Table 2.

Investigation of reaction conditions under oxidant-free system^a.

Entry	Catalyst	Ligand	K3PO4 (equiv)	Solvent (mL)	Yield
1	Ru(dppf)(en)Cl2	—	2	0.2	22
2	Ru(PPh3)3Cl2	L1	2	0.2	40
3	Ru(PPh3)3Cl2	L2	2	0.2	66
4	Ru(PPh3)3Cl2	L3	2	0.2	73
5	Ru(PPh3)3Cl2	L3	1.5	0.2	66
6	Ru(PPh3)3Cl2	L3	2	0.3	71
7	Ru(PPh3)3Cl2	L3	2.5	0.3	64
8	Ru(PPh3)3Cl2	L3	2	0.5	70
9b	Ru(PPh3)3Cl2	L3	2	0.5	74
10b	Ru(PNN-1)(PPh3)Cl2	—	2	0.5	36
11b	Ru(PPh3)3Cl2	L4	2	0.5	32
12b	Ru(PNN-2)H(CO)Cl2	—	2	0.5	17
13b	Ru-PNP-1	—	2	0.5	73
14b	Ru-PNP-2	—	2	0.5	74

^aReaction conditions: 1a (0.7 mmol), 2a (0.2 mmol), Ru(PPh₃)₃Cl₂ (5 mol %), ligand (5 mol %), K₃PO₄, 2-Me-THF at 70 °C under N₂ atmosphere. See Supplementary Information (SI) for details. ¹H NMR yield was determined using 1,3,5-trimethoxylbenzene as an internal standard. A ‘trace’ amount of product was noted when the desired product was not clearly detected.

^b1a (0.6 mmol) was used.