Mesoporous Ethane−Silicas Functionalized with a Bulky N-Heterocyclic Carbene for Suzuki−Miyaura Coupling of Aryl Chlorides and Benzyl Chlorides

摘要: By co-condensation of IMes [IMes = N,N′-bis(2,6-dimethylphenyl)imidazol-2-ylidene]-bridged organosilane and bis(triethoxysilyl)ethane in the presence template, a new mesoporous ethane−silica with built-in bulky N-heterocyclic carbene (NHC) precursor framework was synthesized. N2 sorption, XRD, TEM characterizations revealed that synthesized material had an ordered mesostructure. FT-IR solid state NMR investigations confirmed moiety covalently integrated materials. Such functionalized able to coordinate Pd(OAc)2, leading active catalyst for Suzuki−Miyaura couplings challenging aryl chlorides benzyl under relatively mild conditions. using isopropyl alcohol as solvent KOtBu base, 78% yield biphenyl achieved 0.5 mol % Pd at 80 °C within 24 h. This could be reused eight times without significant decrease activity. The high recyclability may attri...