References and Notes
For selected reviews on olefin metathesis,
see:
1a
Trnka
TM.
Grubbs RH.
Acc.
Chem. Res.
2001,
34:
18
1b
Handbook of Metathesis
Grubbs RH.
Wiley-VCH;
Weinheim:
2003.
1c
Connon SJ.
Blechert S.
Angew.
Chem. Int. Ed.
2003,
42:
1900
1d
Astruc D.
New J.
Chem.
2005,
29:
42
1e
Nicolaou KC.
Bulger PG.
Sarlah D.
Angew. Chem. Int. Ed.
2005,
44:
4490
1f
Boeda F.
Clavier H.
Nolan SP.
Chem.
Commun.
2008,
2726
1g For an industrial perspective: Thayer AM.
Chem. Eng. News
2007,
85:
37
2 Review: Clavier H.
Grela K.
Kirschning A.
Mauduit M.
Nolan SP.
Angew.
Chem. Int. Ed.
2007,
46:
6786
3
Hong SH.
Day MW.
Grubbs RH.
J.
Am. Chem. Soc.
2004,
126:
7414
4 Review: SledŸ P.
Mauduit M.
Grela K.
Chem.
Soc. Rev.
2008, in press; DOI: 10.1039/b711482f
5a
Grela K.
Harutyunyan S.
Michrowska A.
Angew. Chem. Int. Ed.
2002,
41:
4038
5b
Michrowska A.
Bujok R.
Harutyunyan S.
Sashuk V.
Dolgonos G.
Grela K.
J. Am. Chem. Soc.
2004,
126:
9318
For a short overview on EWG-activated Hoveyda catalysts,
see:
5c
Grela K.
Michrowska A.
Bieniek M.
Chem.
Rec.
2006,
6:
144
5d
Michrowska A.
Grela K.
Pure Appl. Chem.
2008,
80:
31
6a
Guajski Ł.
Michrowska A.
Bujok R.
Grela K.
J.
Mol. Catal. A: Chem.
2006,
348:
118
6b
Michrowska A.
Guajski Ł.
Kaczmarska Z.
Mennecke K.
Kirschning A.
Grela K.
Green Chem.
2006,
8:
685
6c
Michrowska A.
Mennecke K.
Kunz U.
Kirschning A.
Grela K.
J.
Am. Chem. Soc.
2006,
128:
13261
7a
Guajski Ł.
Michrowska A.
Narożnik J.
Kaczmarska Z.
Rupnicki L.
Grela K.
ChemSusChem
2008,
1:
103
7b For a review on aqueous
olefin metathesis, see: Burtscher D.
Grela K.
Angew. Chem. Int. Ed.
2008, in press;
DOI: 10.1002/anie.200801451h
8
Bieniek M.
Michrowska A.
Guajski Ł.
Grela K.
Organometallics
2007,
26:
1096
9
Synthesis of Complex
7
Carbene complex 2b (94.9
mg, 0.10 mmol), CuCl (14.9 mg, 0.15 mmol), and toluene (4 mL) were
placed in a Schlenk flask equipped with a condenser. A solution
of styrene (27.2 mg, 0.12 mmol) in toluene (2 mL) was added and
the resulting solution was stirred under argon at 80 ˚C
for 1 h. The reaction mixture was concentrated in vacuum and the resulting
material was purified by column chromatography on SiO2.
Elution with c-hexane-EtOAc-Et3N
(4:1:0.1, v/v/v) yielded 7 as
a dark brown microcrystalline solid (49.6 mg, 71%) after
removal of the solvent, washing with a minimal amount of cold n-pentane and drying under vacuum. ¹H NMR
(500 MHz, CDCl3): δ = 1.14 (t, J = 7.1 Hz,
6 H), 1.42 (d, J = 6.1
Hz, 6 H), 2.38 (s, 6 H), 2.49 (s, 12 H), 3.31 (t, J = 7.1
Hz, 4 H), 4.15 (s, 4 H), 4.86 (hept, J = 6.1
Hz, 1 H), 6.00 (d, J = 1.6
Hz, 1 H), 6.12 (dd, J = 8.8,
2.2 Hz, 1 H), 6.68 (d, J = 8.8
Hz, 1 H), 7.04 (s, 4 H), 15.65 (s, 1 H) ppm. ¹³C NMR
(125 MHz, CDCl3): δ = 12.8, 20.0, 21.5,
25.8, 45.5, 55.0, 74.4, 96.3, 104.3, 115.0, 125.6, 129.7,130.5,
138.3, 138.3, 138.8, 150.8, 155.8, 216.2, 298.0 ppm.
