Construction of Vicinal Tetrasubstituted Stereocenters with a C–F Bond through a Catalytic Enantioselective Detrifluoroacetylative Mannich Reaction

An efficient asymmetric detrifluoroacetylative Mannich reaction of 2-fluoro-1,3-diketones/hydrates with isatin-derived ketimines catalyzed by a chiral copper­(II)-diamine complex has been realized. The reaction afforded a series of 3-substituted 3-amino-2-oxindoles bearing fluorine-containing vicinal tetrasubstituted stereocenters in high yields (up to 99%) with excellent diastereoselectivities (up to >20:1 dr) and enantioselectivities (up to 94% ee)

Catalytic Asymmetric [3 + 2] Cyclization Reactions of 3‑Isothiocyanato Oxindoles and Alkynyl Ketones Via an in Situ Generated Magnesium Catalyst

A highly enantioselective formal [3 + 2] cycloaddition reaction between 3-isothiocyanato oxindoles and alkynyl ketones is reported for the first time. An oxazoline–OH type chiral ligand derived from <i>o</i>-hydroxy-phenylacetic acid is employed to generate an effective magnesium catalyst in the current cyclization reaction and give serials of chiral spirooxindoles with good chemical yields and enantioselectivities

Transition-Metal-Free Dehydrosilylative Difluoroamidation of Tetrahydroisoquinolines under Mild Conditions

Disclosed herein is a dehydrosilylative difluoroamidation of α-Csp³–H of tetrahydroisoquinolines with α,α-difluoro-α-TMS-acetamides. The process, which occurs at ambient temperature in the absence of any transition metals, provides direct access to a broad range of α,α-difluoroacetamide-substituted tertiary amine derivatives in high yields. Moreover, the method was successfully applied in the Csp³–H-directed difluorophosphorylation and difluorocarboxylation under the same conditions

Development of Biligands Magnesium Catalysis in Asymmetric Conjugate Reactions of C3-Pyrrolyl-Oxindoles

A magnesium catalyzed asymmetric conjugate reaction of C3-pyrrolyl-oxindoles with terminal alkynones is presented. The current asymmetric conjugate reaction relies on the development of novel combinational magnesium catalysis involving two chiral ligands. The current protocol proceeds smoothly and gives the corresponding enantioenriched 3,3-disubstituted oxindole skeletons with good enantioselectivities. Furthermore, the conjugate adducts could be transferred to spiro oxindole structures containing an eight-membered ring in high ee values