2026
L. Zhang, K.S. Chan / Journal of Organometallic Chemistry 692 (2007) 2021–2027
(Merck, activity I, 70–230 mesh) was used for column
chromatography.
4.4. Sealed tube experiments
1H NMR spectra were recorded on a Bruker DPX 300
Triphenylphosphine solution (0.01 mL, 0.001 mmol,
0.1 M in C6D6, 1 equiv.) was added to the solution of
[Rh(tmp)] (2) in the NMR tube at r.t. Degassed ester 3a
solution (10 equiv.) in C6D6 was added to the adduct solu-
tion, then the NMR tube was sealed under vacuum. The
mixture was heated at 130 ꢁC for 30 h under N2 in the
absence of light. The reaction was monitored with 1H
NMR spectroscopy.
¨
(300 MHz) spectrometer. Spectra were referenced inter-
nally to the residual proton resonance in CDCl3 (d
7.26 ppm), tetramethylsilane (TMS, d 0.00 ppm) or with
C6D6 (d 7.15 ppm) as the internal standard. Chemical shifts
(d) were reported as part per million (ppm) in d scale down-
field from TMS or (Me3Si)4Si.
4.1. Preparation of 5,10,15,20-
tetramesitylporphyrinatorhodium(II) [Rh(tmp)] (2) [34]
4.5. Reaction of [Rh(tmp)] (2) and amides 5a–5l with PPh3
added
To a Teflon screwheaded stoppered flask, Rh(tmp)CH3
(1) (10.0 mg, 0.011 mmol) was charged and dissolved in
C6H6 (4.0 mL) to obtain a clear orange solution. The reac-
tion mixture was then degassed by the freeze–pump–thaw
method (three cycles) and refilled with N2. The reaction mix-
ture was irradiated under a 400 W Hg-lamp at 6–10 ꢁC until
all the starting material was consumed as indicated by TLC
analysis (ꢀ8 h) to give Rh(tmp) (2) in 80% yield.
Triphenylphosphine solution (0.1 mL, 0.01 mmol, 0.1 M
in C6H6, 1 equiv.) was added to the solution of [Rh(tmp)]
(2) at r.t. Degassed amide solution (5 equiv.) in benzene
was added to the adduct solution, and the mixture was
heated under N2 in the absence of light. The crude product
was purified by chromatography on silica gel to give the
product.
4.2. Reaction of [Rh(tmp)] (2) and esters 3a–3j with PPh3
added
4.6. Preparation of (5,10,15,20-
tetramesitylporphyrinato)(N-phthalimido)methyl-
rhodium(III) [Rh(tmp)CH2N-Pht] (6) [34]
Triphenylphosphine solution (0.1 mL, 0.01 mmol, 0.1 M
in C6H6, 1 equiv.) was added to the solution of [Rh(tmp)] (2)
at r.t. Degassed ester solution (5 equiv.) in benzene was
added to the adduct solution, and the mixture was heated
under N2 in the absence of light. The crude product was
purified by chromatography on silica gel to give the product.
To a solution of Rh(tmp)I (50 mg, 0.049 mmol) in EtOH
(30 mL), a solution of NaBH4 (9.5 mg, 0.25 mmol) in aqu-
ous NaOH (0.1 M, 2 mL) was added under N2. The solu-
tion mixture was heated at 50–60 ꢁC under N2 for 1 h
and then cooled to r.t. N-(bromomethyl)phthalimide
(157 mg, 0.49 mmol) was added under N2. The mixture
was stirred at r.t. for 15 min. A reddish orange suspension
was formed. The reaction was worked up by addition of
CH2Cl2 and H2O. the crude product was extracted with
CH2Cl2 (200 mL), washed with H2O (25 mL · 3), dried
over anhydrous MgSO4, filtered and rotary evaporated
off to dryness. After purification by column chromatogra-
phy on silica gel using hexane:CH2Cl2 (5:1) to hex-
ane:CH2Cl2 (2:1) as the gradient eluent, a red solid of 6
was obtained (42.0 mg, 0.040 mmol, 82%). Rf = 0.51 (hex-
4.3. Preparation of (5,10,15,20-
tetramesitylporphyrinato)rhodium(III) ethyl
[Rh(tmp)CH2CH3] (4) [34]
Red suspension of Rh(tmp)I (200 mg, 0.15 mmol) in
EtOH (100 mL) and the solution of NaBH4 (28 mg,
0.74 mmol) in 0.5 M NaOH (8 mL) wre purged with N2
separately for about 15 min. The NaBH4 solution was
added to the suspension of Rh(tmp)I via cannular. The
reaction mixture was heated at 55 ꢁC for 1 h under N2.
After cooled to r.t., EtI was added via syringe. A bright
red suspension formed immediately and it was stirred over-
night at room temperature. The reaction was worked up by
addition of CH2Cl2 and H2O. The crude product was
extracted with CH2Cl2 (200 mL), washed with H2O
(25 mL · 3), dried over anhydrous MgSO4, filtered and
rotary evaporated off to dryness. After purification by col-
umn chromatography on silica gel using hexane:CH2Cl2
(10:1) to hexane:CH2Cl2 (5:1) as the gradient eluent, bright
red solid (4) (113 mg, 0.12 mmol, 83%) was obtained which
was further purified by recrystallization from CH2Cl2/hex-
ane. Rf = 0.67 (hexane:CH2Cl2 = 5:1); 1H NMR
1
ane:CH2Cl2 = 1:1). H NMR (300 MHz, C6D6) d ꢂ2.19
(d, 2H, JRh–CH ¼ 3:6 Hz), 1.88 (s, 12H), 2.25 (s, 12H),
2
2.45 (s, 12H), 6.42 (d, 2H, J = 8.4 Hz), 6.55 (dd, 2H,
J = 3.0 Hz, J = 5.4 Hz), 6.90 (s, 2H), 7.22 (s, 4H), 7.42 (s,
2H), 8.80 (s, 8H). 13C NMR (CDCl3, 100 MHz) 21.98,
22.12, 22.66, 120.61, 122.54, 128.41, 131.42, 131.56,
133.37, 138.08, 139.15, 139.48, 140.19, 143.64, 163.43.
Anal. Calc. for C65H58N5O2Rh: C, 74.77; H, 5.60; N,
6.70. Found: C, 74.40; H, 5.99; N, 6.43%. HRMS (FAB):
Calc. for (C65H58N5O2Rh)+: m/z 1043.3640. Found: m/z
1043.36097.
4.7. Sealed tube experiments
(300 MHz, CDCl3)
d
ꢂ4.74 (dq, 2H, J = 7.5 Hz,
JRh–CH ¼ 3:6 Hz), ꢂ4.22 (t, 3H, J = 5.7 Hz), 1.93 (s,
Triphenylphosphine solution (0.01 mL, 0.001 mmol,
0.1 M in C6D6, 1 equiv.) was added to the solution of
2
12H), 1.90 (s, 12H), 2.61 (s, 12H), 7.25 (s, 4H), 8.45 (s, 8H).