Stereoselective C(sp2)-H Alkylation of Enamides with Unactivated Aliphatic Carboxylic Acids via Decarboxylative Cross-Coupling Reactions.

An efficient and straightforward stereoselective alkylation reaction of enamides using commercially available and easily accessible unactivated alkyl carboxylic acids as alkylating agents is described, giving rise to a diverse array of synthetically important and geometrically defined ß-alkylated enamides bearing primary, secondary, or tertiary alkyl moieties. This transformation also shows excellent functional group tolerance, satisfying atom economy, and operational simplicity.

Regioselective and Stereoselective Difluoromethylation of Enamides with Difluoromethyltriphenylphosphonium Bromide via Photoredox Catalysis.

A regioselective and stereoselective difluoromethylation of enamides with bench-stable and easily accessible difluoromethyltriphenylphosphonium bromide is described. A broad array of synthetically important and geometrically defined ß-difluoromethylated enamides bearing various functional groups are obtained with up to 91% yield.

Enantioselective Direct α-Arylation of Pyrazol-5-ones with 2-Indolylmethanols via Organo-Metal Cooperative Catalysis.

The first catalytic asymmetric α-arylation of pyrazol-5-ones has been established by using 2-indolylmethanols as direct electrophilic arylation reagents under the cooperative catalysis of Pd(0) and a chiral phosphoric acid, which afforded the α-arylation products of pyrazol-5-ones in generally high yields and good enantioselectivities (up to 99% yield, >99% ee).

Application of 3-Methyl-2-vinylindoles in Catalytic Asymmetric Povarov Reaction: Diastereo- and Enantioselective Synthesis of Indole-Derived Tetrahydroquinolines.

The first application of 3-methyl-2-vinylindoles in catalytic asymmetric Povarov reactions has been established via the three-component reactions of 3-methyl-2-vinylindoles, aldehydes, and anilines in the presence of chiral phosphoric acid, providing easy access to chiral indole-derived tetrahydroquinolines with three contiguous stereogenic centers at high yields (up to 99%) and with excellent diastereo- and enantioselectivities (all >95:5 dr, up to 96% ee). This mode of catalytic asymmetric three-component reaction offers a step-economic and atom-economic strategy for accessing enantioenriched indole-derived tetrahydroquinolines with structural diversity and complexity.