A Synthetic Methodology to Niobium Alkylidenes: Reactivity of a NbNb Double Bond Anchored to a Calix[4]arene Oxo Surface with Ketones, Aldehydes, Imines, and Isocyanides
作者:Alessandro Caselli、Euro Solari、Rosario Scopelliti、Carlo Floriani
DOI:10.1021/ja990647n
日期:1999.9.1
compound leading to the synthesis of niobium alkylidenes and niobium alkylidynes from ketones and aldehydes is a [NbIIINbIII] dimer, [p-But-calix[4]-(O)4}2Nb2Na2] (3), supported by the [p-But-calix[4]-(O)4] tetraanion. It was obtained from a stepwise reduction of [p-But-calix[4]-(O)4}2Nb2(Cl)2] (1) through the intermediate formation of a [Nb−Nb] dimer, [μ-p-But-calix[4]-(O)4}2Nb2] (2). Complex 3 reacted
导致从酮和醛合成铌亚烷基和铌亚烷基的活性化合物是 [NbIIINbIII] 二聚体,[p-But-calix[4]-(O)4}2Nb2Na2] (3),由 [ p-But-calix[4]-(O)4] 四阴离子。它是通过 [p-But-calix[4]-(O)4}2Nb2(Cl)2] (1) 通过中间形成 [Nb-Nb] 二聚体 [μ- p-But-calix[4]-(O)4}2Nb2] (2)。配合物 3 与酮和醛 RR'CO 反应,通过 NbNb 键与羰基官能团的复分解反应,形成等摩尔量的铌亚烷基 [p-But-calix[4]-(O)4}NbCRR' )]Na [R = R' = Ph, 4; R = Ph, R' = Me, 5; R = Cp2Fe,R' = Me,6;R=Ph,R'=CH2Ph,7;RR' = (CH2)4, 8; R = Prn, R' = H, 10;