The Journal of Organic Chemistry
Article
Here, 100 mg of rac-1o was used. Enantioenriched 1o (67 mg,
67% yield) was purified by preparative TLC (15/1 dichloro-
methane/methanol) as a yellow liquid: H NMR (400 MHz,
propanol/ethanolamine, flow rate of 0.5 mL/min, 230 nm UV
lamp, 25 °C, t1 = 7.5 min (major), t2 = 8.0 min; 96% ee.
Enantioenriched 1-(Thiophen-2-ylmethyl)-1,2,3,4,5,6,7,8-
octahydroisoquinoline.
1
CDCl3) δ 6.73−6.82 (m, 3H), 3.86 (s, 3H), 3.85 (s, 3H), 3.28
(d, J = 10.4 Hz, 1H), 2.92−3.06 (m, 2H), 2.71 (ddd, J = 11.9,
7.6, 5.1 Hz, 1H), 2.47 (dd, J = 13.6, 10.4 Hz, 1H), 2.06−2.18 (m,
1H), 1.81−2.00 (m, 5H), 1.36−1.79 (m, 5H); 13C{1H} NMR
(100 MHz, CDCl3) δ 148.9, 147.5, 132.3, 129.8, 128.6, 121.2,
112.3, 111.3, 58.7, 55.9, 55.9, 40.9, 38.4, 31.0, 30.4, 27.0, 23.3,
22.8; HRMS (ESI) m/z [M + H]+ calcd for C18H26NO2
D
288.1958, found 288.1958; [α]25 = −100.13 (c = 0.5,
Here, 100 mg of rac-1r was used. Enantioenriched 1r (74 mg,
74% yield) was purified by preparative TLC (15/1 dichloro-
MeOH); HPLC ChiracelOJ-H, 250 mm × 4.6 mm column,
95/5/0.5 hexane/2-propanol/ethanolamine, flow rate of 0.5
mL/min, 230 nm UV lamp, 25 °C, t1 = 11.0 min (major), t2 =
1
methane/methanol) as a yellow liquid: H NMR (400 MHz,
CDCl3) δ 7.18 (d, J = 5.0 Hz, 1H), 6.96 (dd, J = 5.1, 3.4 Hz, 1H),
6.86−6.92 (m, 1H), 3.35 (d, J = 12.7 Hz, 1H), 3.20 (dd, J = 14.7,
3.2 Hz, 1H), 3.04 (dt, J = 11.0, 5.2 Hz, 1H), 2.91 (dd, J = 14.7,
9.6 Hz, 1H), 2.79 (ddd, J = 12.1, 7.4, 5.1 Hz, 1H), 2.07−2.21 (m,
1H), 1.83−2.05 (m, 6H), 1.66−1.83 (m, 2H), 1.47−1.65 (m,
2H); 13C{1H} NMR (100 MHz, CDCl3) δ 142.0, 129.4, 129.2,
126.8, 125.9, 124.0, 58.6, 40.6, 33.1, 30.9, 30.5, 27.0, 23.2, 22.8;
HRMS (ESI) m/z [M + H]+ calcd for C14H20NS 234.1311,
12.5 min; 97% ee.
Enantioenriched 1-(3,4-Difluorobenzyl)-1,2,3,4,5,6,7,8-octa-
hydroisoquinoline.
D
found 234.1322; [α]25 = −148.09 (c = 0.5, MeOH); HPLC
ChiracelIC, 250 mm × 4.6 mm column, 95/5/0.5 hexane/2-
propanol/ethanolamine, flow rate of 0.5 mL/min, 230 nm UV
lamp, 25 °C, t1 = 8.5 min (major), t2 = 9.8 min; 97% ee.
