Fig. 5: Late-stage modification of natural products and medicinally relevant molecules.

Reaction conditions: pyridinium salt (0.3 mmol), alkyne (0.45 mmol), NiCl2·6H2O (10 mol%), L4 (10 mol%), K3PO4 (1.3 equiv), THF (1.5 mL), 80 oC. Isolated yields. For 7, 9, 15, 16, 17, 18, 19 and 20, reactions were conducted in DMF (1.5 mL).