Photoinitiated ambient temperature copper-catalyzed atom transfer radical addition (ATRA) and cyclization (ATRC) reactions in the presence of free-radical diazo initiator (AIBN).

The use of UV light in copper-catalyzed atom transfer radical addition (ATRA) and cyclization (ATRC) reactions of various (poly)halogenated compounds to highly active alkenes in the presence of AIBN is reported. Radicals generated from photodecomposition of AIBN efficiently regenerated the copper(I) complex at ambient temperature enabling ATRA of CCl(4) and CBr(4) with catalyst loadings as low as 0.05 mol-%.

Kinetic studies of the initiation step in copper catalyzed atom transfer radical addition (ATRA) in the presence of free radical diazo initiators as reducing agents.

Kinetic parameters for the reduction of copper(II) complexes in atom transfer radical addition (ATRA) in the presence of free-radical diazo initiator (AIBN) were determined using both experimental and kinetic modeling techniques. The rate constant of decomposition of AIBN (k(dc)) in various solvents was determined at 60 degrees C using UV-vis spectroscopy. Rate constants of deactivation (k(d,AIBN)) of [Cu(II)(TPMA)Cl][Cl] (TPMA = tris(2-pyridylmethyl)amine), [Cu(II)(Me(6)TREN)Cl][Cl] (Me(6)TREN = tris[2-(N,N-dimethylamino)ethyl]amine), [Cu(II)(PMDETA)Cl(2)] (PMDETA = N,N,N',N'',N''-pentamethyldiethylenetriamine), and [Cu(II)(bpy)(2)Cl][Cl] (bpy = 2,2'-bipyridine) complexes by radicals generated from the decomposition of AIBN were measured using the TEMPO-trapping method in a competitive clock reaction.

Persistent radical effect in action: kinetic studies of copper-catalyzed atom transfer radical addition in the presence of free-radical diazo initiators as reducing agents.

Kinetic features of the atom transfer radical addition (ATRA) of CCl(4) to 1-octene, styrene, and methyl acrylate catalyzed by [Cu(II)(TPMA)Cl][Cl] (TPMA = tris(2-pyridylmethyl)amine) in the presence of free-radical diazo initiator (AIBN) as a reducing agent were investigated. For 1-octene, the catalyst concentration was found to affect the alkene conversion and the yield of monoadduct for [1-octene](0)/[Cu(II)](0) ratios above 10,000:1. A more pronounced effect of the catalyst loading was observed in the case of methyl acrylate and styrene, due to the formation of AIBN-initiated oligomeric/polymeric side products.