Table 1. Screening of reaction conditions for the Pd-catalyzed indole-to-carbazole APEX reaction of N-methylindole (1a) and diiodobiphenyl (2a).

Entry	Pd cat.	Ag salt	Temp. (°C)	Yield a (%)
1	Pd(OAc)2	Ag2CO3 (3.0 eq.)	80	54
2	Pd(OPiv)2	Ag2CO3 (3.0 eq.)	80	61
3	PdCl2	Ag2CO3 (3.0 eq.)	80	3
4	PdI2	Ag2CO3 (3.0 eq.)	80	2
5	Pd(PPh3)4	Ag2CO3 (3.0 eq.)	80	4
6	Pd(OCOCF3)2	Ag2CO3 (3.0 eq.)	80	0
7	Pd(CH3CN)4(BF4)2	Ag2CO3 (3.0 eq.)	80	0
8	Pd(OPiv)2	Ag2CO3 (1.5 eq.)	80	78 (66) c
9	Pd(OPiv)2	AgOAc (3.0 eq.)	80	33
10	Pd(OPiv)2	AgOPiv (3.0 eq.)	80	0
11	Pd(OPiv)2	AgOCOCF3 (3.0 eq.)	80	0
12	Pd(OPiv)2	Ag2CO3 (1.5 eq.)	100	57
13 b	Pd(OPiv)2	Ag2CO3 (1.5 eq.)	100	58
14	None	Ag2CO3 (1.5 eq.)	80	0
15	Pd(OPiv)2	None	80	0

^aYield was determined by ¹H NMR analysis using dodecane as an internal standard.

^bReaction time was 1 h.

^cIsolated yield in the parenthesis. Piv = pivaloyl.