Herein, we describe an example of catalytic asymmetric synthesis of sulfinamides. Aromatic
sulfenamides were chosen as useful substrates, because of the indispensable N–H bond,
which could form an efficient hydrogen bond with chiral phosphoric acid. H2O2 (35%) was
used as the terminal oxidant for preparation of sulfinamides in high yields and
enantioselectivities, which could be easily derivatized to sulfoxides and other sulfinamides
without loss of the enantioselectivity.

Significance: In this work, the authors develop a chiral Brønsted acid catalyzed asymmetric
oxidation of sulfenamides by hydrogen peroxide with high atom efficiency. Mechanistic
studies showed that hydrogen peroxide is activated by the chiral phosphoric acid through
hydrogen bonding, and that hydrogen bonding between the catalyst and substrate N–H
might also be critical to the oxidation mechanism. Comment: Decreased yields and
enantioselectivities were obtained with sulfenamides with electron-donating substituents …