Atom-economical synthesis of the functionalized spirocyclic oxindole-butenolide via three-component [2 + 2 + 1] cycloaddition strategy
作者:Jian Li、Yuejin Liu、Chunju Li、Haohua Jie、Xueshun Jia
DOI:10.1039/c2gc00015f
日期:——
The intermolecular [2 + 2 + 1] multicomponent cycloadditions from readily available isocyanides, activated alkynes and isatins are disclosed. This reaction proceeds by way of a Michael addition–nucleophilic addition–intramolecular cyclization sequence, thus providing new access to spirocyclic oxindole-butenolide with exclusive stereoselectivity in an efficient and atom-economical manner. A broad range of isatins and isocyanides including sterically demanding ones are also found to be compatible with the present protocol, which offers an opportunity for the construction of a new compound library. This protocol also allows the insertion of carbon monoxide into organic molecules without the aid of transition metal catalyst after hydrolysis process. Moreover, the cycloaddition–hydrolysis process by step can be further developed into a practical and powerful one-pot strategy in good yields together with convenient experimental set-up, which adds to its attractiveness.
本发明公开了分子间[2 + 2 + 1]多组分环加成反应,该反应由现成的异氰酸酯、活化炔烃和异汀类化合物组成。该反应通过迈克尔加成-亲核加成-分子内环化的顺序进行,从而以高效和原子经济的方式提供了具有独有立体选择性的螺环氧化吲哚-丁烯内酯的新途径。此外,还发现多种异烷烃和异氰化物(包括对立体选择性要求较高的异烷烃和异氰化物)与本方案兼容,这为构建新的化合物库提供了机会。本方案还允许在水解过程后不借助过渡金属催化剂将一氧化碳插入有机分子中。此外,环加成-水解步骤还可以进一步发展成为一种实用且功能强大的一锅策略,不仅产率高,而且实验设置方便,这也增加了它的吸引力。