A nitroolefin functionalized BODIPY chemodosimeter for biothiols driven by an unexpected conjugated addition mechanism

A weakly fluorescent nitroolefin functionalized BODIPY 1 was prepared and rapidly reacted with thiols through an unexpected conjugated addition to the azafulvene ring of BODIPY to generate highly fluorescent BODIPYs 4 and 5. This reaction was applied for the highly selective and sensitive detection of Cys in living cells.