Organocatalyzed Assembly of Chlorinated Quaternary Stereogenic Centers.

The catalytic asymmetric construction of chiral quaternary stereocenters is a continual area of research for organic chemists. In this sense, when a chlorine atom is introduced to a quaternary stereocenter, the synthetic difficulty of the resulting molecule increases along with its significance. This is true not only because of the intrinsic interest in such chlorinated molecules but also because they are highly valuable chiral building blocks in organic synthesis, as they can be converted into more complex molecules by a S_N2 displacement reaction. Among the different strategies to create chlorinated quaternary stereogenic centers, organocatalysis has played a pivotal role over the past decade. In this review, a comprehensive analysis of such organocatalyzed transformations with a focus on the a-chlorination of carbonyl compounds is presented. [ABSTRACT FROM AUTHOR]