A short synthesis of pyridines from deprotonated <i>α</i>-aminonitriles by an alkylation/RCM sequence
作者:Carina Weber、Marco M. Nebe、Lukas P.V. Kaluza、Till Opatz
DOI:10.1515/znb-2016-0005
日期:2016.6.1
Abstract α-Aminonitriles can serve as versatile key precursors for the synthesis of nitrogen containing heterocycles. After unsuccessful trials involving the [1,2]-Stevens rearrangement of nitrile-stabilized ammonium ylides, we herein report a simple three-step synthesis of substituted pyridines based on an alkylation/ring-closing metathesis/aromatization sequence.
A very simple one-step, environmentally friendly procedure for the synthesis of α-aminonitriles from aldehydes and ketones, using trimethylsilyl cyanide in the absence of solvent, is reported. The active catalyst of this three-component (Strecker) reaction was the amine employed in the transformation. In general, aldehydes react more rapidly than ketones and give almost quantitative yields of the corresponding α-aminonitriles in less than fifteen minutes. However, only cyclic ketones afford the corresponding α-aminonitriles in excellent chemical yields under these conditions.
Highly Enantioselective Titanium-Catalyzed Cyanation of Imines at Room Temperature
作者:Abdul Majeed Seayad、Balamurugan Ramalingam、Kazuhiko Yoshinaga、Takushi Nagata、Christina L. L. Chai
DOI:10.1021/ol902540h
日期:2010.1.15
A highly active and enantioselective titanium-catalyzed cyanation of imines at roomtemperature is described. The catalyst used is a partially hydrolyzed titanium alkoxide (PHTA) precatalyst together with a readily available N-salicyl-β-aminoalcohol ligand. Up to 98% ee was obtained with quantitative yields in 15 min of reaction time using 5 mol % of the catalyst. Various N-protecting groups such as
Trimethylsilyl cyanide addition to aldimines and its application in the synthesis of (S)-phenylglycine methyl ester
作者:B.A. Bhanu Prasad、Alakesh Bisai、Vinod K. Singh
DOI:10.1016/j.tetlet.2004.11.015
日期:2004.12
reaction) in the presence of LiClO4 or BF3·Et2O in acetonitrile has been studied. The reaction provided the addition products in very high yields. The method has been successfully utilized for the synthesis of (S)-phenylglycine methyl ester.
An iridium-catalyzed reductive nucleophilicaddition to secondary amides is reported. After the iridium-catalyzed reduction, the resulting imines can undergo the Strecker reaction, the Mannich reaction, allylation, and [3 + 2]-cycloaddition. The method shows high chemoselectivity in the presence of other functional groups such as methyl ester.