Table 1. Optimization of the conditions for Ugi multicomponent reaction^a.

No.	Lewis acid	Isocyanide, R1	Solventb	Yield,d6(a)(i)	Yield,d7(a)(i)
1	BF3·Et2O	Bn	MeOH	21	—
2	InCl3	Bn	MeOH	—	11
3	p-TsOH	Bn	MeOH	5	1
4	Sc(OTf)3	Bn	MeOH	—	8
5	Mg(OTf)2	Bn	MeOH	—	10
6	Cu(OTf)2	Bn	MeOH	2	6
7	In(OTf)2	Bn	MeOH	5	11
8	BF3·Et2O	t-Octyl	MeOH	67	—
9	BF3·Et2O	t-Butyl	MeOH	11	—
10	BF3·Et2O	t-Octyl	EtOH	32	10
11	BF3·Et2O	t-Octyl	t-BuOH	24	18
12	BF3·Et2O	t-Octyl	MeOHc	44	—
13	BF3·Et2O	t-Butyl	EtOH	31	7

^a3(a), 1.0 equiv.; 4(i), 1.0 equiv.; 5, 1.0 equiv.; Lewis acid, 3.0 equiv.; solvent, 10 mL.

^bTemp., RT.

^cTemp., 60 °C.

^dDiastereomeric mixture.