RESUMEN
1,6-Conjugate additions of in situ generated δ-CF3-δ-substituted p-quinone methides have been achieved with a variety of heteronucleophiles under mild conditions, which led to facile and practical construction of fully substituted carbon centers including a heteroatom and a CF3 group. In particular, it was revealed that some amines themselves worked for efficient cleavage of the TBS protective group, and addition of a catalytic amount of an appropriate Brønsted acid was found to sometimes improve the progress of the desired process.
RESUMEN
New and successful results for the construction of new and structurally interesting compounds are reported via N-heterocyclic carbene (NHC)-catalyzed 1,6-conjugate additions of a variety of aldehydes to δ-CF3-δ-substituted p-quinone methides generated in situ, and the products are used for the 1,2-addition reactions of appropriate metal nucleophiles, enabling us to furnish highly diastereoselective products with a unique successive quaternary carbon-tertiary alcohol framework (up to dr = >99 : 1).
RESUMEN
Development of a new synthetic method for the construction of quaternary centers with a trifluoromethyl group was realized by way of 1,6-addition of various nucleophiles including active methylene compounds to highly reactive δ-trifluoromethylated p-quinone methides generated in situ from the corresponding tertiary carbonates with a catalytic amount of an appropriate base.