Alkyne Trifunctionalization via Divergent Gold Catalysis: Combining π-Acid Activation, Vinyl–Gold Addition, and Redox Catalysis

Here we report the first example of alkyne trifunctionalization through simultaneous construction of C–C, C–O, and C–N bonds via gold catalysis. With the assistance of a γ-keto directing group, sequential gold-catalyzed alkyne hydration, vinyl–gold nucleophilic addition, and gold(III) reductive elimination were achieved in one pot. Diazonium salts were identified as both electrophiles (N source) and oxidants (C source). Vinyl–gold(III) intermediates were revealed as effective nucleophiles toward diazonium, facilitating nucleophilic addition and reductive elimination with high efficiency. The rather comprehensive reaction sequence was achieved with excellent yields (up to 95%) and broad scope (>50 examples) under mild conditions (room temperature or 40 °C).