The catalytic transformation of 2-methylpropylbenzene and carbon dioxide into ibuprofen using a metal catalyst and co-catalyst involves several steps. Here is a step-by-step mechanism for this transformation:1. Activation of the metal catalyst: The metal catalyst, typically a transition metal like palladium Pd , is activated by a ligand, which can be a phosphine or an N-heterocyclic carbene NHC . This activation forms a metal complex that is capable of facilitating the subsequent reactions.2. Oxidative addition: The activated metal complex undergoes oxidative addition with 2-methylpropylbenzene, inserting the metal center into the carbon-hydrogen bond. This forms a metal-alkyl intermediate.3. Carboxylation: The metal-alkyl intermediate reacts with carbon dioxide CO2 to form a metal-carboxylate complex. This step is facilitated by the presence of a co-catalyst, such as a base or an alcohol, which can help to activate the CO2 molecule.4. Migratory insertion: The metal-carboxylate complex undergoes migratory insertion, in which the metal center migrates from the alkyl group to the aryl group, forming a new carbon-carbon bond. This results in the formation of a metal-aryl intermediate with a carboxylate group.5. Reductive elimination: The metal-aryl intermediate undergoes reductive elimination, in which the metal center is removed, and the carbon-carbon bond is formed between the aryl group and the carboxylate group. This step generates the ibuprofen molecule and regenerates the metal catalyst.6. Catalyst regeneration: The metal catalyst is regenerated by re-coordination with the ligand, allowing it to participate in further catalytic cycles.In summary, the catalytic transformation of 2-methylpropylbenzene and CO2 into ibuprofen involves a series of steps, including activation of the metal catalyst, oxidative addition, carboxylation, migratory insertion, reductive elimination, and catalyst regeneration. The use of a metal catalyst and co-catalyst enables this transformation to occur under mild conditions and with high selectivity for the desired product, ibuprofen.