Unexpected Heterocyclization of Electrophilic Alkenes by Tetranitromethane in the Presence of Triethylamine. Synthesis of 3-Nitroisoxazoles
journal contributionposted on 07.05.2010, 00:00 by Yulia A. Volkova, Elena B. Averina, Yuri K. Grishin, Per Bruheim, Tamara S. Kuznetsova, Nikolai S. Zefirov
Novel reaction of tetranitromethane (TNM) with electrophilic alkenes in the presence of triethylamine yielding substituted 3-nitroisoxazoles was found and studied. Triethylamine increases the reactivity of TNM toward electrophilic alkenes promoting their heterocyclization, and the reactions proceed in an unusual way. A variety of α,β-unsaturated aldehydes, ketones, esters, amides, phosphonates, and nitro and sulfur compounds was involved in the heterocyclization reaction, and a wide range of functionalized 3-nitroisoxazoles was obtained in good to high yields. The scope and limitations of the reaction and the mechanistic aspects are discussed.