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. Herein, we show that an unusual n(N)(amide) -> pi*(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.

Automated summary

1,2-Dibenzoyl-1-tert-butylhydrazine and related N-alkyl-N,N'-diacylhydrazines are environmentally friendly insect growth regulators. The interactions mediated by a hydrazide amide nitrogen atom play a crucial role in stabilizing their biologically active trans-cis rotameric conformations, as supported by spectroscopic and computational studies.