Wender Paul A, Pedersen Torben M, Scanio Marc J C
Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
J Am Chem Soc. 2002 Dec 25;124(51):15154-5. doi: 10.1021/ja0285013.
The first example of a transition metal-catalyzed hetero-[5 + 2] cycloaddition reaction is described. Use of cyclopropyl imines as five-atom components, an alkyne as a two-carbon component, and a Rh(I) catalyst enables a new route to dihydroazepines. This new hetero-[5 + 2] cycloaddition works well with aldimines, ketimines, and with substituted cyclopropanes and affords the desired dihydroazepines in excellent yields as single regioisomers. Use of serial imine formation/aza-[5 + 2] cycloaddition generates the desired dihydroazepines in one operation from three commercially available starting materials. The reaction has been scaled to give gram quantities of dihydroazepine.
描述了过渡金属催化的杂-[5 + 2]环加成反应的首个实例。使用环丙基亚胺作为五原子组分、炔烃作为二碳组分以及Rh(I)催化剂，可开辟一条合成二氢氮杂卓的新途径。这种新的杂-[5 + 2]环加成反应与醛亚胺、酮亚胺以及取代环丙烷都能很好地反应，并以优异的产率得到所需的二氢氮杂卓单一区域异构体。通过连续的亚胺形成/氮杂-[5 + 2]环加成反应，可从三种市售起始原料一步合成所需的二氢氮杂卓。该反应已放大至克级规模以制备二氢氮杂卓。
