Preparation and Characterization of Pd Modified TiO₂ Nanofiber Catalyst for Carbon–Carbon Coupling Heck Reaction

Table 2

Pd-TiO₂ catalyzed Heck reaction of bromobenzene and styrene.

Entry	Base	Solvent	Cat (Pd, mol%)	Temp (°C)	Time (h)	Conversion
	Et3N	Toluene	0.05	140	6	19
	Et3N	MeOH	0.05	140	6	11
	Et3N	EtOH	0.05	140	6	17
	Et3N	DMF	0.05	140	6	33.9
	K2CO3	DMF	0.05	140	6	30.1
	NaOAc	DMF	0.05	140	6	41.9
	Na2CO3	DMF	0.05	140	6	27.3
	NaOAc	DMF	0.05	140	6	41.9
	NaOAc	DMF	0.1	140	6	61.2
	NaOAc	DMF	0.2	140	6	89.7
	NaOAc	DMF	0.2	100	6	56.3
	NaOAc	DMF	0.2	120	6	73.0
	NaOAc	DMF	0.2	140	6	89.0
	NaOAc	DMF	0.3	140	6	89.0
	—	DMF	0.2	140	6	0
	NaOAc	DMF	—	140	6	0
	NaOAc	DMF	TiO2	140	6	3
	NaOAc	DMF	Pd(acac)2	140	6	14

Reaction conditions: styrene (1.2 mmol), bromobenzene (1.0 mmole), base (1.0 mmole), and solvent (4 mL) based on average results (reaction carried out thrice for reproducibility).