Synthesis of pyrazoline derivatives from [3 + 2] cycloaddition of Nitrile imine with N-silyl enamine

초록

Enamines showing a variety of applicability for organic synthesis as good nucleophiles, and can be utilized for synthesis of amines,amidines, and other nitrogen containing functional group, showing various application to pharmaceutical chemistry. Our previous studies have focused on the synthesis of cyclic amidines using organic azides with enamine intermediates from the borane-catalyzed hydrosilylation of isoquinolines and quinolines. This study is about construction of pyrazoline ring by using [3 + 2] cycloaddition of the nitrile imine with the N-silyl enamine from the readily available N-heteroarenes.