Table 14.

(−)–Sparteine–promoted addition of n–BuLi to imine 4

entry	ligand	equiv	solvent	temp, °C	yield, %a	erb
1	12bc	2.6	toluene	−78	99	66.0:34.0
2	12bc	0.1	toluene	−78	39	56.5:43.5
3	12cc	1.0	i-Pr2O	−94	94	67.0:33.0
4	4	1.0	toluene	−78	91	60.5:39.5
5	4	1.0	i-Pr2O	−78	84	68.5:31.5
6	4	1.0	Et2O	−78	99	68.0:32.0
7	4	1.0	Et2O	−94	95	72.0: 28.0
8	4	0.2	Et2O	−78	89	63.5:26.5
9	4a	1.0	Et2O	−78	91	57.0:43.0

^aYield of chromatographically homogeneous material.

^bAll compounds have R configuration. Determined by CSP- HPLC analysis.