A Highly Active System for the Metal-Free Aerobic Photocyanation of Tertiary Amines with Visible Light: Application to the Synthesis of Tetraponerines and Crispine A
作者:Julio Cesar Orejarena Pacheco、Alexander Lipp、Alexander M. Nauth、Fabian Acke、Jule-Philipp Dietz、Till Opatz
DOI:10.1002/chem.201504845
日期:2016.4.4
A highly efficient metal‐free catalytic system for the aerobic photocyanation of tertiary amines with visiblelight is reported. The use of air as terminal oxidant offers an improved safety profile compared with pure oxygen, the used compact fluorescent lamp (CFL) light sources are highly economical, and no halogenated solvents are required. This system not only proves to be effective for a wide variety
alpha-Aminonitriles inaccessible by traditional Strecker chemistry are obtained in redox-neutral fashion by direct amine alpha-cyanation/N-alkylation or alternatively, alpha-aminonitrile isomerization. These unprecedented transformations are catalyzed by simple carboxylic acids.
Al-MCM-41 catalyzed three-component Strecker-type synthesis of α-aminonitriles
Mesoporous aluminosilicate (Al-MCM-41) efficiently catalyzed the three-component Strecker-type reaction of benzylacetone and aniline with trimethylsilyl cyanide in CH2Cl2 at room temperature to afford the corresponding alpha-aminonitrile in excellent yields (up to 97%). Mesoporous silica (MCM-41), amorphous SiO2-Al2O3, and H-Y and H-ZSM-5 zeolites also catalyzed this reaction, but gave the desired product in lower yields. The Al-MCM-41 catalyzed three-component Strecker-type reaction was applicable to a wide range of ketones, aldehydes, and amines. Furthermore, the Al-MCM-41 catalyst could be applied to a fixed-bed flow reactor: The desired alpha-aminonitrile derivative was constantly produced in nearly 80% yields for 48 h. (C) 2010 Elsevier Ltd. All rights reserved.