Ligand-modified Monsanto process

Rhodium-Catalyzed Methanol Carbonylation the Ligand-Modified Monsanto Process... 

Methanol carbonylation has been the subject of numerous reviews [6-17], including the seminal mechanistic studies by Denis Forster at Monsanto. This chapter does not seek to repeat all the information included in those reviews, but instead is focused on the important recent advances in process development and mechanistic understanding along with recent research efforts to identify new ligand-modified, supported, or promoted catalysts. The increasing use of computational methods to model catalytic mechanisms and potential alternative catalytic routes to acetic acid are also summarized. 

Detailed mechanistic and theoretical analysis of the key mechanistic steps of the Cativa process, for the Cativa process See Ref 257,257a that is, the iridium-based catalytic carbonylation of methanol to acetic acid, have allowed several groups, " particularly Haynes and co-workers, to unravel the mechanism of the catalytic process. Ir(l) complexes [Ir(CO)(L-L)I] (LL = dppms, dppe, dppmo) provided important mechanistic information about the influence of stereoelectronic ligand effects on the organometallic reactivity of modified metal centers with Mel. The carbonylation of methanol promoted by iridium and rhodium complexes which is at the basis of both Cativa and Monsanto processes for the synthesis of acetic acid will be described in detail in a different chapter of this volume. 

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