Synthesis of Complex 10
Carbene
complex 7 (27.9 mg, 0.04 mmol) was placed
in a flask and dissolved in CH2Cl2 (2 mL).
Next, PTSA˙H2O was added, and this mixture was
stirred for 30 min. During that time the reaction mixture changed
its colour from brown to green. The reaction mixture was concentrated
in vacuum and precipitated from CH2Cl2-n-pentane and dried under vacuum to afford
the title compound 10 (34.8 mg, 99%)
as a green microcrystalline solid. ¹H NMR (500
Hz, CDCl3): δ = 1.16 (t, J = 6.7 Hz,
6 H), 1.21 (d, J = 6.1
Hz, 6 H), 2.34 (s, 3 H), 2.39 (s, 6 H), 2.45 (s, 12 H), 3.28 (s,
3 H), 3.71 (s, 3 H), 4.18 (s, 4 H), 4.90 (hept, J = 6.1
Hz, 1 H), 6.92 (d, J = 8.5 Hz,
1 H), 7.06 (s, 4 H), 7.07 (dd, J = 4.9
Hz, 1 H), 7.16 (d, J = 7.9
Hz, 1 H), 7.29 (d, J = 15.8
Hz, 1 H), 7.75 (d, J = 7.9 Hz,
1 H) ppm. ¹³C NMR (500 MHz, CDCl3): δ = 10.4,
21.2, 21.5, 21.8, 29.8, 51.0, 53.9, 77.5, 109.7, 115.2, 123.4, 126.0, 129.0,
129.2, 129.5, 136.1, 139.2, 140.7, 141.2, 145.6, 152.9, 208, 291
ppm. ESI-HRMS: m/z calcd for C42H54N3O4C¹0²Ru [M - 2
Cl - H+]: 798.2879; found: 798.2896.
10 Complex 2b has
been previously used for preparing of Hoveyda catalyst 3b, albeit with moderate 40% yield,
see: Randl S.
Gessler S.
Wakamatsu H.
Blechert S.
Synlett
2001,
430
11
Oelze B.
Albert D.
Kirschning A.
Org.
Biomol. Chem.
2008,
6:
2412
12 We observed that after filtration
of the reaction mixture the material deposited on SiO2 is
still green which is a clear indication that active catalyst has
been removed. The catalyst decomposition products are commonly brown-black.
13
General Procedure
for Metathesis Reactions
A reaction tube equipped
with a magnetic stirring bar was charged with CH2Cl2 (10
mL), precatalyst 10 (5 mol%),
and alkene (0.2 mmol). The reaction mixture was stirred at 25 ˚C.
After complete conversion (monitored by TLC), the reaction mixture
was passed through a cartridge containing activated acidic alumina
(pH ca. 9.5, 1-2 g). The cartridge was washed with an additional
portion of CH2Cl2 (10-20 mL). The
CH2Cl2 fraction was concentrated under reduced pressure
to yield the crude product.
14
Dräger G.
Dominguez XA.
Sanchez HV.
Gomez Lopez EG.
Kunst E.
Tsichritzis F.
Jeske F.
Jakupovic J.
Kirschning A.
Eur. J. Org. Chem.
2007,
5020
15a
Jasper C.
Adibekian A.
Busch T.
Quitschalle M.
Wittenberg R.
Kirschning A.
Chem.
Eur. J.
2006,
12:
8719
15b
Jasper C.
Wittenberg R.
Quitschalle M.
Jakupovics J.
Kirschning A.
Org.
Lett.
2005,
7:
479
16 Kirschning, A.; Harmrolfs, K.; Knobloch,
T. C. R. Chim., 2008,
in press, DOI: 10.1016/j.crci.2008.02.006.
17a
Meyer A.
Kirschning A.
Synlett
2007,
1264
17b
Meyer A.
Brünjes M.
Taft F.
Frenzel T.
Sasse F.
Kirschning A.
Org. Lett.
2007,
9:
1489
18
Kirschning A.
Harmrolfs K.
Mennecke K.
Messinger J.
Schön U.
Grela K.
Tetrahedron Lett.
2008,
49:
3019
