Herein, the synthesis of (Z)-α,β-unsaturated nitriles by a sequential hydroformylation/Knoevenagel reaction has been first developed. A variety of crude α-olefins from Fischer–Tropsch synthesis, internal and special olefins, as well as alkynes could be transformed into value-added alkenyl nitriles (39 examples) up to 90% yield. Remarkably, compared with commonly used tedious multistep reactions, the
在此,首次开发了通过顺序加氢甲酰化/Knoevenagel 反应合成 ( Z )-α,β-不饱和腈。来自费-托合成的各种粗α-烯烃、内烯烃和特殊烯烃以及炔烃可以转化为增值的烯基腈(39 个例子),产率高达 90%。值得注意的是,与常用的繁琐的多步反应相比,一锅法的特点是原料便宜且容易获得,具有优异的化学选择性、区域选择性和立体选择性,反应条件非常温和,易于放大生产。
Direct Synthesis of α,β-Unsaturated Nitriles Catalyzed by Nonionic Superbases
作者:Bosco A. D'Sa、Philip Kisanga、John G. Verkade
DOI:10.1021/jo972343u
日期:1998.6.1
We report herein the use of 3-30 mol % of a new class of tricyclic strong nonionic Lewis bases P(MeNCH2CH2)(3)N and P(HNCH2CH2)(i-PrNCH2CH2)(2)N for the direct catalytic synthesis of a variety of functionalized alpha,beta-unsaturated nitriles in high yields from aldehydes and acetonitrile or benzyl cyanide at 40-50 degrees C. Evidence for a novel mechanistic pathway proposed for this reaction in a polar protic solvent such as methanol, and a nonpolar aprotic solvent such as benzene is also presented. Under these conditions, primary and secondary aliphatic aldehydes do not condense satisfactorily with acetonitrile to give the alpha,beta-unsaturated nitrile, and ketones do not condense with either benzyl cyanide or acetonitrile.