Denitrative radical-induced coupling reactions of nitroalkenes

The classical reactivity of nitroalkenes, involving regioselective 1,4-addition by nucleophilic reagents, can be modified in β-nitrostyrenes using free radical species, which selectively add to nitro-bearing unsaturated carbon. The resulting stabilized benzylic radical undergoes a denitrative process leading to the formation of substituted alkenes. Alkyl and aryl radicals can be employed in this process, which can also be extended to the use of sulfur- and phosphorus-centered radicals. These radical species can be generated using oxidative, reductive or photocatalyzed procedures, which also ensure notable diastereoselectivity in alkene formation. Although currently applied only to β-nitrostyrenes, this approach could potentially be extended to any nitroalkene bearing a radical-stabilizing group at the beta position.