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An Azide-Free Synthesis of Metallodiazomethanes Using Nitrous Oxide

Year: 2024

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Diazo compounds are valuable reagents in synthesis but usually require the use of potentially explosive or toxic starting materials. Here, we report the synthesis and isolation of alkali metal diazomethanides by the reaction of metalated ylides with nitrous oxide, resulting in a formal exchange of the phosphine ligand by dinitrogen. The reaction proceeds through a Wittig-like mechanism via a [3 + 2] cycloaddition of N 2 O across the ylide bond with release of phosphine oxide. The metalated diazomethanes exhibit an increased thermal stability due to the stronger binding of N 2 compared to neutral diazomethanes. This is reflected in short C–N distances and red-shifted N–N vibrations and enables versatile applications such as for the preparation of transition metal diazomethanide complexes and the synthesis of 1,2,3-triazoles from nitriles, diazoacetates from carbon dioxide, or alkynes from aldehydes.

Source: Journal of the American Chemical Society

DOI: 10.1021/jacs.4c07999