A simple and efficient copper-catalyzed three-component reaction to synthesize ()-1,2-dihydro-2-iminoquinolines.

A operationally simple synthesis of ()-1,2-dihydro-2-iminoquinolines that proceeds under mild conditions is achieved by copper-catalyzed reaction of 1-(2-aminophenyl)ethan-1-ones, sulfonyl azides and terminal ynones. In particular, the reaction goes through a base-free CuAAC/ring-opening process to obtain the -configured products due to hydrogen bonding.

Organocatalytic Regiodivergent Ring Expansion of Cyclobutanones for the Enantioselective Synthesis of Azepino[1,2-]indoles and Cyclohepta[]indoles.

A regiodivergent organocatalytic enantioselective Michael addition/three-atom ring expansion sequence of electron-withdrawing group activated cyclobutanones with 2-nitrovinylindoles was developed. A series of azepino[1,2-]indoles were obtained with exclusive regioselectivities and high diastereo- and enantioselectivities (up to >20:1 dr, 96% ee) with the application of the N1 nucleophilic site of the indole nucleus. Meanwhile, various cyclohepta[]indoles could be accessed with high enantiopurity (up to 96% ee) through the Michael addition/boron-trifluoride-etherate-promoted indole C3-attack ring expansion process.

Enantioselective Construction of CF-Containing Spirooxindole γ-Lactones via Organocatalytic Asymmetric Michael/Lactonization.

A highly enantioselective Michael/lactonization cascade reaction of 3-hydroxyoxindoles with 3-trifluoroethylidene oxindoles was developed. The use of a cinchona-derived squaramide catalyst is essential in achieving high diastereo- and enantioselectivities. This reaction represents the first example of intramolecular amide C-N bond cleavage and lactonization of 3-hydroxyoxindoles with 3-trifluoroethylidene oxindoles, which provides an efficient and convenient approach to diverse CF-containing spirooxindole γ-lactones in high yields and good to excellent diastereo- and enantioselectivities.

Asymmetric Synthesis of 3,4-Dihydroquinolin-2-ones via a Stereoselective Palladium-Catalyzed Decarboxylative [4 + 2]- Cycloaddition.

An efficient, palladium-catalyzed, decarboxylative [4 + 2]-cycloaddition of 4-vinyl benzoxazinanones with carboxylic acids has been developed with the employment of P-chiral monophosphorus ligand BI-DIME, affording a series of structurally diverse 3,4-dihydroquinolin-2-ones bearing two contiguous stereogenic centers in moderate to good yields with good to excellent stereoselectivities.