Table 2. Substrate Scope of Indoles and Enals Converted to the Corresponding Friedel–Crafts Products 3a–3i by LmrR_pAF and LmrR_pAF_RGN^a.

entry	product	catalyst	yield (%)b	ee (%)c
1	3a	A	42 ± 4	45 ± 0
2	3a	B	74 ± 2	87 ± 0
3d	3b	A	24 ± 1	58 ± 0
4d	3b	B	34 ± 6	83 ± 2
5	3c	A	76 ± 7	33 ± 1
6	3c	B	95 ± 7	58 ± 1
7	3d	A	3 ± 0	20 ± 1
8	3d	B	4 ± 1	13 ± 9
9e,f	3d	LmrR	<1	-
10g	3e	A	10 ± 1	50 ± 0
11g	3e	B	27 ± 2	89 ± 1
12g	3f	A	16 ± 1	41 ± 0
13g	3f	B	31 ± 3	89 ± 2
14g	3g	A	24 ± 2	55 ± 1
15g	3g	B	40 ± 3	89 ± 1
16f	3h	A	<1	-
17f	3h	B	<1	-
18	3i	A	62 ± 11	58 ± 0
19	3i	B	75 ± 9	82 ± 1
20g	3j	A	21 ± 1	66 ± 0 (S)h
21g	3j	B	18 ± 2	73 ± 1 (S)h

^aReaction conditions: LmrR variants (20 μM dimer concentration) in pH 6.5 buffer containing NaCl (150 mM) and NaH₂PO₄ (50 mM), 8 vol % DMF, [indole] = 1 mM, [enal] = 5 mM, reaction time 16 h, reactions conducted at 4 °C with mixing by continuous inversion in 300 μL total volume. Reduction with NaBH₄ (60 μL, 20 mg mL^–1 in 0.5 w/v% NaOH) afforded the alcohol products 3a–3i. For each entry, two independent experiments were conducted, each in duplicate. Errors are the standard deviation of the results thus obtained.

^bAnalytical yields determined using normal phase HPLC using 3-(3-hydroxypropyl)indole as internal standard.

^cEnantiomeric excess determined using chiral normal-phase HPLC (Chiracel OJ-H (3a), AS-H (3b, 3c, 3f), OD-H (3d, 3e, 3h, 3i, 3j) or OB-H (3g)).

^dReaction time 40 h.

^eLmrR was used in place of LmrR_pAF.

^fNo product could be detected.

^g50 μM artificial enzyme (concentration of dimer) was used, and reaction time was 64 h.

^hAbsolute configuration asigned by comparison of order of elution on chiral normal-phase HPLC with enantioenriched reference compound and the literature;¹⁸ see Supporting Information for details.