organic compounds
(m, 14H), 6.84 (m, 5H), 6.63 (m, 2H), 6.36 (s, 1H), 4.57 (s, 1H), 4.38 (d,
J = 13.63 Hz, 1H), 4.24 (dd, J = 3.38 and 12.13 Hz, 1H), 4.00 (s, 3H),
3.73 (s, 3H), 3.39 (dd, J = 4.32 and 12.58 Hz, 1H), 3.31 (d, J = 13.85 Hz,
1H), 2.29 (dd, J = 3.38 and 16.88 Hz, 1H), 0.0 (s, 9H).
change could be that the benzyl group on the N atom forces
the phenyl rings at the C10 atom to be the furthest away from
it, hence adopting the sc-endo conformation.
Proline diaryl alcohols have been used as successful chiral
catalysts by exploiting the same rotation along the C9—C10
bond (Diner et al., 2008). This change, which is brought about
by different groups on the methanol O atom, makes the
current study particularly useful. This feature is found in (I)
which, when tested for its catalytic activity in the Diels–Alder
reaction, showed poor yields. The structural data demon-
strated how we could improve the catalytic reactivity by
reducing the steric bulk of the ligand. A successful catalyst was
obtained by removing the phenyl moieties from (I) (Naicker,
Petzold et al., 2010).
Compound (I)
Crystal data
3
˚
C31H31NO3
V = 1226.7 (3) A
Z = 2
Mr = 465.57
Monoclinic, P21
a = 11.4071 (14) A
b = 6.4750 (8) A
c = 16.961 (2) A
ꢄ = 101.707 (2)ꢂ
Mo Kꢁ radiation
ꢅ = 0.08 mmꢁ1
T = 173 K
0.22 ꢄ 0.14 ꢄ 0.09 mm
˚
˚
˚
Data collection
Experimental
Bruker APEXII DUO
diffractometer
Absorption correction: multi-scan
(SADABS; Sheldrick, 2008)
Tmin = 0.645, Tmax = 0.746
11498 measured reflections
3737 independent reflections
3191 reflections with I > 2ꢆ(I)
Rint = 0.051
To (1R,3S)-2-benzyl-3-(1,1-diphenylethyl)-6,7-dimethoxy-1-phenyl-
1,2,3,4-tetrahydroisoquinoline (0.4 g, 0.72 mmol), derived from
l-DOPA (Naicker, Petzold et al., 2010), in MeOH–THF (1:1 v/v,
20 ml) was added half an equivalent by mass of 10% palladium on
carbon Pd/C under hydrogen (approximately 1 atm). The reaction
was stirred for 2 h. The crude product was obtained by filtering the
Pd/C through a plug of Celite and the filtrate was then concentrated
to dryness. The resulting residue was purified by column chromato-
graphy (50:50 EtOAc–hexane, RF = 0.6) to yield (I) as a white solid
[yield 0.2 g, 60%; m.p. 463–465 K; [ꢁ]2D0 ꢁ10.0 (c 0.11 in CHCl3)].
Recrystallization from ethyl acetate afforded colourless crystals
suitable for X-ray analysis. IR (neat, ꢂmax, cmꢁ1): 2934, 1514, 1448,
Refinement
R[F2 > 2ꢆ(F2)] = 0.043
wR(F2) = 0.108
S = 1.05
3737 reflections
320 parameters
2 restraints
H atoms treated by a mixture of
independent and constrained
refinement
ꢁ3
˚
Áꢇmax = 0.23 e A
ꢁ3
˚
Áꢇmin = ꢁ0.23 e A
1
1244, 1224, 1063, 698; H NMR (400 MHz, CDCl3, ꢃ, p.p.m.): 7.47–
7.12 (m, 12H), 7.08 (t, J = 7.6 Hz, 2H), 6.92 (d, J = 7.6 Hz, 2H), 6.65 (s,
1H), 6.40 (s, 1H), 5.23 (s, 1H), 3.95 (dd, J = 11.5 and 3.6 Hz, 1H), 3.86
(s, 3H), 3.70 (s, 3H), 2.92–2.75 (m, 4H), 2.52 (dd, J = 16.2 and 11.5 Hz,
3H).
