Table 2.

Three-component reaction of aldehydes, urea, and acetoacetate for the asymmetric synthesis of DHPMs^[a]

Entry	R	Product	Yield [%][b]	ee [%][c]
1	Ph	11a	81	73
2	4-MeC6H4	11b	53	69
3	4-MeOC6H4	11c	71	51
4	2-MeC6H4	11d	53	53[d]
5	4-FC6H4	11e	61	73
6	4-ClC6H4	11f	63	76
7	4-BrC6H4	11g	68	78
8	4-CNC6H4	11h	20	76
9	4-NO2C6H4	11i	14	72
10	3-NO2C6H4	11j	21	74
11	n-C6H13	11k	43	72

^[a]All reactions were conducted with compounds 8 (0.25 mmol), 9 (0.5 mmol), and 10 (1.25 mmol) in the presence of catalyst 1 (0.05 mmol, 20 mol %) and HCl (0.05 mmol, 20 mol %) in THF (1.5 mL) at 0 °C for 6 days.

^[b]Yield of the isolated product after column chromatography.

^[c]Unless otherwise noted, ee values were determined by the HPLC analysis on a ChiralCel OD-H column.

^[d]Determined by the HPLC analysis on a ChiralPak AD-H column.