Practical Synthetic Approach to Chiral Sulfonimides (CSIs) – Chiral Brønsted Acids for Organocatalysis

A general approach to the synthesis of optically pure 3,3′-diaryl chiral sulfonimides (CSIs) from racemic BINOL has been developed. ortho-Lithiation is directed by the sulfonyl groups, and the resulting dihalides serve as the common precursors for the aryl-substituted CSIs.