A bioorthogonal molecule can include a molecule having a structure according the above wherein R1-R8 are independently selected from H, a substituted or unsubstituted C1-C4 alkyl or alkylene group, COOH, COOR9, COR9, CONR9R10, CN, CF3, and SO2R9, and where R9 and R10 are independently selected from H and a substituted or unsubstituted C1-C4 alkyl or alkylene group, with the proviso that one of R3-R8 comprises a leaving group, and wherein X is O, S, N, SO, SO2, SR+, Se, PO2−；, or NRR′；+, and where R and R′； are independently selected from H or a substituted or unsubstituted C1-C4 alkyl or alkylene group.
