent advances on micellar catalysis in water.

A hemin/H2O2 catalytic system for oxidative phenol–indole [3 + 2] coupling in aqueous solution has been developed, enabling benign synthesis of valuable benzofuroindolines under sustainable conditions. Mechanistic studies revealed the dual role of iron porphyrin responsible for both phenol oxidation and Lewis acid activation, which differs from the well-explored chemistry of hemin in carbene and nitrene insertion reactions. A preliminary experiment with cytochrome c showed that the turnover of iron porphyrin was amenable for a macromolecular setting with remarkable efficiency (ca. 13 300 TON).

Hemin-catalyzed biomimetic oxidative phenol–indole [3 + 2] reactions in aqueous media

Cinchona Alkaloid Derived Iodide Catalyzed Enantioselective Oxidative α-Amination of Carbonyl Compounds toward the Construction of Spiroindolyloxindole.

This article discloses the direct α-amination of α-branched aldehydes applying nitrogen-based nucleophiles. Under organocatalyzed, oxidative conditions α-branched aldehydes are umpoled to their electrophilic synthons and, subsequently, displaced by a variety of nucleophilic amines to form tetrasubstituted tertiary centers. A similar strategy has been previously employed to form congested C-C, C-O, and C-S bonds; however, unsatisfactory results were received when extending the methodology to include C-N bonds. Initially, intramolecular α-amination reactions were undertaken to foster dihydroquinoxaline-type products. A solvent exchange to the polar, aprotic solvent, MeNO2, proved critical to facilitate intermolecular α-C-N bond formation with a wide range of amine coupling partners (N-heterocycles, N,N-diaryl amines, and anilines). Application of the solvent exchange to the enantioselective SN2-DKR manifold provided distinct regimes leading to refinement in yield and enantioselectivity.

Metal-free, Oxidative α-Coupling of Aldehydes with Amine Nucleophiles for the Preparation of Congested C(sp3)-N Bonds.

A highly efficient base-mediated diastereoselective [4+1] cycloaddition of ortho-tosylaminophenyl-substituted p-QMs with 3-chlorooxindoles has been developed to afford 3,2’-pyrrolidinyl spirooxindoles in high yields with high diastereoselectivity through domino 1,6-addition/cyclization sequence. This...

Synthesis of Functionalized 3,2′-Pyrrolidinyl Spirooxindoles via Domino 1,6-Addition/Annulation Reactions of para-Quinone Methides and 3-Chlorooxindoles

Huimin Su

Papers

Unified and Benign Synthesis of Spirooxindoles via Bifunctional and Recyclable Iodide‐Salt‐Catalyzed Oxidative Coupling in Water