127261-08-9Relevant academic research and scientific papers
Novel Basic Ligands for the Homogenous Catalytic Methanol Carbonylation, XXIV. Rhodium Complexes with (Ether-Phosphane) Ligands of Different Basicity and their Influence on the Methyl Migration
Lindner, Ekkehard,Norz, Hubert
, p. 1493 - 1498 (2007/10/02)
1-O)> (3) is obtained from 2 (1) and the (ether-phosphane) ligand P1-O (2) 1-O=Ph2PCH2OCH3>. 3 reacts with AgSbF6 to form the cationic η2-P1-Orhodium complex 1-O)> (4).Addition of another ligand P2-O (5) 2-O=Pr2PCH2C4H7O> to 4 affords the bis(ether-phosphane)rhodium complex 1-O)(P2-O)> (6) with two different ether-phosphanes.In 6 COD is displaced by CO to give 1-O)(P2-O)Rh(CO)3> (7).The 31P NMR spectrum of 7 shows a temperature dependence.When a THF solution of compound 7 is flushed with argon it undergoes elimination of carbon monoxide to form 1-O)(P2-O)Rh(CO)> (10), containing a bidentate coordinated P2-O ligand (5).The reaction is reversible.Oxidative addition of CH3I to 10 results in the formation of a 1:1 mixture of the acyl complexes 1-O)(P2-O) Rh(I)(C(O)CH3)> (8) and 1-O)(P2-O)Rh(I)(C(O)CH3)> (9), the reactive intermediate 1-O)(P2-O)Rh(I)(CH3)(CO)> (11) not being observed.Formation of either 8 or 9 depends on the S or R configuration of the asymmetric C-atom in 5.On cleaving one or two Rh-O bonds the back reaction to 7 occurs. - Key words: Methanol Carbonylation, Ether-Phosphanes, Rhodium Complexes
