C–H Bond Functionalization with the Formation of a C–C Bond: A Free Radical Condensation Reaction Based on the Phthalimido‐<i>N</i>‐oxyl Radical

Abstract

Abstract The development of a new chemical process that effects the conversion RH + C=C–C–X → R–C–C=C + HX, in which X is the phthalimido‐ N ‐oxyl radical (PINO · ), is reported. The reaction yields are high, mass balances are excellent, and C–H bond functionalization and C–C bond formation are achieved in a single transformation. The byproduct of the reaction, N ‐hydroxyphthalimide, precipitates from solution and can be easily removed by simple filtration (and recycled). The kinetic chain lengths are shorter and the reaction times are longer (relative to those of the analogous reactions of allyl bromides), most likely because PINO · is a less‐reactive hydrogen‐atom abstractor. There appears to be no significant difference in efficiency in the addition–elimination steps. Competition experiments reveal that Br · and PINO · are comparable in leaving group ability.