Experimental and theoretical push-pull Chemo- and regioselectivity in 1,3-Dipolar cycloaddition reactions: the case of benzotriazepin-5-one with mesitylnitrile oxide
作者:Saida Azzouzi、Rachid Jalal、Malika El Messaoudi、Luis R. Domingo、M'hamed Esseffar、M. José Aurell
DOI:10.1002/poc.1145
日期:2007.4
11a-tetrahydro-6H-[1,2,4]oxadiazolo [5,4-b][1,3,4]benzotriazépin-6-one 4 has been synthesised by a 1,3 dipolar cycloaddition (13DC) reaction of 1,3,4-benzotriazepin-5-one 1 with mesitylnitrile oxide 3. The reaction, beside its synthetic interest, has shown to be completely chemo- and regioselective. The structure of the compound was determined by X-ray crystallography and analysed by spectral methods (NMR
新型杂环化合物3-甲杂1-5-甲基-4,5,11,11a-四氢-6H- [1,2,4]恶二唑并[5,4-b] [1,3,4]苯并三氮杂-6- 1 4已通过1,3,4-苯并三氮杂-1-酮1 -1与异腈腈3的1,3偶极环加成(13DC)反应合成。该反应除了具有合成意义外,还显示出完全的化学选择性和区域选择性。该化合物的结构通过X射线晶体学测定并通过光谱方法(NMR和质谱法)分析。已使用B3LYP / 6-31G *理论水平的量子力学计算研究了该反应的分子机理。形成环加合物4的两种机理是可能的。第一个涉及13DC之间的反应1为偶极亲子,3为偶极子。结果分析表明,它是沿着极低极性的异步协同键形成过程进行的。从计算中获得的区域选择性与环加合物4的独特形成完全一致。第二种机制是通过互变异构形式2的N3氮对腈氧化物3的C5碳的亲核攻击而引发的,从而产生了mid胺肟。但是,此添加过程中涉及的大量能量阻止了