Jens O. Krause et al.
FULL PAPERS
to a ratio of (NBE-CH2O)3-SiMe:2-propanol:toluene:initiator
of 20:20:45.7:13.9:0.4 (all wt-%). Monolith synthesis was
carried out as described above. Surface-grafting and initiator-
immobilization was accomplished according to the procedure
described above using a solution of exo, exo-7-oxanorborn-2-
ene-5,6-dicarboxylic anhydride (0.32 g, 1.93 mmol) in DMF
(20 wt %), AgNO3 (340 mg, 2.0 mmol) in 2 mL of a 1:5 mixture
of NH3/water and RuCl2( CHPh)(IMesH2)(PCy3) (50 mg,
0.059 mmol) in 2 mL of THF. Ru-loading 0.6 mg/g, corre-
sponding to 7 mg catalyst/g.
RuCl(COO[C6H8O]COOAg)( CHPh)(IMesH2)
(PCy3) (3)
Compound 2 (23.6 mg, 0.059 mmol) was added to a stirred
solution
of
RuCl2( CHPh)(IMesH2)(PCy3)
(50 mg,
0.059 mmol) in 10 mL of dry THF. The solution was stirred
for 20 min at 658C. The color of the solution changed from red
to green, the precipitate was filtered off and the filtrate
evaporated to dryness. It was re-dissolved in a small amount of
benzene and the solid was separated and washed with benzene,
giving the product as
a
green powder; yield: 10 mg
Ä
(0.009 mmol, 15%); FT-IR (ATR): n 2960 (w), 2921 (s),
2847 (w), 1781 (w), 1651 (s), 1585 (w), 1478 (w), 1444 (w), 1411
(s), 1259 (vs), 1173 (w), 1090 (vs), 1016 (vs), 851 (s), 798 (vs)
Synthesis of Monolith-Supported Catalysts Based on
Mono-Carboxylates (6)
1
cmÀ1; H NMR (CDCl3, 258C): d 17.41 (s, 1H, PhCH), 7.87
(d, 2H, CHCCH), 7.06 À 7.22 (m, 7H, aromatics), 4.57 (d, 2H,
CHO), 3.91 (b, 4H, NCH2), 3.80 (m, 2H, CHCO), 2.30 (s, 12H,
NCCCH3), 2.14 (s, 6H, CHCCH3), 1.94 (s, 3H, PCH), 1.80 (s,
12H, PCHCH2), 1.60 (s, 12H, CHCH2CH2), 1.21 (m, 6H,
CHCH2CH2CH2); MALDI-TOF calcd. for C54H73AgClN2O5-
Column dimensions: V 1.26 mL (100 mm  4 mm). The
following amounts were used: NBE (0.5 g mmol), (NBE-
CH2O)3SiMe (0.5 mL, 0.54 mg, 1.28 mmol), 2-propanol
(1.455 mL), toluene (0.391 mL), RuCl2( CHPh)(PCy3)2
(10 mg, 0.012 mmol). This corresponds to
a ratio of
m/z 1104.304; found: 955.476 (MH COOAg); anal. calcd.
20:20:45.7:13.9:0.4 (all wt %). Monolith synthesis was carried
out as described above. Surface-grafting and initiator-immobi-
lization was accomplished according to the procedure describ-
ed above using a solution of 7-oxanorborn-2-ene-5-carboxylic
acid (0.32 g, 2.28 mmol) in DMF (20 wt %), AgNO3 (300 mg,
1.76 mmol) in 2 mL of a 1:5 mixture of NH3/water and
for C54H73AgClN2O5PRu (Mr 1105.549 g/mol): C 58.67, H
6.66, N 2.53; found: C 58.53, H 6.28, N 3.78.
Synthesis of Monolith-Supported Catalysts Based on
Dicarboxylates
RuCl2( CHPh)(IMesH2)(PCy3) (50 mg, 0.059 mmol) in 2 mL
of THF. Ru-loading 0.8 mg/g, corresponding to 9 mg catalyst/g.
