The asymmetricconjugateaddition of nitroalkanes to α,β-unsaturated ketones in the presence of a catalytic amount of a novel sulfonamide–thiourea organocatalyst resulted in the corresponding γ-nitro carbonyl products in high yields with excellent enantioselectivities (up to 97% ee).
Asymmetric direct vinylogous aldolreactions of furan-2(5H)-one with aldehydes in the presence of a catalytic amount of novel squaramide–sulfonamide organocatalyst resulted in the corresponding addition products with high to excellent enantioselectivities. This is the first successful report illustrating an example of highly stereoselective reactions using a squaramide–sulfonamide organocatalyst.