16293-12-2Relevant articles and documents
Increasing the Activity of Copper Guanidine Quinoline Catalysts: Substitution at the Quinoline Backbone Leads to Highly Active Complexes for ATRP
Kr?ckert, Konstantin W.,Mannsperger, Johannes S.,R?sener, Thomas,Hoffmann, Alexander,Herres-Pawlis, Sonja
, p. 832 - 842 (2021)
Copper bromide complexes with the ligands TMG6NO2qu, TMG6Brqu, TMG6Methoxyqu, TMG6NMe2qu, TMG6EHOqu and TMG6dBAqu were examined regarding their activity in atom transfer radical polymerization (ATRP). The ligands were inspired by 1,1,3,3-tetramethyl-2-(quinolin-8-yl)guanidine (TMGqu) and the substituents have been chosen with a large range between electron withdrawing and donating abilities. The donor properties of the ligands can be strongly influenced and further highly active catalysts based on these systems can be obtained. The ligands with strong donating moieties were in addition modified by alkyl groups to increase the solubility in apolar monomers like styrene. CuI and CuII bromide complexes were crystallised and the structural data correlated to the different substituents and the catalyst activity. The electrochemical potentials E1/2, the equilibrium constants KATRP and rate constants kact and kdeact were determined. Polymerizations of styrene were conducted in solution whereas the catalyst based on TMG6EHOqu shows a good solubility and performance in bulk.
A convenient copper-catalyzed direct animation of nitroarenes with 9-alkylhydroxylamines
Seko, Shinzo,Miyake, Kunihito,Kavvamura, Norio
, p. 1437 - 1444 (2007/10/03)
O-Alkylhydroxylamines, particularly O-methylhydroxylamine, aminate nitroarenes in the presence of a strong base and a copper catalyst to give aminonitroarenes in good yields, ortho- or para-Animation with respect to the nitro group takes place, and in some cases the ortho-aminated product is preferentially obtained. With 3-substituted nitrobenzenes where the substituent has a lone pair of electrons, preferential amination occurs at the 2-position to give the sterically most congested 3c-f, 14 and 22g.