. 2019 Mar 29;24(7):1231. doi: 10.3390/molecules24071231

Table 2.

Fine-tuning of catalyst amount, reaction temperature, and cellulose nanofiber quantity ^a.

graphic file with name molecules-24-01231-i002.jpg

Entry	Conditions	TOCN	Yield (%) ^b	syn:anti^c	ee for syn (%) ^c
1	5 mol% catalyst, rt	−	37	87:13	29
1	5 mol% catalyst, rt	+	74	93:7	39
2	15 mol% catalyst, rt	−	58	69:31	26
2	15 mol% catalyst, rt	+	77	69:31	39
3	7.5 mol% catalyst, 0 °C	−	9	77:23	19
3	7.5 mol% catalyst, 0 °C	+	23	74:26	39
4 ^d	7.5 mol% catalyst, 40 °C	−	66	94:6	32
4 ^d	7.5 mol% catalyst, 40 °C	+	91	94:6	42
5	Substrate/TOCN (mg/mg) 74.6/25	+	51	92:8	41
6	Substrate/TOCN (mg/mg) 74.6/50	+	66	94:6	43
7	Substrate/TOCN (mg/mg) 74.6/100	+	88	90:10	41
8	Substrate/TOCN (mg/mg) 74.6/150	+	63	71:29	41
9	Substrate/TOCN (mg/mg) 74.6/200	+	43	83:17	43

^a Unless otherwise noted, the reaction was performed using cyclohexanone (1a) (4 mL, excess), trans-β-nitrostyrene (2a) (74.6 mg, 0.50 mmol), (S)-proline (7.5 mol%), and TOCN-Na (100 mg dry weight) in a mixture of DMF (14 mL) and MeOH (2 mL). Aqueous medium of TOCN suspension was replaced with MeOH by repetitive centrifugation prior to reaction; ^b Isolated yield; ^c Determined by chiral stationary phase SFC analysis; ^d Stirred for 11 h.