Ring-Opening Polymerization of Lactones Catalyzed by Silicon-Based Lewis Acid

Table 1

Polymerization of ε-CL by silicon-based Lewis acids.

Run	Cat.	[M]0 : [BnOH]0 : [cat]	Solvent	[M]0 (mol/L)	Temp. (°C)	Time (h)	Yield (%)	Mn^a (kg/mol)	Đ^a
1	1a	100 : 0 : 1	Toluene	0.82	100	24	59	12	1.5
2	1a	100 : 1 : 1	Toluene	0.82	100	24	21	12	1.4
3	1a	100 : 2 : 1	Toluene	0.82	100	24	<1	—	—
4	1a	100 : 1 : 2	Toluene	0.82	100	24	84	12	1.5
5	1b	100 : 1 : 2	Toluene	0.82	100	24	67	6	1.8
6	2a	100 : 0 : 1	Toluene	0.82	100	24	46	6	2.0
7	3a	100 : 0 : 1	Toluene	0.82	100	24	<1	—	—
8	1a	100 : 0 : 1	Toluene	0.82	60	24	35	17	1.5
9	1a	100 : 0 : 1	Toluene	0.82	r.t.	24	<1	—	—
10	1a	200 : 0 : 1	Toluene	0.82	100	24	19	11	1.6
11	1a	50 : 0 : 1	Toluene	0.82	100	24	64	7	1.9
12	1a	100 : 0 : 1	Toluene	0.41	100	24	34	8	1.7
13	1a	100 : 0 : 1	Toluene	3.0	100	24	>99	15	2.7
14	1a	100 : 0 : 1	Bulk	—	100	1	>99	30	1.6
15	1a	100 : 0 : 1	Bulk	—	100	1/6	98	29	1.7
16	1a	30 : 0 : 1	Bulk	—	100	1/4	97	16	1.6
17	1a	300 : 0 : 1	Bulk	—	100	1/6	89	32	1.8
18	cat^ClH2	100 : 0 : 1	Bulk	—	100	1	<1	—	—

^aDetermined by GPC analysis calibrated with standard polystyrenes in THF.