Table 2. Comparison of Reaction Times and TONs of the CuNP-Catalyzed TH of Nitrobenzene under Conventional, Oil Bath, MW, MW/US Irradiation, and Continuous-Flow Conditions.

reaction conditions	reaction time	Cu cat	TON	ref
nitrobenzene, glycerol, KOH (2 equiv), CuNPs, 130 °C, oil bath	1 h	5 mol %	20	(14)
nitrobenzene, glycerol, KOH (2 equiv), CuNPs, 130 °C, MW	20 min under MW	2.5 mol %	40	(14)
	10 min under MW/US	2.5 mol %	40	(14)
nitrobenzene (130 mmol), EG, KOH (2 equiv), CuNPs/Celite (500 mg 5% w/w), 130 °C, 0.03 uL/min flow chemistry	3.04 min	0.3 mol % 6.7474 m2 (Cu surface area)	333	this work