Areneruthenium(II) complexes containing bulky phosphines with various functionalities as ligands

The dimeric starting materials [Ru(6-arene)Cl2]2(arene = mes, C6Me6) react with the functionalized phosphines Pri2PCH2X (X = CH2OMe, CO2Me) to give the mononuclear compounds [Ru(6-arene)(P-Pri2PCH2X)Cl2]3–6 which upon treatment with AgPF6 afford the chelate complexes [Ru(6-arene)(2P,O-Pri2PCH2CH2OMe)Cl]PF67, 8 and [Ru(6-arene){2P,O-Pri2PCH2C(O)OMe}Cl]PF69, 10, respectively. Complexes 7 and 8 react with CO and CNBut to yield the chiral-at-metal compounds [Ru(6-arene)(P-Pri2PCH2CH2OMe)(L)Cl]PF611–14. Treatment of 8 (arene = C6Me6) with Na2CO3 in the presence of water produces the carbonatoruthenium(II) derivative [Ru(6C6Me6)(2O,O-O2CO)(P-Pri2PCH2CH2OMe)]17. The reaction of 9(arene = mes) with KOBut leads to the formation of the uncharged phosphinoester enolate complex [Ru(6-mes)(2P,O-Pri2PCHC(O)OMe)Cl]18 which in benzene at room temperature smoothly rearranges to the phosphinomethanide isomer [Ru(6-mes)(2P,CPri2PCHCO2Me)Cl]19. The corresponding phosphinoacetate complexes [Ru(6-arene){2P,O-Pri2PCH2C(O)O}Cl] 21, 22 were obtained as the major products from 5 or 6 and NaH/Al2O3 in THF. Compound 18 reacts with water by ester hydrolysis to form 21 and with phenylisocyanate and diphenylketene to afford 24 and 25 by insertion of the heterocumulene into the enolate C–H bond. The molecular structures of 19 and 25 were determined crystallographically.