Highly enantioselective synthesis of gamma-hydroxy-alpha,beta-acetylenic esters catalyzed by a beta-sulfonamide alcohol.

This work concerns the asymmetric addition of methyl propiolate to aldehydes with 1,2-dimethoxyethane (DME) as additive and beta-sulfonamide alcohol titanium complex as a catalyst. The reactions proceeded under mild conditions and gave the highly functionalized chiral propargylic alcohols with high ee values and good yields. Differences between three types of ligands have also been discussed.

Highly enantioselective addition of phenylacetylene to aldehydes catalyzed by a camphorsulfonamide ligand.

The asymmetric addition of phenylacetylene to aldehydes was carried out by using a camphorsulfonamide titanium complex as a catalyst. The reactions proceeded under mild conditions and gave the products with good yields and high ees. This system is very useful for the synthesis of chiral propargylic alcohol.