Heterogeneous Fe-N-C Catalyst for Aerobic Dehydrogenation of Hydrazones to Diazo Compounds Used for Carbene Transfer
Year: 2024
Type: article
Abstract: Organic diazo compounds are versatile reagents in chemical synthesis and would benefit from improved synthetic accessibility, especially for larger scale applications. Here, we report a mild method for the synthesis of diazo compounds from hydrazones using a heterogeneous Fe-N-C catalyst, which has Fe ions dispersed within a graphitic nitrogen-doped carbon support. The reactions proceed readily at room temperature using O 2 (1 atm) as the oxidant. Aryl diazoesters, ketones, and amides are accessible, in addition to less stable diaryl diazo compounds. Initial-rate data show that the Fe-N-C catalyst achieves faster rates than a heterogeneous Pt/C catalyst. The oxidative dehydrogenation of hydrazones may be performed in tandem with Rh-catalyzed enantioselective C–H insertion and cyclopropanation of alkenes, without requiring isolation of the diazo intermediate. This sequence is showcased by using a flow reactor for continuous synthesis of diazo compounds.
DOI: 10.1021/jacs.4c04430
Institutions: University of Wisconsin–Madison, Emory University
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
Awards: G1711593866, G2027168600, New Directions in Enantioselective C-H Functionalization, G222768804, G2320770249, MECHANISMS OF ORGANOMETALLIC COPPER OXIDASES REACTIONS, G4421890870, New Catalysts to Expand the Scope of Donor/Acceptor Carbenes, Acquisition of a 400 MHz NMR Spectrometer for Chemical Research and Learning, G5648016710, Laser-Enhanced NMR Instrumentation for Chemical and Biochemical Research, G614714729, G7119203849, G7730288108, MECHANISMS OF ORGANOMETALLIC AEROBIC OXIDATION REACTIONS CATALYZED BY COPPER, NSF Center for Selective CH Functionalization, QExactive (Orbitrap) mass spectrometer, Catalytic Redox Reactions for Pharmaceutical Synthesis
OpenAlex ID: W4396748713