Article
Inorganic Chemistry, Vol. 50, No. 1, 2011 281
possible use of cis-6 would be the synthesis of its Rh-105
radioisotope, a beta emitter, as a potential radiopharmaceu-
tical. We feel that these representative bioorganometallic
complexes, such as cis-6 and trans-7, and their Cp*Ru
analogues, could be used for these specific purposes, and
hopefully will generate new directions for the bioorganome-
tallic chemistry discipline.
for C27H31NO2,1/4 H2O: C, 79.89 ; H, 7.81 ; N, 3.45. Found: C,
79.72 ; H, 7.73 ; N, 3.27.
Trans-2 Data: 1H NMR (DMSO-d6, 400 MHz) 0.84 (t, J=7.4
Hz, 3H, H-4), 1.84 (quint, J = 6.8 Hz, 2H, H-24), 2.14 (s, 6H,
N(CH3)2), 2.35 (t, J=7.1 Hz, 2H, H-25), 2.39 (q, J=7.3 Hz, 2H,
H-3), 3.99 (t, J = 6.4 Hz, 2H, H-23), 6.39 (d, J = 8.6 Hz, 2H,
H-19, H-21), 6.59 (d, J=8.6 Hz, 2H, H-18, H-22), 6.90 (d, J=
8.7 Hz, 2H, H-13, H-15), 7.06-7.11 (m, 5H, H-6, H-8, H-10,
H-12, H-16), 7.15-7.19 (m, 2H, H-7, H-9). 13C NMR (DMSO-
d6, 100 MHz) 13.6 (C-4), 27.2 (C-24), 28.7 (C-3), 45.4 (N(CH3)2),
55.9 (C-25), 65.8 (C-23), 114.2 (C-13, C-15), 114.5 (C-19, C-21),
126.1 (C-8), 128.0 (C-7, C-9), 129.6 (C-6, C-10), 130.3 (C-12,
C-16), 131.6 (C-18, C-22), 133.8 (C-17), 135.8 (C-11), 138.1 (C-
1), 139.9 (C-2), 142.4 (C-5), 155.4 (C-20) 157.5 (C-14). White
crystals, mp 183 °C. Anal. Calc. for C27H31NO2,1/4 H2O: C,
79.89 ; H, 7.81 ; N, 3.45. Found: C, 79.54; H, 7.81; N, 3.43.
Reaction of cis-1, with in Situ Formed [Cp*Rh(CH3OH)3]-
(OTf)2 in CH3OH: cis-4(CH3OH). In a Schlenk tube, 10 mg
(0.025 mmol) of cis-1 and 14 mg of [Cp*Rh(H2O)3](OTf)2 (0.025
mmol) were dissolved in 2 mL of dry CH3OH to form [Cp*Rh-
(CH3OH)3](OTf)2, in situ, under Argon. The solution was stirred at
RT for 15 min. A clear orange solution obtained was concentrated
under vacuum to about 0.5 mL. Then, 10 mL of dry diethyl ether
was added into the solution to precipitate cis-4(CH3OH) as an
orange oil. The mixture was left in a refrigerator for 1 h. The
solution was stripped off, and the orange oil was washed with
2 mL of diethyl ether and dried under vacuum. Complex cis-
4(CH3OH) was isolated as an orange solid, 20 mg, 85% yield. 1H
NMR (CD2Cl2, 400 MHz) 1.00 (t, J=7.4 Hz, 3H, H-4), 1.01 (s,
15H, (C5(CH3)5), 2.15-2.20 (m, 2H, H-24), 2.55 (q, J=7.4 Hz,
2H, H-3), 2.90 (d, JH-Rh=5.0 Hz, 6H, N(CH3)2), 3.24-3.45 (m,
2H, H-25), 3.98 (t, J=5.6 Hz, 2H, H-23), 6.60 (d, J=8.8 Hz, 2H,
H-19, H-21), 6.83 (d, J=8.8 Hz, 2H, H-18, H-22), 7.10-7.22 (m,
5H, H-6, H-7,H-8, H-9, H-10), 7.26 (d, J = 8.5 Hz, 2H, H-12,
H-16), 7.44 (d, J=8.5 Hz, 2H, H-13, H-15). 13C NMR (CD2Cl2,
100 MHz) 7.4 (C5(CH3)5), 13.2 (C-4), 24.3 (C-24), 29.1 (C-3),
43.4 (N(CH3)2), 56.0 (C-25), 64.0 (C-23), 90.2 (C5(CH3)5), 113.0
(C-19, C-21), 121.8 (C-13, C-15), 127.6 (C-8), 127.7 (C-7, C-9),
129.5 (C-6, C-10), 130.3 (C-12, C-16), 131.7 (C-18, C-22), 136.2
(C-17), 137.7 (C-1, C-11), 140.9 (C-2), 142.3 (C-5), 156.0 (C-20),
163.1 (C-14). ESI-MS (ES): m/z: 639 [Mþ - 2CF3SO3-].
