Fig. 5: Catalysis in air.
From: Highly active alkyne metathesis catalysts operating under open air condition
a Open-air alkyne metathesis using catalyst VIII-d. The alkyne metathesis was performed in an open flask at 70 °C in the absence of molecular sieves. The activated catalyst was concentrated to dryness using a rotavap. The whole process took approximately 40 min. b Comparison of the catalytic activities of VIII-d and III in air and argon. Conditions for VIII-d in open air: 0.1 mmol substrate, 0.003 mmol catalyst (3 mol%), 3 mL CCl4, 70 °C, 30 min; Conditions for VIII-d in argon: 0.1 mmol substrate, 0.003 mmol catalyst (3 mol%), 3 mL CCl4, 150 mg MS 5 Å, 70 °C, 30 min. Conditions for III in open air: 0.1 mmol substrate, 0.002 mmol catalyst (2 mol%), 3 mL toluene, 70 °C, 30 min; Conditions for III in argon: 0.1 mmol substrate, 0.002 mmol catalyst (2 mol%), 3 mL toluene, 100 mg MS 5 Å, 70 °C, 30 min. c Stability of the catalyst dispersed in paraffin wax and stored on a bench top under ambient conditions. 4-Methoxylpropynylbenzene was used as the substrate and the reaction conversion was monitored at different time intervals in air.
