General Approach to the Synthesis of Prochiral Atropisomeric Biaryls

Table 2

Optimisation of the reaction conditions of synthesis of 3-methyl-2-(2′-methoxyphenyl)pyridine (27).

Entry	Substrate	Solvent	Base	Catalyst	Yield [%]^a
1	17	Toluene/ethanol	Na2CO4 (aq.)	[Pd(PPh3)4]	trace
2	5	DMF (anh.)	K3PO4 (anh.)	[Pd(PPh3)4]	46
3	5	DMF (anh.)	K3PO4⋅H2O	[Pd(PPh3)4]	49
4	5	DMF	K3PO4⋅H2O	[Pd(PPh3)4]	57
5	5	DMF	K3PO4⋅H2O	Ph3P, Pd (AcO)2	54
6	5	MeOH	K3PO4⋅H2O	[Pd(PPh3)4]	42^b
7	17	MeOH	K3PO4⋅H2O	[Pd(PPh3)4]	59
8	5	DMF/MeOH	K3PO4⋅H2O	[Pd(PPh3)4]	66
9	5	MeOH/H2O	AgOAc	[Pd(PPh3)4]	0
10	5	MeOH/H2O	Ag2CO3	[Pd(PPh3)4]	0

aReactions were carried out under argon atmosphere, under gentle reflux. bReaction run at 130°C in sealed vessel.