Fe-Catalyzed Allylic C-C-Bond Activation: Vinylcyclopropanes As Versatile a1,a3,d5-Synthons in Traceless Allylic Substitutions and [3+2]-Cycloadditions

The low-valent iron complex Bu4N[Fe-(CO)(3)(NO)] (TBAFe) catalyzes the allylic C-C-bond activation of electron-poor vinyl cyclopropanes to generate synthetically useful a1,a3,d5-synthons which are prone to undergo multiple consecutive reactions. The versatility of this approach is demonstrated by a traceless allylic substitution and a formal [3 + 2] cycloaddition to give either functionalized acyclic products or densely substituted cyclopentanes and pyrrolidines in high yields and regioselectivities.