Hydrogen-bond-donor catalysts enable a variety of formal insertion reactions of diazo
compounds. The role of the catalyst in the reaction system may vary depending on several
factors, including the nucleophilicity of the diazo compound and the acidity of the
insertion partner. Ureas and phosphoric acid derivatives can offer complementary reactivity
patterns when selected as catalysts for selected O–H and S–H insertion reactions of
aryl- and diazo-substituted esters.
Key words
diazo compounds - substituent effects - homogeneous catalysis - insertion reactions
- urea catalysts - phosphate catalysts