부산대학교 도서관

The activation of abundant molecules such as hydrocarbons and atmospheric nitrogen (N.sub.2) remains a challenge because these molecules are often inert. The formation of carbon-nitrogen bonds from N.sub.2 typically has required reactive organic precursors that are incompatible with the reducing conditions that promote N.sub.2 reactivity.sup.1, which has prevented catalysis. Here we report a diketiminate-supported iron system that sequentially activates benzene and N.sub.2 to form aniline derivatives. The key to this coupling reaction is the partial silylation of a reduced iron-dinitrogen complex, followed by migration of a benzene-derived aryl group to the nitrogen. Further reduction releases N.sub.2-derived aniline, and the resulting iron species can re-enter the cyclic pathway. Specifically, we show that an easily prepared diketiminate iron bromide complex.sup.2 mediates the one-pot conversion of several petroleum-derived arenes into the corresponding silylated aniline derivatives, by using a mixture of sodium powder, crown ether, trimethylsilyl bromide and N.sub.2 as the nitrogen source. Numerous compounds along the cyclic pathway are isolated and crystallographically characterized, and their reactivity supports a mechanism for sequential hydrocarbon activation and N.sub.2 functionalization. This strategy couples nitrogen atoms from N.sub.2 with abundant hydrocarbons, and maps a route towards future catalytic systems. An iron complex sequentially activates N.sub.2 and C-H bonds in benzene to form aniline, with coupling achieved through partial silylation of a reduced iron-nitrogen complex and phenyl migration.
Author(s): Sean F. McWilliams [sup.1] , Daniël L. J. Broere [sup.1] [sup.3] , Connor J. V. Halliday [sup.2] , Samuel M. Bhutto [sup.1] , Brandon Q. Mercado [sup.1] , Patrick [...]