Insertion of CO 2 into the Ru-C bonds of cis - and trans -Ru(dmpe) 2 Me 2 (dmpe = Me 2 PCH 2 CH 2 PMe 2 )

The reaction of cis-Ru(dmpe)2Me2 (1) and trans-Ru(dmpe)2Me2 (2) [dmpe = 1, 2-bis(dimethylphosphino)ethane] with carbon dioxide was investigated. Addition of 3−4 atm of CO2 at 300 K to trans-Ru(dmpe)2Me2 (2) results in the formation of the expected methyl acetate complex trans-Ru(dmpe)2(OCOMe)Me (3) and bis-acetate complex trans-Ru(dmpe)2(OCOMe)2 (5). Addition of 3−4 atm of CO2 at 300 K to cis-Ru(dmpe)2Me2 (1) leads to the formation of the expected methyl acetate complex cis-Ru(dmpe)2(OCOMe)Me (4) and to the bis-acetate complex cis-Ru(dmpe)2(OCOMe)2 (6) when the reaction mixture is heated at 333 K. A carbonate byproduct, Ru(dmpe)2CO3 (7), is also formed in both reactions. As part of this study, a new ruthenium methyl hydride complex has been synthesized, Ru(dmpe)2CH3H (8), and its isomerization properties and reactions with CO2 are reported. At 300 K, addition of CO2 to 8 forms the methyl formate product Ru(dmpe)2(O2CH)CH3 (9). The reaction with CO2 is reversible, and on heating, the methyl formate 9 decar...