Hydride-Induced Novel Cyclization of Dienedinitriles Leading to Multifunctionalized Cyclopentadienes

By treatment with LiAlH4, 1,4-dicyano-1,4-bis(trimethylsilyl)-1,3-dienes underwent a novel hydride-induced nucleophilic intermolecular 1,4-addition to the α,β-unsaturated nitrile moiety, followed by an immediate nucleophilic intramolecular 1,2-addition to the remaining CN group, to afford multiply functionalized cyclopentadienes in high isolated yields. These multifunctional (−CN, −NH2, −SiMe3, −H) cyclopentadienes are of a rich and interesting reaction chemistry as preliminarily demonstrated by their reaction with ArNCO involving both the substituent and the ring.