[60802-43-9] · C42H42Cl2P2Pd · Dichlorobis(tri-p-tolylphosphine)palladium(II) · (MW 786.06)
(catalyst for linear carbonylation of a-alkenes with alcohols2-4)
Alternate Name: trans-dichlorobis(tri-p-tolylphosphine)palladium(II).
Preparative Method: by treating an aqueous solution of commercially available K2PdCl2 with tri-p-tolylphosphine in dichloromethane using Bu4NCl as a phase-transfer catalyst.1
The title reagent has been used in bimetallic complexes with Group 14 metal halides for linear carbonylation of a-alkenes with alcohols.2-4 Several alkyl and aryl esters of alkanoic acids have been prepared by reaction of a-alkenes with carbon monoxide and nucleophilic co-reactants using Et4N+SnCl3- and [(p-Tol)3P]2PdCl2 as a catalyst system. In a typical procedure, a mixture of 1-octene (400 mmol), ethanol (400 mmol), Et4N+SnCl3- (40 mmol), and [(p-Tol)3P]2PdCl2 (4 mmol) was heated for 3-6 h at 80-95 °C under nitrogen while introducing CO at 1500 psi to give 84% ethyl nonanoate with 91% conversion and 83% selectivity (eq 1).2
The title reagent has been used as a catalyst in aromatic acetonylation to obtain arylacetones from acetonyltri-n-butyltin (prepared from Tri-n-butyl(methoxy)stannane and Isopropenyl Acetate in situ, eq 2) and aryl halides.5 In a typical procedure, a solution of methoxytributylstannane (15 mmol), isopropenyl acetate (15 mmol), aryl bromide (10 mmol), and the palladium complex (0.1 mmol) in toluene (5 mL) was heated for 5 h (eq 3).
(Ph3As)2PtCl2-SnCl2 has been used for linear carbonylation of a-alkenes with alcohols and has shown good regioselectivity.6 (Ph3P)2PdCl2-SnCl2 has also been reported to give similar results.4 Dichlorobis(tri-o-tolylphosphine)palladium(II) is a preferred catalyst in aromatic acetonylation to prepare arylacetones.5
Janak K. Padia
Parke-Davis Pharmaceutical Research, Ann Arbor, MI, USA