Metals in organic syntheses X. Olefin hydroformylation and hydrocarboalkoxylation competitively catalyzed by a [PtCl2(PPh3)2]-SnCl2 system

The system [PtCl2(PPh3)2]/SnCl2 significantly catalyzes only the hydroformylation of α-olefins at 100°C in EtOH, at P(CO)=P(H2)=65 atm; hydrocarboalkoxylation does not occur to an apreciable extent, even in the presence of potential activating agents (HCl, LiCl). The catalyst precursor has been recovered from the reaction medium, as the cationic complex [PtH(CO)(PPh3)2](SnCl3), having the SnCl3− anion non-directly bound to the platinum atom, and as trans-[PtCl(COR)(PPh3)2]. The latter complex is a (precursor) intermediate leading to an active catalytic species possessing at least one Pt-Sn bond which plays a key role in the catalysis