Reactivity of triplet-state nitrophenylcarbenes towards cis-butene
Abstract
A series of nitrophenylcarbenes ArCH (Ar = 3-Me-4-O2NC6H3, 3,5-Me2-4-O2NC6H2, 2-Me-4-O2NC6H3, and 2-Me-5-O2NC6H3), generated photolytically, was found to insert as well as add (non-stereospecifically) to a high degree to cis-butene. Results indicate that both m- or p-nitro-substituents enhance triplet populations. Further methyl substitution, however, can enhance or reduce triplet populations if substituted ortho to the carbene centre or nitro-group, respectively.