Marriage of Peroxides and Nitrogen Heterocycles: Selective Three-Component Assembly, Peroxide-Preserving Rearrangement, and Stereoelectronic Source of Unusual Stability of Bridged Azaozonides
Marriage of Peroxides and Nitrogen Heterocycles: Selective Three-Component Assembly, Peroxide-Preserving Rearrangement, and Stereoelectronic Source of Unusual Stability of Bridged Azaozonides
复制标题
DOI：
10.1021/jacs.1c02249
复制
发表时间：
2021-04-20
影响因子：
15
通讯作者：
Terent'ev，Alexander O.
中科院分区：
文献类型：
--
作者：
Yaremenko，Ivan A.;Belyakova，Yulia Yu;Terent'ev，Alexander O.
通过1,5-二酮、过氧化氢和nhh基团源（如水氨或铵盐）的无催化剂三组分缩合，可以选择性地组装稳定的桥接偶氮腙。这一过程是可扩展的，可以产生克数量的双环立体化学丰富的杂环。新的偶氮腙具有热稳定性，可在室温下保存数月而不分解，在- 10°C下保存至少1年。偶氮腙的化学稳定性被探讨为其随后的选择性转化，包括氨基过氧化物重排保留过氧化物基团的第一个例子。氨基过氧化物中的氨基亲核性很低，不参与通常的胺烷基化和酰化反应。与典型的二烷基胺相比，碱度降低了15个单位，这是由于n→σ* C-O与两个反周面C-O键的强超共轭相互作用。由于互补的nO→σ* c - n从过氧化物中赠送的弱点（“逆α-效应”的结果），这种相互作用消耗了NH部分的电子密度，保护它不被氧化，并使它在性质上类似于酰胺。
Stable bridged azaozonides can be selectively assembled via a catalyst-free three-component condensation of 1,5-diketones, hydrogen peroxide, and an NH-group source such as aqueous ammonia or ammonium salts. This procedure is scalable and can produce gram quantities of bicyclic stereochemically rich heterocycles. The new azaozonides are thermally stable and can be stored at room temperature for several months without decomposition and for at least 1 year at −10 °C. The chemical stability of azaozonides was explored for their subsequent selective transformations including the first example of an aminoperoxide rearrangement that preserves the peroxide group. The amino group in aminoperoxides has remarkably low nucleophilicity and does not participate in the usual amine alkylation and acylation reactions. These observations and the 15 pKaunits decrease in basicity in comparison with a typical dialkyl amine are attributed to the strong hyperconjugative nN→σ*C–Ointeraction with the two antiperiplanar C–O bonds. Due to the weakness of the complementary nO→σ*C–Ndonation from the peroxide oxygens (a consequence of “inverse α-effect”), this interaction depletes electron density from the NH moiety, protects it from oxidation, and makes it similar in properties to an amide.