Thermal aromatic Claisen rearrangement and Strecker reaction of alkyl(allyl)-aryl ethers under green reaction conditions: Efficient and clean preparation of ortho-allyl phenols (naphthols) and alkyl(allyl)oxyarene-based γ-amino nitriles

Kheila N. Silgado-Gómez, Vladimir V. Kouznetsov
2017 Mediterranean Journal of Chemistry  
<p class="Mabstract">Chemical transformations of 13 diverse allyl(alkyl)-aryl ethers, easily prepared using Williamson reaction of different hydroxyarenes and allyl bromide and alkyl (n-butyl, n-octyl) bromides, were studied. Thermal aromatic Claisen rearrangement of allyl-aryl ethers to obtain ortho-allyl phenols (naphthols) employing propylene carbonate as a nontoxic and biodegradable solvent was described for the first time. The use of this green solvent allowed to enhance notably product
more » ... lds and reduce significantly the reaction time comparing with the use of 1,2-dichlorobenzene, toxic solvent, which is traditionally employed in this type of Claisen rearrangement. Three-component Strecker reaction of selected alkyl(allyl)-aryl ethers with formyl function on aryl fragment and, piperidine and potassium cyanide in the presence of sulfuric acid supported on silica gel (SSA, SiO<sub>2-</sub>O-SO<sub>3</sub>H) under mild reaction conditions was used in the preparation of new γ-amino nitriles, analogues of alkaloid girgensohnine [2-(4-hydroxyphenyl)-2-(piperidin-1-yl)acetonitrile], a perspective biological model in the search for new insecticidal agrochemicals against Aedes aegypti. The use of SSA, an inexpensive and reusable solid catalyst, allowed to obtain new series of 2-[4-alkyl(allyl)oxyphenyl]-2-(piperidin-1-yl)acetonitriles in short time at room temperature with good yields.</p>
doi:10.13171/mjc65/01711201245-kouznetsov fatcat:ojpl6ce3frgnrjnumwpfbj2vuq