Reaction Discovery Using Spectroscopic Insights from an Enzymatic C-H Amination Intermediate

Area of Science:

• Biochemistry
• Synthetic Chemistry
• Biocatalysis

Background:

• Engineered hemoproteins catalyze nitrogen incorporation from precursors.
• Iron-nitrenoids are proposed intermediates but are difficult to characterize.
• Understanding reactive intermediates is key to developing new catalytic methods.

Purpose of the Study:

• To characterize reactive intermediates in hemoprotein-catalyzed nitrogen incorporation.
• To discover new nitrogen-group transfer reagents and catalytic pathways.
• To explore sustainable C-H amination using biological nitrogen cycle components.

Main Methods:

• Utilized UV-vis spectroscopy, electron paramagnetic resonance (EPR), and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS).
• Investigated nitrogen transfer from hydroxylamine in a protoglobin active site.
• Proposed a catalytic cycle for C-H amination.

Main Results:

• Characterized an iron-nitrosyl intermediate formed from hydroxylamine.
• Identified nitrite, nitric oxide, and nitroxyl as novel aminating reagents.
• Demonstrated C-H amination catalysis inspired by the nitrite reductase pathway.

Conclusions:

• Engineered hemoproteins can utilize diverse nitrogen sources for chemical synthesis.
• The study provides new mechanistic insights into nitrogen-group transfer.
• This work opens new avenues for biocatalysis using biological nitrogen cycle intermediates.