The general synthesis, isolation and characterization of electrophilic iodine reagents of the general formula R4N[I(O2CAr)2] is reported. These compounds are air‐ and moisture‐stable iodine(I) reagents, which were characterized including X‐ray analysis. They represent conceptually new iodine(I) reagents with anions as stabilizers. These compounds display the expected performance as electrophilic reagents upon interaction with electron‐rich substrates. The performance of these compounds in a total of 47 different reactions of vicinal iodooxygenation of alkenes is studied and some key features on the reagents are revealed.