Photochemical Synthesis of Bis(η²‐methyl acrylate)tricarbonylruthenium

Complexes of Ruthenium and Osmium Containing η2–η6 Hydrocarbon Ligands: (i) Complexes not Containing Cyclobutadiene, Cyclopentadienyl or η-Arene Coligands

“…These are useful precursors for asymmetric catalytic hydrogenation, the diene being easily displaced from both complexes by atropoisomeric ditertiary phosphines (P-P) to give [Ru(O 2 CR) 2 (P-P)] (R = Me, CF 3 ). 100 Aqua Ultraviolet irradiation o f [Os 3 (CO) 12 ] with butadiene at 353 K gives [Os(CO) 3 (r|-C 4 H 6 )] as a lowmelting, colourless solid; the 1,3-pentadiene complex is obtained similarly. 107 The coupling constants !^c -c between the inner and outer diene carbon atoms and the geminal proton coupling constants for these complexes imply significant rehybridization towards sp' at the terminal carbon atoms, this tendency increasing in the order Fe < Ru < Os.…”

“…108 12 ] to give exo-and erafo-Ru(CO) 3 complexes (36) and (37); surprisingly, the pentaene does not displace cod f r o m [Ru(CO) 3 (t|-cod)]. Dinuclear complexes of the pentaene containing both Fe(CO) 3 and Ru(CO) 3 groups have also been prepared.…”

“…12 ] in the presence of 2,3-dimethylbutadiene as hydrogen acceptor to give the ruthenacyclopentadiene (42). 112 Intramolecular hydrogen transfer occurs in the reactions of linear tetraenes with [Ru 3 (CO) 12 ] (Equation (6)).…”

“…In contrast to the iron system, there is no evidence for coupling o f the alkene ligands, although on treatment o f (4) with dimethyl cyclobut-3-ene-cw-l,2-dicarboxylate the coupled a-bonded complex (5) is obtained. 12 Photochemical reaction (X > 370 nm) between [M 3 (CO) 12 ] and 5,6-dimethylidene-7-oxabicyclo-[2.2.1]hept-2-ene gives exo-[M (CO) 4 ] complexes (6) in poor yield; a bis(ligand)Ru(CO) 3 complex is obtained by use of pyrex-filtered UV irradiation. The uncomplexed conjugated diene in the complexes is more reactive towards Diels-Alder addition with dimethyl acetylenedicarboxylate than it is in the f r e e hydrocarbon.…”

“…Bicycloocta-2,7-dienyl reacts with [Ru 3 (CO) 12 ] to give initially a Ru(CO) 3 complex (38) of the isomer bicycloocta-l,7-dienyl, which reacts further with [Ru 3 (CO) 12 ] to give a mixture o f the isomeric, hydrogenated ruthenacyclopentadienes (39) and (40). 12 ] in the presence of 2,3-dimethylbutadiene as hydrogen acceptor to give the ruthenacyclopentadiene (42).…”