Stereoselective Synthesis of Multisubstituted Cyclohexanes by Reaction of Conjugated Enynones with Malononitrile in the Presence of LDA
Anastasiya V. Igushkina,
Alexander A. Golovanov,
Irina A. Boyarskaya,
Ilya E. Kolesnikov,
Aleksander V. Vasilyev
Affiliations
Anastasiya V. Igushkina
Department of Organic Chemistry, Institute of Chemistry, Saint Petersburg State University, Universitetskaya nab., 7/9, 199034 Saint Petersburg, Russia
Alexander A. Golovanov
Department of Chemistry, Chemical Processes and Technologies, Togliatti State University, Belorusskaya ul., 14, 445667 Togliatti, Russia
Irina A. Boyarskaya
Department of Organic Chemistry, Institute of Chemistry, Saint Petersburg State University, Universitetskaya nab., 7/9, 199034 Saint Petersburg, Russia
Ilya E. Kolesnikov
Center for Optical and Laser Materials Research, St. Petersburg State University, Ulyanovskaya ul., 5, 198504 Saint Petersburg, Russia
Aleksander V. Vasilyev
Department of Organic Chemistry, Institute of Chemistry, Saint Petersburg State University, Universitetskaya nab., 7/9, 199034 Saint Petersburg, Russia
Reaction of linear conjugated enynones, 1,5-diarylpent-2-en-4-yn-1-ones, with malononitrile in the presence of lithium diisopropylamide LDA, as a base, in THF at room temperature for 3–7 h resulted in the formation of the product of dimerization, multisubstituted polyfunctional cyclohexanes, 4-aryl-2,6-bis(arylethynyl)-3-(aryloxomethyl)-4-hydroxycyclohexane-1,1-dicarbonitriles, in yields up to 60%. Varying the reaction conditions by decreasing time and temperature and changing the ratio of starting compounds (enynone and malononitrile) allowed isolating some intermediate compounds, which confirmed a plausible reaction mechanism. The relative stability of possible stereoisomers of such cyclohexanes was estimated by quantum chemical calculations (DFT method). The obtained cyclohexanes were found to possess photoluminescent properties.
