Studies on the asymmetric,phosphine-promoted [3+2] annulations of allenic esters with 2-aryl-1,1-dicyanoalkenes

The first enantioselective variant of the phosphine-promoted 3+2] cycloaddition reaction between allenoates and 2-aryl-1,1-dicyanoethylenes has been developed. The use of (S)-t-butyl-Binepine as the chiral organocatalyst allows the synthesis of functionalized cyclopentenes with both aryl and heteroaryl substituents on the stereogenic carbon, in high yields and ees of up to 95%.