Table 1. Development of a Diastereo- and Enantioselective BisAMidine-Catalyzed Aryl Nitromethane Addition to Azomethine^a.

entry	BisAMidine	temp (°C)	TfOH (equiv)	dr	ee (%)	yieldb (%)
1	5c	−20	1	13:1	64	81
2	5c	−20	0	10:1	65	99
3	6c	−20	1	7:1	80	87
4	6c	−20	0	6:1	72	98
5	7c	−20	1	5:1	58	95
6	7c	−20	0	6:1	63	96
7	8a	−78	1	5:1	85	99
8	8a	−78	0	9:1	86	97
9	8a	−20d	0	6:1	83	99
10	8b	−78	0	13:1	87	99
11	8c	−78	0	16:1	89	99
12	8d	−78	0	13:1	91	97

^aReactions employed 1 equivalent of α-bromo nitroalkane (0.2 M in THF), with NIS added as the final reagent at 25 °C.

^bIsolated yields.

^c2 Equivalents of imine used.

^d1.2 Equivalents of imine used.