When thinking about what a mechanism might look like, the first thing to note is that we are using a strong base (NaOH). That begs a question: what’s the most acidic proton here? Hint: it’s not the C-H attached to the aldehyde! (that would result in an acyl anion, which is ...
63–66 The mechanism is believed to proceed first through the formation of a CuF(tol-BINAP) precatalyst that is then able to react with the silyl dienolate 101 to form a copper dienolate 102 (observed by IR), which is actually the catalytic species. The copper dienolate is then trapped ...