“…Recently, Dong, Lei and Wei's group established a sustainable and practical cyclization/hydrolysis of 1,5-enenitriles with sulfonyl hydrazides to access valuable pyrrolidine-2,4-diones in the presence of I 2 and TBHP (Scheme 16). 37 It is worth mentioning that this protocol used water as the green medium and did not need metal catalysts. In the system of I 2 /TBHP, the process starts from the breaking of the N–S bond of sulfonyl hydrazide to produce the sulfonyl radical, which is further selectively added to the CC bond of 1,5-enenitrile to offer the alkyl radical intermediate.…”