Here, 113 mg of rac-1p was used. Enantioenriched 1p (95 mg,
84% yield) was purified by preparative TLC (15/1 dichloro-
methane/methanol) as a yellow liquid: H NMR (400 MHz,
CHAOCCH12‑C2-Catalyzed Deracemization of 1a at a Gram
Scale. To a suspension of freshly prepared wet cells of CHAO (11.5 g)
(washed with NaPi buffer) in NaPi buffer (50 mM, pH 7.5, 57.5 mL)
were added 1a (1.495 g, 5.8 mmol) and NH3·BH3 (5 equiv relative to
1a). The resulting reaction mixtures were stirred at 900 rpm and 35 °C
for 5 days. The pH of the reaction mixture was first adjusted to ∼5 by
the addition of HCl (1 N) and then to ∼9 by the addition of NaOH (3
M). The mixture was extracted with EtOAc (3 × 200 mL), and the
organic layer was dried over Na2SO4 and concentrated. The residue was
purified by flash column chromatography to afford products (S)-1a
(1.007 g, 67% yield): 1H NMR (400 MHz, CDCl3) δ 7.53 (d, J = 8.5
Hz, 2H), 7.24 (d, J = 8.6 Hz, 2H), 4.18 (s, 3H), 3.63 (d, J = 10.6 Hz,
1H), 3.25−3.46 (m, 2H), 3.10 (ddd, J = 12.0, 7.2, 5.1 Hz, 1H), 2.86 (dd,
J = 13.6, 10.6 Hz, 1H), 2.45−2.58 (m, 1H), 2.21−2.38 (m, 5H), 2.01−
2.17 (m, 5H); 13C{1H} NMR (100 MHz, CDCl3) δ 158.4, 132.3, 130.5,
130.4, 128.8, 114.3, 59.2, 55.6, 41.1, 38.2, 31.4, 30.8, 27.4, 23.6, 23.2;
1
CDCl3) δ 7.02−7.14 (m, 2H), 6.90−6.99 (m, 1H), 3.29 (d, J =
10.6 Hz, 1H), 2.95−3.06 (m, 2H), 2.76 (ddd, J = 12.1, 7.2, 5.2
Hz, 1H), 2.51 (dd, J = 13.7, 10.4 Hz, 1H), 2.06−2.19 (m, 1H),
1.82−2.04 (m, 5H), 1.46−1.81 (m, 5H); 13C{1H} NMR (100
MHz, CDCl3) δ 150.2 (dd, J = 247.8, 12.7 Hz), 149.0 (dd, J =
246.0, 12.6 Hz), 137.0 (dd, J = 5.3, 4.1 Hz), 129.5, 129.1, 125.0
(dd, J = 6.0, 3.4 Hz), 117.8 (d, J = 16.6 Hz), 117.1 (d, J = 16.8
Hz), 58.6, 40.7, 38.2, 30.9, 30.4, 27.0, 23.2, 22.8; HRMS (ESI)
m/z [M + H]+ calcd for C16H20NF2 264.1558, found 264.1558;
[α]25D = −127.51 (c = 0.5, MeOH); HPLC ChiracelAD-H, 250
mm × 4.6 mm column, 95/5/0.5 hexane/2-propanol/ethanol-
amine, flow rate of 0.5 mL/min, 230 nm UV lamp, 25 °C, t1 =
12.3 min (major), t2 = 12.9 min; 99% ee.
Enantioenriched 1-(3,4-Dichlorobenzyl)-1,2,3,4,5,6,7,8-oc-
tahydroisoquinoline.
8
D
D
[α]20 = −139.80 (c = 0.5, MeOH) [lit. value for (R)-1a: [α]20
=
+139 (c = 1.0, MeOH)]; HPLC Chiracel OJ-H, 250 mm × 4.6 mm
column, 95/5/0.5 hexane/2-propanol/ethanolamine, flow rate of 0.5
mL/min, 230 nm UV lamp, 25 °C, t1 = 9.2 min (major), t2 = 10.2 min;
96% ee.
Protein Crystallization. Protein was crystallized at 18 °C using the
hanging-drop vapor diffusion method. Crystals were obtained by
mixing 1 μL of a protein solution and 1 μL of a reservoir solution
containing 10% PEG 8000 and 100 mM potassium phosphate
monobasic/sodium phosphate dibasic (pH 6.0). The CHAOCCH12‑C2
-
FAD-2a ternary complex was obtained by soaking the protein crystal
into the solution containing 6% PEG 8000, 50 mM potassium
phosphate monobasic/sodium phosphate dibasic (pH 6.0), and 1 mM
1-(4-methoxybenzyl)-HHIQ (2a) for 2 min. Crystals were cryopro-
tected in a reservoir solution supplemented with 20% glycol. X-ray
diffraction data were collected at 100 K on beamline BL18U at the
SSRF (Shanghai Synchrotron Radiation Facility). The data were
processed using HKL3000.43 The structure was determined by
molecular replacement using CHAOIH‑35A (PDB entry 4I59) as the
search model.44 The initial model was automatically built using
PHENIX AutoBuild, followed by manual model building using
COOT45 and structural refinement using PHENIX.refine and
Refmac5.46 Data collection statistics are summarized in Table S5.
The structures of the CHAOCCH12‑C2-FAD binary complex and the
Here, 111 mg of rac-1q was used. Enantioenriched 1q (91 mg,
82% yield) was purified by preparative TLC (15/1 dichloro-
methane/methanol) as a yellow liquid: H NMR (400 MHz,
1
CDCl3) δ 7.34−7.43 (m, 2H), 7.09 (dd, J = 8.2, 2.0 Hz, 1H),
3.30 (d, J = 10.5 Hz, 1H), 2.93−3.09 (m, 2H), 2.76 (ddd, J =
12.1, 7.3, 5.1 Hz, 1H), 2.51 (dd, J = 13.7, 10.5 Hz, 1H), 2.05−
2.19 (m, 1H), 1.82−2.04 (m, 5H), 1.49−1.82 (m, 5H); 13C{1H}
NMR (100 MHz, CDCl3) δ 140.5, 132.3, 131.1, 130.3, 130.2,
129.4, 129.2, 128.7, 58.5, 40.7, 38.2, 30.9, 30.4, 27.0, 23.2, 22.8;
HRMS (ESI) m/z [M + H]+ calcd for C16H20NCl2 296.0967,
D
found 296.0973: [α]25 = −135.70 (c = 0.5, MeOH); HPLC
ChiracelAD-H, 250 mm × 4.6 mm column, 95/5/0.5 hexane/2-
O
J. Org. Chem. XXXX, XXX, XXX−XXX