Hindered ester formation by S<sub>N</sub>2 azidation of N-acetoxy-N-alkoxyamides and N-alkoxy-N-chloroamides—novel application of HERON rearrangements
作者:Stephen A. Glover、Guoning Mo
DOI:10.1039/b111250n
日期:——
Treatment of N-acetoxy-N-alkoxyamides or N-alkoxy-N-chloroamides with sodium azide in aqueous acetonitrile results in SN2 displacement of chloride and the formation of reactive N-alkoxy-N-azidoamides. The reaction with N-acetoxy-N-benzyloxybenzamide has been studied kinetically (k294
= 2 L molâ1 sâ1) and azidation of N-formyloxy-N-methoxyformamide has been modeled computationally at the pBP/DN*//HF/6-31G* level of theory. The anomeric amides N-alkoxy-N-azidoamides decompose intramolecularly and spontaneously to esters and two equivalents of nitrogen. This extremely exothermic process facilitates the formation, in excellent yields, of highly hindered esters.
在水合乙腈中,N-乙酸氧基-N-烷氧基酰胺或N-烷氧基-N-氯酰胺与叠氮化钠反应会导致氯的SN2取代,并形成反应性N-烷氧基-N-叠氮酰胺。对N-乙酸氧基-N-苄氧基苯甲酰胺的反应动力学进行了研究(k294 = 2 L mol⁻¹ s⁻¹),并在pBP/DN*//HF/6-31G*理论水平上对N-甲酸氧基-N-甲氧基甲酰胺的叠氮化反应进行了计算模拟。异头酰胺N-烷氧基-N-叠氮酰胺会自发地发生分子内分解,生成酯和两分子氮气。这一极放热过程促进了高阻碍酯的高产率形成。