[4 + 2] cycloadditions of N-alkenyl iminium ions: structurally complex heterocycles from a three-component Diels-Alder reaction sequence.
[4 + 2] cycloadditions of N-alkenyl iminium ions: structurally complex heterocycles from a three-component Diels-Alder reaction sequence.
复制标题
DOI：
10.1021/ja8028153
复制
发表时间：
2008-07
影响因子：
15
通讯作者：
N. Sarkar;Abhisek Banerjee;Scott G Nelson
中科院分区：
文献类型：
--
作者：
N. Sarkar;Abhisek Banerjee;Scott G Nelson
N-烯基亚铵离子可作为三组分[4 + 2]环加成反应的导管，获得结构和立体化学不同的哌啶衍生物。这些阳离子2-氮杂二烯参与与富电子和中性烯烃亲二烯体的内选择性或外选择性[4 + 2]环加成，以生成四氢吡啶离子作为初始环加成物。原位亲核加成衍生的亚胺离子完成了三组分偶联序列，并提供了一个通用的合成结构复杂的哌啶。
N-Alkenyl iminium ions serve as conduits to three-component [4 + 2] cycloaddition reactions accessing structurally and stereochemically diverse piperidine derivatives. These cationic 2-azadienes participate in endo- or exo-selective [4 + 2] cycloadditions with electron-rich and neutral alkene dienophiles to generate a tetrahydropyridinium ion as the initial cycloadduct. In situ nucleophilic addition to the cycloaddition-derived iminium ion completes the three-component coupling sequence and affords a versatile synthesis of structurally complex piperidines.