17787-26-7Relevant articles and documents
The influence of steric bulk on the geometry of triarylphosphite-based palladacycles and their tricyclohexylphosphine adducts
Bedford, Robin B.,Betham, Michael,Coles, Simon J.,Horton, Peter N.,López-Sáez, María-José
, p. 1003 - 1010 (2008/10/09)
A range of complexes of the formula [PdCl2{P(OAr) 3}2] have been synthesized in order to determine the effect of steric bulk on stereochemistry, one example [PdCl 2{P(OC6H4-2-tBu)3} 2] has been structurally characterized. Three palladacyclic complexes [{Pd(μ-Cl)(κ2-P,C-P(OC6H3R)(OC 6H4R)2)}2] have been synthesized (R = H, 2-iPr, 2-tBu) and two have been characterized by crystallography (R = H and tBu). The latter adopts the expected trans geometry while the former is cis. In this case, the driving force for the cis geometry seems to be intermolecular interactions in the crystal structure which are disrupted on substitution. We also report an unusual solvolysis reaction.
Structural studies of PdCl2L2 complexes with fluorinated phosphines, phosphites, and phosphinites as precursors of benzyl bromide carbonylation catalysts, and and X-ray crystal structure of cis-PdCl2[PPh2 (OEt)]2
Trzeciak,Bartosz-Bechowski,Ciunik,Niesyty,Ziolkowski
, p. 752 - 759 (2007/10/03)
PdCl2L2-type complexes with phosphines (L = PPhx(C6F5)3-x (x = 0-3)), phosphites (L = P(OMe)3, P(OPh)3, P(OEt)3), and phosphinites (L = PPh2 (OC6F5), PPh2(O-3,5-F2 C6H3), PPh2(OEt), PPh2 (O-n-Bu), PPh2(O-t-Bu)) were synthesized and characterized by UV-vis and 31P NMR methods. PdCl2L2 complexes with less sterically demanding phosphines (Θ 2[PPh2(OEt)]2. These complexes react with CO in the presence of NEt3 forming Pd(CO)xLy (x + y = 4) type carbonyls characterized by IR spectra. All PdCl2L2 complexes studied are active as precursors of benzyl bromide carbonylation catalysts at 40°C and 1 atm CO; however, the activity of the cis isomers is higher than that of the trans isomers. The highest yields of the carbonylation product, phenylacetic acid methyl ester, were obtained using cis-PdCl2[P(OMe)3]2 (92%), cis-PdCl2[P(OPh)3]2 (89%), and cis-PdCl2[PPh2(O-n-Bu)]2 (78%) as catalyst precursors.