Problems and exercisesThe Negishi, Stille and Kumada couplings
Exercise 1
Which organometallic reagent would you use to attach a vinyl group to an aryl triflate bearing a ketone and an ester, if you wish to avoid both boron and magnesium compounds? Give the conditions.
Exercise 2
Rank Grignard reagents, organozinc reagents and organostannanes according to (a) their reactivity towards an aldehyde and (b) their toxicity. What are the consequences for the choice of coupling?