Table 1.

Optimization of palladium-catalyzed C–H arylation of 1.

Entry	Catalyst	Ligand	Base	Temperature	Time	Solvent	Yield
1	CuI	–	t-BuLi	120 °C	24 h	DMF	10% a
2	Pd(OAc)2	–	n-Bu4NOAc	120 °C	24 h	NMP	15% a
3	Pd(OAc)2	–	n-Bu4NOAc	120 °C	20 h	DMF	21% a
4	Pd(OAc)2	–	Cs2CO3	120 °C	20 h	DMF	6% a
5	Pd(OAc)2	–	K2CO3	120 °C	20 h	DMF	31% a
6	Pd(OAc)2	PPh3	K2CO3	120 °C	20 h	DMF	75% a 68% b
7	Pd(OAc)2	P(o-Tol)3	K2CO3	120 °C	20 h	DMF	70% a
8	Pd(OAc)2	PPh3	K2CO3	100 °C	24 h	DMF	77% a
9	Pd(OAc)2	P(n-Bu)3	K2CO3	100 °C	24 h	DMF	<5% a
10	Pd(OAc)2	PCy3	K2CO3	100 °C	24 h	DMF	20% a
11	Pd(OAc)2	P(2-furyl)3	K2CO3	100 °C	24 h	DMF	29% a
12	Pd(OAc)2	Cy-JohnPhos	K2CO3	100 °C	24 h	DMF	19% a
13	Pd2(dba)3 c		K2CO3	100 °C	24 h	DMF	7% a
14	Pd(OAc)2	PPh3	K2CO3	120 °C	20 h	toluene	95% a 89% b

^a Estimated by HPLC; ^b Isolated yield; ^c 5 mol % catalyst.