Table 2. The role of the base ^a .

Entry	Base (equiv.)	11 (equiv.)	12 b (%)	Notes
1	KHMDS (2.0)	2.0	81	—
2	NaHMDS (2.0)	0.10	80	—
3	KOtBu (2.0)	0.10	60	Side-products observed
4	KHMDS (0.5)	—	—	Only 1a and 1d observed
5	NaHMDS (0.5)	—	24	Side-products observed
6 c	KHMDS (0.5)	—	—	Only 1a and 1d observed

^aConditions: benzyl chloride (0.24 mmol, 1.2 equiv., or none), imine 1a (0.2 mmol, 1.0 equiv.), base (0.4 mmol or 0.1 mmol, 2.0 equiv. or 0.5 equiv.), toluene (0.6 mmol), 45 °C, 3 hours.

^bCalculated by NMR analysis using dimethyl malonate as an internal standard.

^cReaction performed in the presence of 5% [Ni(COD)₂]/10% IPr.