Evidence of an nN(amide) → π*Ar Interaction in N-Alkyl-N,N′-diacylhydrazines

1,2-Dibenzoyl-1-tert-butylhydrazine (RH-5849) and related N-alkyl-N,N'-diacylhydrazines are environmentally benign insect growth regulators. In this work, we show that an unusual nN(amide) → π*Ar interaction mediated by a hydrazide amide nitrogen atom plays a crucial role in stabilizing their biologically active trans-cis (t-c) rotameric conformations. We provide NMR and IR spectroscopic evidence for the presence of these interactions, which is also supported by X-ray crystallographic and computational studies.

This work was recently published in Organic Letters (Org. Lett.  2021,  https://doi.org/10.1021/acs.orglett.1c00834.)