Phenylacetylene carbonylation catalysed by Pd(II) and Rh(III) intercalated in zirconium phosphates

Palladium(II) and rhodium(III) ions, or palladium(II) complexes (Pd-L) with bidentate N-donor ligands such as 2,2'-bipyridyl (bipy) and 1,10-phenanthroline (phen), intercalated in the layers of zirconium hydrogen phosphate, in ct or gamma phases (alpha- or gamma-ZrP), catalyze both single and double methoxo-carbonylation of phenylacetylene, The monocarbonylation products, PhC(COOCH3)=CH2 (1) and its regio isomer PhCH=CH(COOCH3) (2) are obtained when phenylacetylene reacts, in methanol, under CO pressure (1-4MPa), at temperatures of 80-130 degrees C, When the reaction is carried out under oxidative conditions using a CO/O-2 mixture, double-carbonylation products are obtained as well as monofunctionalized phenylacetylene. The double-carbonylation product PhC (COOCH3)=CH(COOCH3) (3) and the corresponding anhydride PhCCO(O)=CHCO (4) are obtained when tbe process Is earned out with a CO/O-2 mixture under pressure (2-4 MPa; pO(2) = 0.8 MPa) at 60-100 degrees C, using methanol or acetonitrile as solvent. When the reaction is carried out in the presence of tertiary amines such as NEt3 or NPh3, under mild pressure conditions (0.4-0.7 MPa) at 60-90 degrees C, the triple bond remains unchanged and the monocarboxylate PhC=CCOOCH3 (5) is isolated. Compound 5 is also prepared in a neutral medium when gamma-Zr-Rh3+ is used as catalyst. Copyright (C) 2000 John Wiley & Sons, Ltd.