Organometallic Catalysis: Cross-Coupling Reactions

The Suzuki-Miyaura coupling uses a Pd catalyst to couple arylboronic acids with aryl halides. (a) Draw the complete catalytic cycle. (b) Explain the role of the base in the reaction. (c) Why is this reaction preferred over the Stille coupling for pharmaceutical synthesis? (d) How does the choice of ligand (e.g., PPh3 vs. SPhos) affect the oxidative addition step? (e) Predict the product of the coupling between 4-bromotoluene and phenylboronic acid.