Control of axial chirality in absence of transition metals based on arynes

Asymmetric iodine catalysis-mediated enantioselective oxidative transformations

The implementation of chiral iodine catalysis has tremendously been developed in the field of asymmetric synthesis over the past decade. It enables the stereoselective creation of C-O as well as C-C, C-N and C-X (X = halogen) bonds through oxidative transformations. Thanks to the low toxicity and ease of handling of iodine compounds, this strategy offers many advantages over classical metal-catalyzed oxidations with chiral ligands. The approaches rely on iodine(i/iii) or (-i/+i) catalysis by using a chiral aryliodine or ammonium iodide respectively in combination with a suitable terminal oxidant. As such, the design of iodine compounds with central, axial or even planar chirality has allowed us to achieve high enantioselectivities. The goal of this review is to cover the different chiral iodine compound-catalyzed oxidative transformations including α-functionalization of carbonyl compounds, dearomatization of phenol derivatives and difunctionalization of alkenes which should demonstrate that iodine catalysis has now found its place in the realm of asymmetric organocatalysis.