Palladium-Catalyzed [3 + 3] Cycloaddition of Trimethylenemethane with Azomethine Imines

A palladium-catalyzed [3 + 3] cycloaddition of trimethylenemethane (TMM) with azomethine imines has been developed to produce hexahydropyridazine derivatives under simple and mild conditions. The use of substituted TMM precursors highlights the difference of this system from previously reported [3 + 2] cycloaddition of TMMs under palladium catalysis. The present [3 + 3] cycloaddition reactions are also applicable to couplings with nitrones.

本研究开发了一种钯催化的三亚甲基甲烷（trimethylenemethane, TMM）与甲亚胺亚胺（azomethine imines）的[3+3]环加成反应，可在温和简便的反应条件下合成六氢哒嗪衍生物。相较于此前报道的钯催化TMM参与的[3+2]环加成反应，该体系采用取代型TMM前体，凸显了二者的反应特性差异。此外，本次开发的[3+3]环加成反应同样适用于与硝酮（nitrones）的偶联反应。