Rhodium(I)-catalyzed alternating co-oligomerization of carbon monoxide with olefins: Synthetic and mechanistic studies

Copolymerization of styrene with CO catalysed by palladium‐substituted 1,10‐phenanthroline bis(methoxycarbonyl) complexes [Pd(L—L)(COOMe) 2 ]

“…Actually, preformed palladium catalytic precursors, such as Pd(L1L) 2 (X) 2 (L1L = nitrogen or phosphorus bischelating ligands and X = PF 6 -, CF 3 COO -), allow one to reach good yields in ethylenecarbon monoxide copolymerization 4,5) . Many efforts have been also devoted to copolymerize CO with a-olefins, such as propene [6][7][8][9][10] and styrene [11][12][13][14][15][16][17][18][19][20][21] . Since in the latter case, the initation step is hypothesized to be a 2,1-insertion of styrene in a palladium carbomethoxy bond 22) , followed by CO insertion and successive 2,1-insertion of styrene in Pd-acyl bonds formed 23) , a new class of palladium bis(methoxycarbonyl) complexes, Pd(L1L)(COOMe) 2 , bearing substituted phenanthrolines as ligands, have been prepared 24) to prove their involvement in styrene-CO copolymerization.…”

Selective formation of pentan-3-one from carbon monoxide and ethene in methanol

“…2 Using triphenylphosphine complexes of rhodium, long chain polymers are not formed, but rather a mixture of oligoesters and oligoketones. 3 Hydrogen is again required, but this can be produced from added water via the water gas shift reaction; no reaction occurs in dry methanol in the absence of hydrogen. 3 We have previously shown that trialkylphosphine complexes of rhodium show high activity for the direct formation of alcohols 4,5 in hydrocarbonylation reactions of alkenes and that similar products are also formed in the absence of hydrogen, with the alcohol solvent acting as the source of hydrogen.…”

“…3 Hydrogen is again required, but this can be produced from added water via the water gas shift reaction; no reaction occurs in dry methanol in the absence of hydrogen. 3 We have previously shown that trialkylphosphine complexes of rhodium show high activity for the direct formation of alcohols 4,5 in hydrocarbonylation reactions of alkenes and that similar products are also formed in the absence of hydrogen, with the alcohol solvent acting as the source of hydrogen. 6 We now report that the same system can afford relatively high selectivity to pentan-3-one from CO and ethene in methanol.…”