Double Functionalization of Atropisomeric Biphenyl Sulfoxides by Ortho ‐Metalation and DYKAT Toward Chiral Quaterphenyl‐Based Borane Lewis Acids

In the young field of enantioselective catalysis by frustrated Lewis pairs, the search for new chiral backbones for Lewis acids is desirable for future developments of the field. By taking advantage of the toluenesulfinyl group, a very useful traceless chiral auxiliary, it was possible to decorate stereopure axially chiral biphenyl tolyl sulfoxides and access unique chiral quaterphenyl tolyl sulfoxides by directed ortho ‐metalation and electrophile trapping as well as a dynamic kinetic asymmetric arylative cross‐coupling. The resulting chiral backbone is amenable to accessing chiral boron‐based Lewis acids by conversion of the sulfinyl group to boron‐based ones.