Question

What is the best explanation for why alkyl lithium and Grignard reagents react by direct addition to α,β-unsaturated carbonyl compounds, while lithium dialkyl cuprates react by conjugate addition

a. The additional steric bulk of lithium dialkyl cuprates makes it hard to do direct addition

b. The initial addition of the lithium dialkyl cuprate is reversible, so the reaction is under thermodynamic control and thus gives the most stable end product

c. Lithium dialkyl cuprates are more reactive, so they can react with the less significant the partial positive charge on the β carbon

d. Mg and Li prefer to interact with the O, so they react with the C atom closer to it

Answer 1