Table 3.

Optimization of the coupling reaction of 4-bromo-1-ethyl-1H-pyrrolo[2,3-b]pyridine (1d) with phenylmethanamine (4a).^a

Entry	Pd-catalyst (5 mol %)	Ln	Base	Time (h)	Yield (%)b
1	Pd2(dba)3	L1	Cs2CO3	1	93
2	Pd2(dba)3	L1	K2CO3	3	85
3	Pd2(dba)3	L2	Cs2CO3	6	60
4	Pd2(dba)3	L3	Cs2CO3	6	62
5	Pd2(dba)3	L4	Cs2CO3	24	0
6	Pd(OAc)2	L1	Cs2CO3	24	20
7	Pd(OAc)2	L1	K2CO3	24	15
8	Pd(OAc)2	L1	NaOt-Bu	24	23
9	Pd(OAc)2	L1	K3PO4	24	20
10	Pd(OAc)2	L2	Cs2CO3	24	18
11	Pd(OAc)2	L3	Cs2CO3	24	17
12	Pd(OAc)2	L4	Cs2CO3	24	0

^aReactions of 1-ethyl-4-bromo-1H-pyrrolo[2,3-b]-pyridine (1d) (1.0 mmol) with phenylmethanamine (4a) (1.2 mmol) were performed in a sealed Schlenk tube at 100 °C in dioxane (2 mL) by using Pd catalyst (5 mol %), ligand (10 mol %) and base (1.5 mmol). ^bYields reported are isolated yield.