Reaction of trans-2 with in Situ Formed [Cp*Rh(CH3OH)3]-
(OTf)2 in CH3OH: trans-5(CH3OH). In a Schlenk tube, 10 mg
(0.025 mmol) of trans-2, and 14 mg of [Cp*Rh(H2O)3](OTf)2
(0.025 mmol) were dissolved in 2 mL of dry CH3OH to form
[Cp*Rh(CH3OH)3](OTf)2, under Argon. The solution was stirred
at RT for 15 min and then the clear orange solution obtained
was concentrated under vacuum to about 0.5 mL. Then, 10 mL
of dry diethyl ether was added into the solution, to precipitate
the complex as an orange oil. The mixture was left in a refrig-
erator for 1 h. The solution was stripped off, and the orange oil
was washed with 2 mL of diethyl ether, and then dried under
vacuum. The trans-η1-N-complex, 5(CH3OH), was isolated as
an orange solid, 22 mg, 91% yield. 1H NMR (CD2Cl2, 400
MHz) 0.70 (s, 15H, (C5(CH3)5), 0.98 (t, J = 7.3 Hz, 3H, H-4),
2.25-2.29 (m, 2H, H-24), 2.53 (q, J=7.3 Hz, 2H, H-3), 2.96 (d,
Experimental Section
All purchased starting materials and solvents were checked
for purity. The NMR data were recorded at RT on a Bruker
Avance 400 spectrometer operating at 400.1 and 100.6 MHz
for 1H and 13C, respectively, and using a BBiz probe. The 1H
and 13C chemicals shifts (TMS) were referenced to the re-
sidual solvent peaks. For all the compounds, assignments of
individual resonances were achieved using a combination of
one-dimensional (1D) and two-dimensional (2D) homo and
hetero experiments; that is, COSY, HMQC, and HMBC.
HMBC permits distinguishing the PhOH and PhOR aromatic
groups for each compound, because of the long distance
correlation between the protons, H-23 (the PhO(CH2)3NMe2
aromatic ring), and the quaternary aromatic carbons C-14 or
C-20, for respectively, the cis-6 or trans-7 isomer, and similar
HMBC and NOESY experiments that defined cis-1, trans-2,
cis-4, trans-5, and 9. This experiment also permitted assign-
ments of all the other quaternary carbons. Finally, the NOESY
experiment provided the unequivocal assignment of the cis-6
or trans-7 configurations for the η6-Cp*Rh phenol ring bind-
ing site.
[Cp*Rh(solvent)3](OTf)2:1HNMRChemicalShifts(ppm)
for Solvents, D2O, CD3OD, DMSO-d6, and H2O in CD2Cl2:
1H NMR (300 MHz): Cp*, 1.70 (CD2Cl2) ;1.58 (D2O) ; 1.69
(CD3OD); 1.53 (DMSO).
Synthesis of cis-1 and trans-25. In a Schlenk tube, 1,1-di-
hydroxyphenyl-2-phenyl-but-1-ene (3.16 g, 10 mmol) was dis-
solved in anhydrous dimethylformamide (DMF, 30 mL). NaH
(60% in oil, 1.51 g, 15 mmol) was then added as a powder into
the solution, within 10 min. The solution was progressively
heated to 100 °C (20 min). In another Schlenk tube, Et3N (1.51 g,
15 mmol) was added to a suspension of Cl(CH2)3NMe2.HCl
(2.37 g, 15 mmol) in 30 mL of tetrahydrofuran (THF). After
stirring for 1 h, the solution was filtrated and concentrated to
3 mL, and then 2 mL of DMF was added. This chloroamine
solution was slowly added to the first solution maintained at 100 °C
(10 min). After 1 h of heating, the mixture was allowed to cool
to RT, and then 200 mL of ethyl acetate was added. The solution
was washed with 2 ꢀ m_x00d7;50 mL of H2O. After removal of
the solvent, the crude product was first purified by silica gel flash
column chromatography using acetone:Et3N, 10:1 as eluent.
