35. Transition Metals

Predict the product of the following Sonogashira coupling reactions.

(b)

Suggest two coupling partners that could be used to synthesize the compounds shown making the indicated C―C bonds.

(a)

The trimethylsilyl (TMS) group, used as a protecting group for alcohols, can also be used a protecting group for terminal alkynes. Show how TMS-acetylene could be used to link together two aryl halides using the Sonogashira reaction. [Hint: Deprotection of the TMS-acetylene can be done using KF in H₂O.]

The coupling of an alkyne with an aryl halide in the presence of a palladium catalyst and triethylamine is called a Sonogashira reaction. What reactants couple to form this product?

Determine compounds A, B, and C from the following reaction sequence.

Determine the product from the following Sonogashira Reaction.

Predict the product of the following Sonogashira coupling reactions.

(a)