Highly Efficient Michael Addition Reaction of Amines Catalyzed by Silica-Supported Aluminum Chloride

Figures & data

Scheme 1 Michael addition of aromatic and aliphatic amines with methyl acrylate.

Table 1. Michael addition of amines catalyzed by silica-supported aluminum chloride under solvent-free conditions

Entry	Amine	Michael acceptor	Product	Time (h)	Yield (%)
1	PhNH2			4.0	Quant.
2				1.5	Quant.
3			N. R
4				4.0	97
5				5.5	85
6				8.0	50
7				2.0	Quant.
8				2.0	Quant.
9				4.0	52
10				2.0	Quant.
11	PhNH2			6.0	75
12				1.5	63
13				6.5	90
14				7.0	60
15				2.0	86
16				5.0	40
17				2.0	72.5
18				10.0	15
19	PhNH2			4.0	Quant. ^a
20				7.0	Quant. ^a, ^b
21				2.0	90
22				5.0	44
23				2.0	77.5
24				8.0	Quant. ^b, ^c
25				20.0	Quant.

Table 2. Michael addition reaction of methyl acrlylate with aniline in protic and aprotic solvent

Solvent	Yield (%)
C2H5OH	28
H2O	50
ClCH2CH2Cl	89
PhCH3	55
CH3CN	83

Table 3. Activity of the recovered silica-supported aluminum chloride ^a

Run	Yield (%)
1	97
2	69
3	65

Scheme 2 Competition reaction of aniline and morpholine with methyl acrylate.