Optimization of coupling of ketimine 1a and amide 2a^a,b.

Entry	Base (equiv.)	Solvent	Conc. [M]	Yield (%)b
1	LiOtBu (1.5)	DMSO	0.2	56 (dr = 1 : 1)
2	NaOtBu (1.5)	DMSO	0.2	61 (dr = 1 : 1)
3	KOtBu (1.5)	DMSO	0.2	65 (dr = 1.3 : 1)
4	LiHMDS (1.5)	DMSO	0.2	59 (dr = 1 : 1)
5	NaHMDS (1.5)	DMSO	0.2	89 (86)c (dr = 1.2 : 1)
6	KHMDS (1.5)	DMSO	0.2	65 (dr = 1 : 1)
7	NaHMDS (1.5)	THF	0.2	0
8	NaHMDS (1.5)	DMF	0.2	0
9	NaHMDS (1.5)	CPME	0.2	0
10	NaHMDS (1.5)	MTBE	0.2	0
11	NaHMDS (1.5)	MeCN	0.2	0
12	NaHMDS (1.5)	DMSO	0.1	78 (dr = 1 : 1)
13	NaHMDS (1.5)	DMSO	0.05	68 (dr = 1 : 1)
14	NaHMDS (2.0)	DMSO	0.2	72 (dr = 1 : 1)
15d	NaHMDS (1.5)	DMSO	0.1	22 (dr = 1 : 1)
16e	NaHMDS (1.5)	DMSO/THF = 1 : 1	0.1	8 (dr = 1 : 1)

^aReaction conditions: 1a (0.1 mmol, 1.0 equiv), 2a (0.2 mmol, 2.0 equiv), base, rt., 3 h.

^bAssay yield (AY) determined by ¹H NMR spectroscopy of the crude reaction mixture using C₂H₂Cl₄ as an internal standard.

^cIsolated yield after chromatographic purification.

^d60 °C.

^e0 °C.