References:

1. Yixin Xie, dissertation University of Delaware, THE DIRECT SYNTHESIS OF TETRAZINES FROM CARBOXYLIC ESTER PRECURSORS AND THE DEVELOPMENT OF THE PHOTOCATALYTIC TETRAZINE LIGATION FOR INTRACELLULAR BIOORTHOGONAL LABELING AND UNCAGING.

2. Bioconjugate Chem. 2013, 24, 7, 1210–1217, https://doi.org/10.1021/bc400153y

3. Chem. Sci., 2014,5, 3770-3776, https://doi.org/10.1039/C4SC01348D