Table 3. Optimization of Reaction Conditions for N-Alkylation of Aniline with Benzyl Alcohol^a.

entry	cat.	base	yield (%)
1	2a	tBuOK	55
2	2b	tBuOK	80
3	2c	tBuOK	72
4	3a	tBuOK	40
5	3b	tBuOK	67
6	3c	tBuOK	67
7	2b	Cs2CO3	62
8	2b	K2CO3	33
9	2b	KOH	58
10b	2b	tBuOK	93
11c	2b	tBuOK	48
12d	[IrCl2Cp*]2	tBuOK	22
13e	1b/[IrCl2Cp*]2	tBuOK	42
14		tBuOK	trace
15f	2b	tBuOK	69
16	2d	tBuOK	62
17	3d	tBuOK	58
18	2e	tBuOK	64

^aReaction conditions: Aniline (1.0 mmol), benzyl alcohol (1.5 mmol), ^tBuOK (1.5 mmol), cat. (1.0% mol), 20 h, 120 °C, air atmosphere.

^b24 h.

^c(0.5% mol).

^dOnly [IrCl₂Cp*]₂ complex was used as the catalyst.

^eIn situ generated catalytic system with 1b carbene precursor and [IrCl₂Cp*]₂ was used.

^fUnder argon atmosphere. Yields were determined using ¹H NMR spectroscopy.