Recent Advances in the Nitration of Olefins

Abstract

Nitroolefins are important synthetic intermediates in the field of organic synthesis as well as in medicinal chemistry. The high reactivity of nitroalkenes due to the polarized double bond which enables them to act as Michael acceptor in conjugate addition reactions, or as a dienophile in cycloaddition makes it an essential synthetic handle for accessing complex molecules. The classical method to prepare nitroolefins is indeed the Henry nitroaldol reaction, where a carbonyl compound and nitroalkane are condensed in presence of base. Direct nitration of olefin, on the other hand, serves as a useful alternative as olefins are abundant, have broad commercial availability and easy to manipulate. In this context, numerous methods have been developed over the last few decades, focusing on direct nitration of styrene and aliphatic olefins. Furthermore, thorough literature search revealed that implementation of this class of reactions are gaining momentum as a preferred pathway to access nitroolefins, despite the presence of a powerful technique such as Henry reaction. In this review, we aim to cover recent advances in direct olefin nitration and their importance in accessing biorelevant molecules, total synthesis targets and future outlook in this specific research area.

Radical spirocyclization of biaryl ynones for the construction of NO2-containing spiro[5.5]trienones

“…Nitro-containing compounds are of great significance due to their easy and divergent transformability as key precursors in high-energy materials, dyes, pharmaceuticals and pesticides. 1 In the past two decades, radical involved nitration has received great attention in organic chemical synthesis. 2 However, methods for the synthesis of nitro compounds based on the addition of nitro radicals to alkynes are difficult since the nitrovinyl intermediate is highly unstable and has high reactivity and a short lifetime.…”