153447-37-1Relevant articles and documents
Intramolecular and intermolecular hydrogen bonding in triphenylphosphine derivatives of copper(I) carboxylates, (Ph3P)2CuO2C(CH2)nCOOH. Role of copper(I) in the decarboxylation of malonic acid and its derivatives
Darensbourg, Donald J.,Holtcamp, Matthew W.,Khandelwal, Bandana,Reibenspies, Joseph H.
, p. 531 - 537 (2008/10/08)
The air-sensitive copper(I) hydrogen dicarboxylate complexes (Ph3P)2CuO2C(CH2)nCOOH (n =1,2) and derivatives thereof have been synthesized from 1 equiv of the corresponding dicarboxylic acid and cuprous butyrate. The solid-state structures of these derivatives exhibit quite different hydrogen bonding motifs. That is, the malonate derivative (1) contains a three-coordinate copper(I) center composed of two phosphine ligands and a monodentate carboxylate ligand. The appended carboxylic acid forms a strong intramolecular hydrogen bond with the distal oxygen atom of the carboxylate group bound to copper. On the other hand, the succinate derivative (2) displays a polymeric chain structure in which the carboxylic acid moiety is intermolecularly hydrogen bonded to the neighboring complex. Complex 1 undergoes decarboxylation in tetrahydrofuran solution, whereas complex 2 is stable toward decarboxylation. The phenylmalonic acid analog of complex 1 similarly undergoes carbon dioxide extrusion under milder conditions than 1 and has been shown to proceed via a first-order process. This copper(I) derivative is a very effective catalyst for the decarboxylation of phenylmalonic acid to phenylacetic acid and carbon dioxide. This process has been shown to be first-order in copper(I) complex and zero order in [acid]. The rate constants for CO2 extrusion from the complex and for acid decarboxylation are very similar, an observation consistent with a reaction pathway for the catalytic decarboxylation where the slow step is the extrusion of CO2 from the half-acid copper(I) complex. The role of intra- and intermolecular hydrogen bonding involving complex 1 on the CO2 extrusion process is discussed. Crystal data for 1: space group P1, a = 12.949(6)?, b = 13.162(7) ?, c= 13.253(6) ?, α = 60.73(3)°, β = 85.26(4)°, γ = 68.62(4)°, Z = 2, R = 5.80%. Crystal data for 2: space group P21/n, a = 13.141(2) ?, b = 13.0070(10) ?, c = 20.814(3) ?, β = 100.300(10)°, Z = 4, R = 4.00%.
