The Baylis–Hillmann (B–H) reaction 11 allows the direct preparation of α-methylene-β-hydroxyl carbonyl compounds from the corresponding α,β-unsaturated carbonyls and aldehydes. Applications to total synthesis 12 and mechanistic studies 13 of this reaction are also well documented. Surprisingly, relatively few examples of the intramolecular B–H reaction have been reported so far. 14 Certain studies 15 revealed that the use of dual catalyst systems can increase ...
