for the following products
2-(2,5-Dioxopyrrolidin-1-yl)-1,1,3,3-tetramethylisouronium tetrafluoroborate | N,N,N’,N’-Tetramethyl-O-(succinimidyl)uronium tetrafluoroborate | o-(N-Succinimido)-N,N,N',N'-tetramethyluronium tetrafluoroborate | O-(N-Succinimidyl)-1,1,3,3-tetramethyluronium tetrafluoroborate and TSTU
