Carboxylatocopper(I) complexes

Crystal and molecular structure of a new type of tetranuclear mixed valence copper complex: Cu4Ac6(Ph3P)4(Ac = O2CMe)

“…The co-ordination polyhedron of Cul in Cu4Ac6( Ph3P)4 shows significant differences in CuLO distances in comparison with those found for C U A C ( P ~, P ) ~. ~The CuLO(1) distance is shorter (2.125 A) and the CuLO(2) distance is longer (2.385 A) than the analogous distances in CuAc(Ph3P)*6 (2.162 and 2.257 A, respectively). The remaining distances including the bond lengths in the Ph3P ligand are not significantly different from those in the C U A C ( P ~~P ) ~ complex.6 The complex C U ~A C ~( P ~~P ) ~ represents a new structural type among mixed valence CuILCuI carboxylates.…”

Preparation, Infrared Spectra, Electronic Spectra, and Magnetic Moments of Copper(II) Complexes of N-Acetylglycine and Their Amine Adducts

“…This was not foreseen since biden--tate coordination through the carboxyl oxygens may be suggested (25) by the pKA value of Nacetylglycine (pKA = 3.60 (26), 3.632 (27), or 3.9 (in 2 0 x dioxane) (28)) and bidentate coordination through the nitrogen and terminal carboxyl oxygen would have led to a five-membered chelate ring as has been found in similar situations (29,30). The experimental results could suggest that the carboxylates, in the adducts of the aliphatic heterocyclic amines, do not give an asymmetrically bidentate coordination, as previously found for the copper(l1) acetate and propionate adducts (lo), therefore the mono or bidentate carboxylate coordination depends only on the nature of the carboxylic acids.…”

Copper‐Catalyzed Borylation Reactions of Alkynes and Arynes

“…We first carried out the reaction of 4‐octyne ( 1 a ) with bis(pinacolato)diboron ((pin)BB(pin)) in the presence of PCy 3 and Cu(OAc) 2 ,7, 8 and observed that the BB bond was smoothly added to the CC bond in a cis fashion to afford diborylated product 2 a in 82 % yield (Table 1, entry 1). Trialkylphosphine ligands P( t Bu) 3 and P( n Oc) 3 also promoted the diborylation, but a prolonged reaction time was required in the latter case (Table 1, entries 2 and 3, respectively); the reaction with PPh 3 resulted in a moderate yield (entry 4).…”