Paradigms and Paradoxes: Diazomethane and Ethyl Diazoacetate: The Role of Substituent Effects on Stability

摘要: Diazomethane and ethyl diazoacetate are highly reactive versatile synthetic reagents that undergo numerous related reactions. However, while the former is dangerous because of its toxicity explosive behavior; latter much more benign. This usually ascribed to resonance stabilization in involving an extra carbonyl group absent diazomethane, cf. $$\begin{gathered} {\text{EtOOC}}---{\text{CH}} = {\rm N}^ + - \leftrightarrow E}{\text{tOOC}}---{\text{CH}}^ ---{\text{N}}^{\text{ }} \equiv {\text{N}} {\text{EtOC(O}}^ {\text{)}} {\text{CH}}---{\text{N}}^{\text{ N} \hfill \\ {\text{CH}}_{\text{2}} {\text{CH}}_{\text{2}}^ \end{gathered}$$ The additional derived using a recent literature measurement enthalpy diazoacetate/aldehyde reaction, key enthalpies formation, also from literature, some simplifying assumptions. The deduced be but 16 kJ/mol, merely 4 kcal/mol. But, oh how grateful we for this!