Benzotetramisole catalyzed kinetic resolution of 2H-azirines.

An unprecedented benzotetramisole (BTM)-catalyzed kinetic resolution for the efficient synthesis of chiral 2H-azirines is described. This protocol provides two chiral isomers in one step with broad scope, good yield and high enantioselectivity. In addition, the optically pure 2H-azirine products have proven to be useful building blocks for further synthetic transformations.

NHC-Catalyzed Asymmetric α-Regioselective [4 + 2] Annulation to Construct α-Alkylidene-δ-lactones.

The unprecedented NHC-catalyzed [4 + 2] annulation of α-bromoenals with dioxopyrrolidines is described. This protocol features broad substrate scope and allows rapid assembly of α-alkylidene-δ-lactones in good to high yields with excellent enantioselectivities. Notably, this process includes α-regioselective activation of azolium dienolate intermediates, which has not yet been reported.

Synthesis of 3-Azabicyclo[m.2.0] Ring Systems via a Copper-Catalyzed Cascade Reaction of Diazo Compounds with 1,n-Allenynes.

A copper-catalyzed cascade reaction of diazo compounds with 1,n-allenynes (n = 6,7) was reported, which provides efficient access to various functionalized 3-azabicyclo[m.2.0] frameworks (m = 5,6) in moderate to excellent yields under mild reaction conditions. The reaction proceeds through intermolecular cross-coupling to form bisallene intermediates, followed by subsequent intramolecular [2+2] cycloaddition.