Electronic structure and electrophilic reactivity of discrete copper diphenylcarbenes

Synthesis and structures of isopropyl-β-diketiminato copper(I) complexes

“…27 Monomer-dimer equilibria similar to equilibrium [3] in Scheme 2 have been observed for nacnac Bn Cu, which forms a diphenylacetylenebridged dimer in the solid state and a monomeric complex in solution when excess diphenylacetylene is present, 12 and for nacnac Ar Cu complexes, which display an equilibrium between a monomeric and a dimeric benzene-coordinated complex in solution. 7,25 While single-crystal diffraction studies confirmed the formation of 4, we were unable to obtain satisfactory elemental analyses, even from the crystalline material. Synthesis of 4 was reported at the time of submission of this article by Arii 13 Although not discussed therein, they also observed a variable ratio of two products in NMR spectra of 4.…”

“…5 Warren and co-workers isolated a nacnac copper carbene complex, which they employed in catalytic cyclopropanation, and used copper diketiminates for amination reactions. [6][7][8] While most applications of diketiminate ligands revolve around N-aryl substituents, their Nalkyl derivatives have not been well-exploited. For copper(I), they are limited to applications in atomic layer deposition 9 or analyses of copper-ligand bonding.…”

Stereoselectivity induced by support confinement effects. Aza-pyridinoxazolines: A new family of C1-symmetric ligands for copper-catalyzed enantioselective cyclopropanation reactions

“…An extensive study on the importance of the nature of the support has been recently reported, confirming the need of having a lamellar anionic support to observe such surface 55 confinement effects. 10 A simple model has been proposed to explain those results, taking into account the known cyclopropanation reaction mechanism [11][12][13][14][15][16][17][18][19][20] and the strong ionpair interaction between the key copper-carbene intermediate and the support surface, as well as the steric constraints of the 60 catalytic complex. From that model we proposed the synthesis of chiral ligands without C 2 symmetry as a method to enhance the surface-complex proximity and hence the support-complex interaction, allowing the surface to effectively shield one face of the complex.…”

Binuclear β-diketiminate complexes of copper(i)

“…[3][4][5][6][7][8][9][10][11][12][13][14][15] Warren and coworkers have expanded the oxidation chemistry of copper(I) β-diketiminate complexes to include diazoalkanes, PhI=NTs, organoazides and tert-butylperoxide. [16][17][18][19][20][21][22][23][24][25][26][27][28] These stoichiometric studies are part of a broader programme, developing exciting synthetic protocols for the functionalization of carbon-hydrogen bonds in hydrocarbons. The catalytic generation of a monomeric copper nitrene intermediate and its transformation to a copper(II) amide by hydrogen atom abstraction has been proposed as a key step in the transformation of carbon-hydrogen bonds to carbon-nitrogen bonds.…”