Then 2.10 g mixture (1:1) of cis-1 and trans-2, were isolated as an
oil (52.5%), with 1.08 g of 1,1-dihydroxyphenyl-2-phenyl-but-1-
ene being recovered (34%). Cis-1 and trans-2 were separated by
semipreparative HPLC, using CH3CN (with 1% Et3N):H2O,
80:20 as eluent. Isomers cis-1 and trans-2 were identified by
COSY, NOESY, HMQC, and HMBC NMR correlation ex-
periments. Cis-1 Data: 1H NMR (DMSO-d6, 400 MHz): 0.84 (t,
J=7.3 Hz, 3H, H-4), 1.74 (quint, J=6.7 Hz, 2H, H-24), 2.09 (s,
6H, N(CH3)2), 2.26 (t, J=7.1 Hz, 2H, H-25), 2.40 (q, J=7.3 Hz,
2H, H-3), 3.82 (t, J = 6.4 Hz, 2H, H-23), 6.55 (d, J = 8.7 Hz,
2H, H-19, H-21), 6.69 (d, J=8.7 Hz, 2H, H-18, H-22), 6.74 (d,
J = 8.4 Hz, 2H, H-13, H-15), 6.97 (d, J = 8.4 Hz, 2H, H-12,
H-16), 7.06-7.11 (m, 3H, H-8, H-6, H-10), 7.14-7.19 (m, 2H,
H-7,H-9). 13C NMR (DMSO-d6, 100 MHz) 13.6 (C-4), 27.1
(C-24), 28.7 (C-3), 45.4 (N(CH3)2), 55.8 (C-25), 65.6 (C-23),
113.4 (C-19, C-21), 115.1 (C-13, C-15), 126.1 (C-8), 128.1 (C-7,
C-9), 129.6 (C-6, C-10), 130.3 (C-12, C-16), 131.6 (C-18, C-22),
134.1 (C-11), 135.5 (C-17), 138.1 (C-1), 140.1 (C-2), 142.4 (C-5),
156.3 (C-14) 156.7 (C-20). White crystals, mp 157 °C. Anal. Calc.
JH-Rh =5.0 Hz, 6H, N(CH3)2), 3.33-3.38 (m, 2H, H-25), 4.12
(t, J=5.5 Hz, 2H, H-23), 6.79 (d, J=8.6 Hz, 2H, H-18, H-22),
6.91 (d, J = 8.8 Hz, 2H, H-13, H-15), 6.93 (d, J = 8.6 Hz, 2H,
H-19, H-21), 7.07-7.10 (m, 1H, H-8), 7.12-7.18 (m, 6H, H-6,
H-7, H-9, H-10, H-12, H-16). 13C NMR (CD2Cl2, 100 MHz) 7.1
(C5(CH3)5), 13.0 (C-4), 24.3 (C-24), 28.5 (C-3), 43.3 (N(CH3)2),
55.9 (C-25), 64.2 (C-23), 89.7 (C5(CH3)5), 113.6 (C-13, C-15),
120.9 (C-19, C-21), 125.5 (C-8), 127.4 (C-7, C-9), 129.5 (C-6,
C-10), 130.2 (C-12, C-16), 131.5 (C-18, C-22), 136.4 (C-11),
137.4 (C-17), 137.8 (C-1), 140.9 (C-2), 142.8 (C-5), 156.8 (C-14),
163.8 (C-20). ESI-MS: m/z: 639 [Mþ - 2CF3SO3-].
Reaction of cis-1, with [Cp*Rh(H2O)3](OTf)2 in CH2Cl2:
η6-Complex, cis-6. In a Schlenk tube, 40 mg (0.10 mmol) of cis-1