Synthesis tricyanovinyl derivatives via one-pot tandem reactions with heterogeneous catalyst Au@Cu(II)-MOF

Abstract

In this article, the heterogeneous catalyst of Au@Cu(II)-MOF was prepared with high performance catalytic activities. By adding 5% mol Au@Cu(II)-MOF, the substrate of 2,6-di-tert-butylphenol (1) was oxidized to 2,6-di-tert-butyl-p-benzoquinone (2) with the yield of 99% using H2O2 as an oxidizing reagent. Moreover, treating the catalytic reaction mixture with malononitrile, one new product of 2-(3,5-di-tert-butyl-4-hydroxyphenyl)ethane-1,1,2,-tricarbonitrile (3) was obtained with the isolated yield of 87%. However, in the absence of the catalyst of Au@Cu(II)-MOF, the intermedia of 2 and malononitrile react to form a product not 3 but its isomer 2-(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dien-1-ylidene)ethane-1,1,2,-tricarbonitrile (4). At the meanwhile, in the presence of Au@Cu(II)-MOF and H2O2, the product of 3 with comparable isolated yield of 86% was isolated when 1 and malononitrile directly reacted during one pot tandem reaction. Furthermore, the tautomerization of 3 and 4 was also observed in CH2Cl2 solution driven by trimethylamine and acetic acid.