Table 2.

Further screening results of the model reaction.

Entrya	Catalyst loading (mol %)	Conc. (M)	T (°C)	Time (h)	Yieldb (%)	eec (%)
1	0.1	0.2	rt	72	–	–
2	0.5	0.2	rt	40	81	82
3	1	0.2	rt	23	93	83
4	2	0.2	rt	4	85	79
5	5	0.2	rt	6	95	76
6	10	0.2	rt	3	83	69
7	1	0.05	rt	72	–	–
8	1	0.1	rt	72	–	–
9	1	0.15	rt	26	>99	79
10	1	0.25	rt	25	>99	78
11	1	0.3	rt	20	91	79
12	1	0.4	rt	19	>99	75
13d	1	0.2	rt	72	–	–
14e	1	0.2	rt	41	91	79
15f	1	0.2	rt	19	90	78
16	1	0.2	0	40	96	73
17	1	0.2	−20	41	97	68
18	1	0.2	−40	49	90	62

^aUnless stated otherwise, all reactions were performed with a 1:2 ratio of trans-chalcone/naphthalene-1-thiol in THF, in the presence of organocatalyst 5 at the indicated temperature. ^bIsolated yields. ^cDetermined by chiral HPLC analysis, AD-H column, 99:1 hexane/isopropanol, 0.8 mL/min, 220 nm. ^dThe reaction was carried out using a 1:1 ratio of trans-chalcone/naphthalene-1-thiol. ^eThe reaction was carried out using a 1:1.5 ratio of trans-chalcone/naphthalene-1-thiol. ^fThe reaction was carried out using a 1:3 ratio of trans-chalcone/naphthalene-1-thiol.