This work describes the carbonylation of hex-1-ene, cyclohexene, 2,3-dimethyl-but-1-ene and 2-methylpent-2-ene, their quaternary mixture and a real Venezuelan naphtha, catalyzed by a rhodium(I) [Rh(cod)(4-picoline) 2 ] (PF 6 ) (cod = 1,5-cyclooctadiene) complex immobilized on poly(4-vinylpiridine) (P(4-VP)) in contact with methanol under carbon monoxide atmosphere. The conversion (%) of olefins to carbonylated products for the individual olefins decreases in the order: hex-1-ene (63) [ cyclohexene (58) [ 2,3-dimethyl-but-1-ene (50) [ 2-methyl-pent-2-ene (31), under the following conditions: 0.5 g of P(4-VP) for [Rh] = 2 wt.% (1 9 10 -4 mol), 10 mL of CH 3 OH, [olefin] = 1 9 10 -2 mol, S/C = 100, P(CO) = 33 atm at 110°C for 24 h. Other products such as H 2 and CO 2 coming from the catalysis of the water-gas shift reaction are observed.

In this work the results of the study of the catalytic activity of the dinuclear gem-dithiolato-bridged rhodium complex [Rh 2 (l-S 2 CBn 2 )(cod) 2 ] (Bn = benzyl; cod = 1,5-cyclooctadiene) for the hydroformylation of hex-1-ene in CO/H 2 O, are presented. Under the best conditions for hydroformylation [P(CO) = 22 atm at 80°C, in 24 h, toluene/H 2 O = 8/2, v/v, hex-1-ene (3 mmol), [Rh] = 0.01 mmol, hex-1-ene/[Rh] = 15 molar ratio] the only organic products observed (detected by GC and GC-MS) were heptanal and 2-methylhexanal and traces of 2-hexene (isomerization product). In addition, the products of the water gas shift reaction, H 2 and CO 2 , were also obtained as competitive reaction of the hydroformylation process.

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This work focuses on the use of a gem-dithiolato-bridged rhodium(I) [Rh 2 (μ-S 2 CBn 2 )(cod) 2 ] complex (cod = 1,5-cyclooctadiene, Bn 2 CS 2 2 = 1,3-diphenyl-2,2-dithiolatopropane) dissolved in toluene in the presence of monodentate phosphite P-donor ligand (P(OPh) 3 ) under carbon monoxide/hydrogen (1:1, syngas) atmosphere as an effective catalyst for hydroformylation of some olefins (oxo-reactions). The capability of this system to catalyze the hydroformylation of hex-1-ene, cyclohexene, 2,3-dimethyl-but-1-ene and 2-methyl-pent-2-ene and their quaternary mixture (synthetic naphtha) has been demonstrated. This innovative method to perform the in situ hydroformylation of the olefins present in naphthas to oxygenated products would be a promissory work for a future industrial catalytic process applicable to gasoline improving based on oxo-reactions. An important observation is that variation of CO/H 2 pressure (6.8 34.0 atm), temperature (60 80 ºC), reaction time (2 10 h), rhodium concentration ((1.0 1.8)x10-3 mol/L) affect hydroformylation reaction rates. Optimal conversion to oxygenated products were achieved under [Rh] = 1.8 x10 -2 mol/L, P(CO/H 2 ) = 34 atm (CO/H 2 = 1:1) at 80 ºC for 10 h.

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