The intermolecular [2 + 2] cycloaddition/isomerization between allenyl imides and N-(2-methoxyphenyl) aldimine counterparts catalyzed by a Ni­(ClO4)2·6H2O Lewis acid at room temperature was discovered, providing a facile access to 1-azadiene derivatives with high atom economy. The incorporation of an 2-oxazolidinone group into allene amides resulted in unusual reactivity for the imine-metathesis and synthetic application to a chiral γ,δ-unsaturated β-ketoimide. A mechanistic experiment using density functional theory (DFT) computation in CH2Cl2 with the B3LYP functional rationalized the proposed catalytic pathway involving initial stepwise [2 + 2] cycloaddition to provide an azetidine species, two-time proton transfer to form a 2-azetine intermediate, and final conrotatory ring opening for trans-1-azadiene-based substances.

2-Pyridylsulfone- and fluoroalkylated group-activated olefins underwent highly efficient diastereo- and enantioselective 1,3-dipolar cycloadditions across various aromatic and aliphatic nitrones in the presence of a chiral Ni /bis(oxazoline) catalyst. The process was tuned by 4 Å molecular sieves, chiral bis(oxazoline) ligands, reaction solvents, and temperature. A wide array of optically pure fluoroalkylated isoxazolidines were obtained, thus facilitating the asymmetric synthesis of an enantioenriched α-trifluoromethylated γ-amino alcohol in gram-scale and a trifluoromethylated derivative of 1,3-oxazinan-2-one with potential pharmaceutical interest. A stereochemical model, based on the absolute configuration of one adduct and some control experiments, was postulated to account for the observed endo- and enantioselectivity.

The first chiral Brønsted acid-catalyzed asymmetric cascade allylboration/oxo-Michael reaction between o-formyl chalcones and allylboronate has been successfully discovered, which afforded chiral 1,3-disubstituted 1,3-dihydroisobenzofurans with a yield, diastereoselective ratio (dr) and enantioselective excess (ee) up to 94%, 2.5:1, and 98%, respectively. In addition, 2,3-dienylboronic pinacol ester was also applied into this cascade reaction with good catalytic results.

2-Pyridylsulfone-and fluoroalkylated group-activated olefins underwent highly efficient diastereo-and enantioselective 1,3-dipolar cycloadditions across various aromatic and aliphatic nitrones in the presence of ac hiral Ni II / bis(oxazoline) catalyst. The process was tuned by 4 molecular sieves,chiral bis(oxazoline) ligands,reaction solvents,and temperature.Awide arrayo fo ptically pure fluoroalkylated isoxazolidines were obtained, thus facilitating the asymmetric synthesis of an enantioenriched a-trifluoromethylated g-amino alcohol in gram-scale and at rifluoromethylated derivative of 1,3-oxazinan-2-one with potential pharmaceutical interest. A stereochemical model, based on the absolute configuration of one adduct and some control experiments,w as postulated to account for the observed endo-and enantioselectivity.