A. Using DMN-H6 as Cross-linker (4): Column dimensions:
V 1.57 mL (125 Â 4 mm i. d.). The following amounts
were used: norborn-2-ene (NBE, 1.00 g, 10.6 mmol), DMN-
H6 (0.96 mL, 1 1.038 g/mL, 6.3 mmol), 2-propanol 2.94 mL,
Synthesis of Silica-Supported Catalysts 7 and 8 Based
on Dicarboxylates
toluene 0.63 mL, RuCl2( CHPh)(PCy3)2 (20 mg, 0.024 mmol),
PPh3 (0.07 mL of a solution containing 30 mg PPh3/10 mL of
toluene). This corresponds to a ratio of NBE:DMN-H6:2-
propanol:toluene:initiator:PPh3 of 20:20:46.2:13.4:0.4 (all
Preparation of Norborn-2-ene Derivatized Nucleosil 300 7
(NBE-Nucleosil 300 7): Nucleosil 300 7 was suspended in
200 mL of toluene and refluxed in a Dean-Stark apparatus for
24 h until all water was removed. The silica was filtered off,
dried under vacuum and re-suspended in 150 mL of dry
CH2Cl2. Dry triethylamine (3.36 mL 2.44 g, 24.63 mmol) and
wt %). Asolution of 2-propanol, NBE and DMN-H was
6
stirred for 30 minutes and added to a stirred solution of toluene,
the initiator and the PPh3 solution, chilled to À 308C. Stirring
was continued for 2 min after which the column (chilled to
08C) was filled with the reaction mixture. After polymerization
for 30 minutes at 08C and another 30 minutes at room
temperature the column was washed with dry THF. Asolution
of exo, exo-7-oxanorborn-2-ene-5,6-dicarboxylic anhydride
(0.2 g, 1.2 mmol) in dry DMF (20 wt %) was added and graft-
polymerization was carried out at 458C over 12 h. The column
was washed with a 40 vol. % solution of EVE in THF, followed
by pure THF. Asolution of AgNO 3 (340 mg, 2.0 mmol) in 2 mL
of a 1:5 mixture of NH3 and water was prepared and passed
through the column maintaining a temperature of 458C. The
support was consecutively washed with water until a base- and
silver-free effluent was assured, then with dry THF.
(norborn-2-ene-5-yl)trichlorosilane
(0.79 mL,
1.02 g,
4.5 mmol) were added to the stirred suspension. After reflux-
ing for 6 h, trimethylchlorosilane (0.68 mL, 0.58 g, 5.38 mmol)
and dimethyldichlorosilane (0.34 mL, 0.36 g, 2.78 mmol) were
added and the suspension was refluxed for another 2 h. 25 mL
of dry MeOH were added and the mixture was stirred for
15 min, then the suspension was filtered off, washed with dry
MeOH, dry CH2Cl2, dry Et2O and dried under vacuum.
Elemental anal. found: C 2.98, H 0.47, N 0.00.
Determination of Norborn-2-ene Loading: Br2 (65 mL,
1.26 mmol) was added to 500 mL of MeOH and the solution
was saturated with NaBr. Titration of the solution with a
solution of 2.5 mmol/L Na2S2O3 revealed a concentration of
2.97 x 10À6 mol Br2/mL. Three samples (180 mg each) of the
derivatized Nucleosil were suspended in MeOH and 10 mL of
the Br2 solution and 1 mL of a saturated NaI solution in water
were added. Afew drops of a freshly prepared aqueous starch
solution were added and stirring was continued for 20 min.
Then the suspension was titrated with a 2.5 mmol/L Na2S2O3
solution revealing a loading of 7.7 Â 10À5 mol norborn-2-ene/g
Nucleosil.
RuCl2( CHPh)(IMesH2)(PCy3) (50 mg, 0.059 mmol) dis-
solved in 2 mL of dry THF was added and reaction was
allowed to proceed at 658C over 20 min. Finally, the monolith
was washed with dry THF until the washings were colorless.
Ru-loading 0.9 mg/g, corresponding to 10 mg catalyst/g.
B. Using (NBE-CH2-O)3-SiMe as a Cross-linker (5): Col-
umn dimensions: V 1.57 mL (125 Â 4 mm i. d.). The follow-
ing amounts were used: NBE (0.5 g), (NBE-CH2O)3SiMe
(0.5 mL), 2-propanol (1.46 mL), toluene (0.39 mL),
Grafting of NBE-Nucleosil 300 7: NBE-Nucleosil 300
(3.37 g) was suspended in 50 mL dry DMF, RuCl2( CHPh)-
7
RuCl2( CHPh)(PCy3)2 (10 mg, 0.012 mmol). This corresponds
1002
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Adv. Synth. Catal. 2003, 345, 996 1004