Scheme 5.

Coupling with five-membered substrates^a

^a Conditions: HetArX (1 mmol), NH₃ (3 mmol), NaO^tBu (1.4 mmol), 3c (2 mol %), L4 (2 mol %), dioxane (10 mL, 0.10 M), 20–24 h; isolated products, average of two runs. ^b Conditions: HetArX (0.25 mmol), NH₃ (0.75 mmol), NaO^tBu (0.35 mmol), Pd₂dba₃ (1 mol %), L6/L3/L4 (4 mol %), dioxane (2.5 mL, 0.10 M), 120 °C, 20 h; ¹H NMR yield of crude product. ^c 3c and L4 (5 mol %), dioxane (7 mL, 0.143 M). ^{d 1}H NMR yield of crude product. ^e 3b and L7 (2 mol %).