Our newest contribution to the field of enzymatic nitrogen-nitrogen bond formation was recently published in ACS Catalysis. In this study, we demonstrate that PZSs are able to catalyze the conversion of various N-hydroxylated diamines, which are different from the natural substrate. The N-hydroxylated diamines were obtained in situ using N-hydroxylating monooxygenases (NMOs), allowing subsequent cyclization by PZS, ultimately forming the N–N bond to yield various N–N bond-containing heterocycles. Using bioinformatic tools, we identified NMO and PZS homologues that exhibit distinct activity and stereoselectivity profiles. The screened panel yielded 17 hydroxylated diamines and more promiscuous NMOs, thereby expanding the substrate range of NMOs, resulting in the formation of previously poorly accessible N-hydroxylated products as substrates for PZS. The investigated PZSs led to a series of 5- and 6-membered cyclic hydrazines, and the most promiscuous catalysts were used to scale up and optimize the synthesis, yielding the desired N–N bond-containing heterocycles with up to 45% isolated yield. 

Today we celebrated the publication of the paper in ACS Catalysis, of course with the most delicious N-N cookies and cake!

Li, Y.; Osipyan, A.; Kok, N. A. W. De; Der, S. S.; Founti, M.; Fodran, P.; Merkerk, R. Van; Maier, A.; Tischler, D.; Schmidt, S. Access to Nitrogen − Nitrogen Bond-Containing Heterocycles Through Substrate Promiscuity of Piperazate Synthases. ACS Catal. 2025. https://doi.org/10.1021/acscatal.5c01237.