Table 1.

Catalyst screening and reaction condition optimization for the two-component reaction^a

Entry	Catalyst	Solvent	Time (h)	Yieldb (%)	eec (%)
1	1	CH2Cl2	27	80	23
2	2	CH2Cl2	24	92	96
3	3	CH2Cl2	24	91	65
4	4	CH2Cl2	27	80	0
5	5	CH2Cl2	27	88	14
6	6	CH2Cl2	24	79	11
7	7	CH2Cl2	27	96	10
8	8	CH2Cl2	27	92	22d
9	9	CH2Cl2	24	83	6d
10	2	CHCl3	20	87	92
11	2	THF	20	74	60
12	2	Et2O	20	94	62
13	2	Benzene	20	79	82
14	2	CH3CN	20	91	24

^aAll reactions were carried out with 10a (0.10 mmol), 11a (0.10 mmol), and the catalyst (5 mol %) in the indicated solvent (2.0 mL) at rt.

^bYield of isolated product after chromatography.

^cDetermined by HPLC analysis on a ChiralPak AS column.

^dThe S enantiomer was obtained as the major product.