Compound (II)
Crystal data
3
˚
V = 3350 (5) A
Z = 4
C40H43NO3Si
Mr = 613.84
Monoclinic, P21
a = 11.045 (10) A
b = 17.008 (15) A
To a stirred solution of [(1R,3S)-3-(hydroxydiphenylmethyl)-6,7-
dimethoxy-1-phenyl-1,2,3,4-tetrahydroisoquinolin-2-yl](phenyl)-
methanone (0.6 g, 1.1 mmol), derived from l-DOPA (Naicker,
Petzold et al., 2010), in dry dichloromethane (20 ml) and triethyl-
amine (0.18 ml, 1.3 mmol), trimethylsilyl trifluoromethanesulfonate
(0.24 ml, 1.33 mmol) was added dropwise at 273 K under an inert
atmosphere. The mixture was allowed to warm to room temperature
and was stirred overnight. The mixture was washed with water, the
organic extracts were combined and dried over anhydrous Na2SO4,
and the solvent was removed in vacuo. The resulting residue was
Mo Kꢁ radiation
ꢅ = 0.11 mmꢁ1
T = 100 K
0.22 ꢄ 0.12 ꢄ 0.10 mm
˚
˚
˚
c = 18.489 (15) A
ꢄ = 105.287 (15)ꢂ
Data collection
Bruker APEXII DUO
diffractometer
Absorption correction: multi-scan
(SADABS; Sheldrick, 2008)
Tmin = 0.976, Tmax = 0.989
37993 measured reflections
17263 independent reflections
11255 reflections with I > 2ꢆ(I)
Rint = 0.064
purified by column chromatography (20:80 EtOAc–hexane, RF
=
0.55) to afford (II) as a white solid [yield 0.5 g, 75%; m.p. 458–460 K;
[ꢁ]2D057.58 (c 0.33 in CHCl3)]. Recrystallization from acetone afforded
colourless crystals suitable for X-ray analysis. IR (neat, ꢂmax, cmꢁ1):
2956, 1513, 1245, 839, 696; 1H NMR (400 MHz, CDCl3, ꢃ, p.p.m.): 7.17
Refinement
R[F2 > 2ꢆ(F2)] = 0.057
wR(F2) = 0.124
S = 0.99
17263 reflections
812 parameters
1 restraint
H-atom parameteꢁrs3 constrained
˚
Áꢇmax = 0.38 e A
ꢁ3
˚
Áꢇmin = ꢁ0.41 e A
Absolute structure: Flack (1983)
Flack parameter: 0.00 (10), 8119
Friedel pairs
Table 1
Hydrogen-bond geometry (A, ) for (I).
ꢂ
˚
Cg is the centroid of the C18–C23 ring.
D—Hꢀ ꢀ ꢀA
D—H
Hꢀ ꢀ ꢀA
Dꢀ ꢀ ꢀA
D—Hꢀ ꢀ ꢀA
Atom H1N on N1 of (I) was located in a difference electron-
density map and refined isotropically with a simple bond-length
˚
restraint of N1—H1N = 0.96 (1) A. All remaining H atoms were
positioned geometrically, with C—H = 0.95 (aromatic), 0.98 (methyl),
C11—H11Aꢀ ꢀ ꢀCgi
C30—H30Aꢀ ꢀ ꢀO1ii
C30—H30Aꢀ ꢀ ꢀO2ii
0.98
0.98
0.98
2.57
2.54
2.59
3.45 (2)
3.356 (2)
3.400 (2)
150
140
140
˚
0.99 (methylene) or 1.00 A (methine), and refined as riding on their
1
2
Symmetry codes: (i) x; y þ 1; z; (ii) ꢁx; y ꢁ ; ꢁz þ 1.
ꢃ
o102 Naicker et al. C31H31NO3 and C40H43NO3Si
Acta Cryst. (2011). C67, o100–o103