A computational study to unravel the selectivity in an iron-catalysed [3+2] cycloaddition of aziridine and heterocumulenes

作者：Adhikari Debashis^*

来源：RSC Advances, 2015, 5(115): 95379-95384.

DOI：10.1039/c5ra19407e

The reaction mechanism of cycloaddition between phenyl aziridine and heterocumulene catalysed by iron salts in water has been modeled computationally to trace the origin of the excellent regioselectivity toward 5-substituted product formation. The calculations reveal that the Lewis-acidic iron centre activates and increases the electrophilicity of the heterocumulene upon binding, so that a nucleophilic aziridine-attack can be invoked. The preferential opening of the substituted C-2-N bond in the following intermediate, dictated by the stability of an incipient carbocation is the key for such selectivity. Since the aziridine ring-opening step is asynchronous, concerted in nature, the iminoazoselenolidine ring retains the stereopurity at the chiral carbon.

• 出版日期2015