Direct Benzylic C-H Etherification Enabled by Base-Promoted Halogen Transfer.

We disclose a benzylic C-H oxidative coupling reaction with alcohols that proceeds through a synergistic deprotonation, halogenation and substitution sequence. The combination of tert-butoxide bases with 2-halothiophene halogen oxidants enables the first general protocol for generating and using benzyl halides through a deprotonative pathway. In contrast to existing radical-based methods for C-H functionalization, this process is guided by C-H acidity trends.

Direct C-H Hydroxylation of -Heteroarenes and Benzenes Base-Catalyzed Halogen Transfer.

Hydroxylated (hetero)arenes are valued in many industries as both key constituents of end products and diversifiable synthetic building blocks. Accordingly, the development of reactions that complement and address the limitations of existing methods for the introduction of aromatic hydroxyl groups is an important goal. To this end, we apply base-catalyzed halogen transfer (X-transfer) to enable the direct C-H hydroxylation of mildly acidic -heteroarenes and benzenes.

Enantioselective Synthesis of the Guaipyridine Alkaloid (+)- and (-)-Cananodine.

Synthesis of both enantiomers of guaipyridine alkaloid cananodine was achieved. The stereocenter at C8 was set through an Evans alkylation, and the seven-membered carbocycle was constructed using an intramolecular Mizoroki-Heck reaction. Hydrogenation of an exomethylene set the C5 stereocenter.