A novel Pd(II)-catalyzed oxidative approach to construct polysubstituted pyrroles from N-homoallylicamines and arylboronic acids was developed. This transformation is supposed to proceed through cascade formation of C-C and C-N bonds via oxidative arylation of unactive alkenes, followed by intramolecular aza-Wacker cyclization.
Dehydrogenation and α-functionalization of secondary amines by visible-light-mediated catalysis
A visible-light-mediated process for dehydrogenation of amines has been described. The given protocol showed a broad substrate scope, mild reaction conditions and excellent results without the requirement of tedious purification. This process can be applied in one-pot functionalization of secondary amines with various nucleophiles through the cooperation of visible-light and Lewis acid catalysis, leading
Economical and efficient aqueous reductions of high melting-point imines and nitroarenes to amines: promotion effects of granular PTFE
作者:Tao Li、Xiaoxue Cui、Lili Sun、Chunbao Li
DOI:10.1039/c4ra04528a
日期:——
The reductions of high melting-point imines and nitroarenes to amines in aqueous media using Zn powder, granular PTFE (polytetrafluoroethylene), catalytic Aliquat 336 and NH4Cl or 5% NaOH at room temperature have been achieved. A major advantage of this procedure is that the cost of the catalyst is only 1/7200 of that of a previously reported nitroaromatic aqueous reduction catalyst. Altogether 13 imines and 11 nitroarenes were reduced to the corresponding amines with excellent yields. The effects of the amount of granular PTFE, and solubilities and melting points of the substrates, and melting points of the products on the reaction rates are discussed. For the first time, the relationship between the aqueous reaction rates and melting points of the products was investigated, which leads to a conclusion that lower melting-point products form faster than higher melting-point ones in the aqueous reductions. The Aliquat 336, granular PTFE and water are all recyclable.