New Multicomponent Approach for the Creation of Chiral Quaternary Centers in the Carbonyl Allylation Reactions

The combined regio- and stereo-controlled carbometalation reaction of alkynyl sulfoxide followed
by a zinc homologation and finally an allylation reaction led, in a single-pot operation, to chiral homoallylic
alcohols in excellent yields and diastereoselectivities for the creation of chiral quaternary and tertiary centers.
The key features in all of the reactions that are described in this article are the high degree of stereocontrol,
the level of predictability, and “the ease of execution” which ensures success in the application of such
methods. The chiral sulfinyl moiety can be finally removed by simple treatment with alkyllithiums, which
allows further functionalizations of the carbon skeleton. By using one of these methods, the creation of
chiral quaternary centers with the smallest possible difference, namely CD3 versus CH3 and 13CH3 versus
CH3, was easily performed.