Table 3. threo-Selective three-component reactions catalyzed by [Rh(COD)Cl]₂ ^a .

Entry	R1/R2	Ar1	Ar2	Yield (%)	dr
1	Bn/Et	o-MeOC6H4	p-NO2C6H4	4a, 65	12 : 1
2	Bn/Et	o-MeOC6H4	o-NO2C6H4	4d, 50	2 : 1
3	Bn/Et	o-MeOC6H4	p-CNC6H4	4e, 30	7 : 1
4	Bn/Et	o-MeOC6H4	p-BrC6H4	4f, 50	6 : 1
5	Bn/Et	o-MeOC6H4	m-BrC6H4	4g, 56	3 : 1
6	Bn/Et	o-MeOC6H4	C6H5	4h, 18	4 : 1
7	Bn/Et	o-MeOC6H4	p-MeOC6H4	Trace	—
8	Bn/Et	2,4,6-CH3C6H2	p-NO2C6H4	4i, 31	3 : 1
9	Bn/Et	C6H5	p-NO2C6H4	4j, 55	>20 : 1
10	Bn/Et	p-EtOC6H4	p-NO2C6H4	4k, 45	2 : 1
11	Bn/Et	3,4,5-MeOC6H2	p-NO2C6H4	4l, 44	4 : 1
12	Bn/Et	p-MeOC6H4	p-NO2C6H4	4m, 45	10 : 1
13	Bn/Et	o-EtOC6H4	p-NO2C6H4	4n, 60	10 : 1
14	n-Pr/Et	2,4,6-CH3C6H2	p-NO2C6H4	4o, 52	>20 : 1
15	H/But	o-MeOC6H4	p-NO2C6H4	4p, 41	2 : 1

^aThe reactions were carried out in the same way as those in Table 1.