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DOI: 10.1055/s-0029-1219187
Synthesis and Catalytic Activity of Novel Benzimidazolinylidene-Ruthenium(II) Complexes
Publication History
Publication Date:
11 January 2010 (online)
Abstract
The reaction of [RuCl2(p-cymene)]2 with 1,3-dialkylbenzimidazolium salts 1a-d in the presence of a small excess of cesium carbonate yields chelated η6-arene, η¹-carbene ruthenium complexes 2a-d. All compounds were characterized by elemental analysis, NMR spectroscopy and the molecular structures of two of the complexes were determined by X-ray crystallography. The catalytic activity of RuCl2(η6-arene, η¹-benzimidazolinylidene) complexes was evaluated in the direct arylation of 2-phenylpyridine with bromobenzene derivatives.
Key words
ruthenium - benzimidazolinylidene complexes - N-heterocyclic carbene - C-H bond activation - arylation
- 1
Öfele K. J. Organomet. Chem. 1968, 12: P42 - 2
Wanzlick HW.Schonherr HJ. Angew. Chem., Int. Ed. Engl. 1968, 7: 141 - 3
Arduengo AJ.Harlow RL.Kline M. J. Am. Chem. Soc. 1991, 113: 361 -
4a
Cardin DJ.Cetinkaya B.Lappert MF. Chem. Rev. 1972, 72: 545 -
4b
Bourissou D.Guerret O.Gabbai FP.Bertrand G. Chem. Rev. 2000, 100: 39 -
4c
Hahn FE. Angew. Chem. Int. Ed. 2006, 45: 1348 -
4d
Peris E.Crabtree RH. Coord. Chem. Rev. 2004, 248: 2239 -
4e
Corberán R.Marzá EM.Peris E. Eur. J. Inorg. Chem. 2009, 13: 1700 -
4f
Marion N.Frémont P.Puijk IM.Ecarnot EC.Amoroso D.Bell A.Nolan SP. Adv. Synth. Catal. 2007, 349: 2380 -
4g
Hahn FE.Jahnke MC. Angew. Chem. Int. Ed. 2008, 47: 3122 - 5
Grubbs RH. Tetrahedron 2004, 60: 7117 -
6a
Özdemir I.Yaºar S.Çetinkaya B. Transition Met. Chem. 2005, 30: 831 -
6b
Yig M.it Yi B.it Özdemir I.Çetinkaya E.Çetinkaya B. Appl. Organomet. Chem. 2006, 20: 322 -
6c
Türkmen H.Pape T.Hahn FE.Çetinkaya B. Eur. J. Inorg. Chem. 2008, 5418 -
7a
Çetinkaya B.Özdemir I.Bruneau C.Dixneuf PH. J. Mol. Catal. A: Chem. 1997, 118: L1 -
7b
Çetinkaya B.Gürbüz N.Seçkin T.Özdemir I. J. Mol. Catal. A: Chem. 2002, 184: 31 -
8a
Mata JA.Poyatos M.Peris E. Coord. Chem. Rev. 2007, 251: 841 -
8b
Normand AT.Cavell KJ. Eur. J. Inorg. Chem. 2008, 2781 -
8c
Jahnke MC.Hahn FE.Pape T. Z. Naturforsch., B 2007, 62: 357 -
8d
Hahn FE.Jahnke MC.Pape T. Organometallics 2007, 26: 150 -
8e
Yen SK.Koh LL.Hahn FE.Huynh HV.Hor TSA. Organometallics 2006, 25: 5105 -
8f
Huynh HV.Holtgrewe C.Pape T.Koh LL.Hahn FE. Organometallics 2006, 25: 245 -
8g
Hahn FE.Jahnke MC.Gomez-Benitez V.Morales-Morales D.Pape T. Organometallics 2005, 24: 6458 -
8h
Bedford RB.Cazin CSJ.Holder D. Coord. Chem. Rev. 2004, 248: 2283 -
8i
Marion N.Navarro O.Mei J.Stevens ED.Scott NM.Nolan SP. J. Am. Chem. Soc. 2006, 128: 4101 -
8j
Shore G.Morin S.Mallik D.Organ MG. Chem. Eur. J. 2008, 14: 1351 -
8k
Hartmann CE.Nolan SP.Cazin CSJ. Organometallics 2009, 28: 2915 -
8l
Zanardi A.Mata JA.Peris E. Organometallics 2009, 28: 1480 -
8m
Marion N.Nolan SP. Acc. Chem. Res. 2008, 41: 1440 -
8n
Würtz S.Glorius F. Acc. Chem. Res. 2008, 41: 1523 -
9a
Lappert MF.Maskell RK. J. Organomet. Chem. 1984, 264: 217 -
9b
Yi M.git Özdemir I.Çetinkaya B.Çetinkaya E. J. Mol. Catal. A: Chem. 2005, 241: 88 -
9c
Özdemir I.Demir S.Şahin O.Büyükgüngör O.Çetinkaya B. Appl. Organomet. Chem. 2008, 22: 59 -
10a
Yamamoto YE.Negishi E. J. Organomet. Chem. 1999, 576: 1 -
10b
Stille JK. Angew. Chem., Int. Ed. Engl. 1986, 25: 508 -
10c
Miyaura N.Suzuki A. Chem. Rev. 1995, 95: 457 -
10d
Suzuki A. J. Organomet. Chem. 1999, 576: 147 -
11a
Kakiuchi F.Chatani N. Adv. Synth. Catal. 2003, 345: 1077 -
11b
Miura M.Nomura M. Top. Curr. Chem. 2002, 219: 212 -
11c
Özdemir I.Demir S.Çetinkaya B.Gourlaouen C.Maseras F.Bruneau C.Dixneuf PH.
J. Am. Chem. Soc. 2008, 130: 1156 -
12a
Satoh T.Kawamura Y.Miura M.Nomura M. Angew. Chem., Int. Ed. Engl. 1997, 36: 1740 -
12b
Terao Y.Wakui H.Satoh T.Miura M.Nomura M. J. Am. Chem. Soc. 2001, 123: 10407 -
12c
Bedford RB.Limmert ME.
J. Org. Chem. 2003, 68: 8669 -
12d
Oi S.Watanabe SI.Fukita S.Inoue Y. Tetrahedron Lett. 2003, 44: 8665 -
12e
Ackermann L.Mulzer M. Org. Lett. 2008, 10: 5043 -
13a
Oi S.Fukita S.Hirata N.Watanuki N.Miyano S.Inoue Y. Org. Lett. 2001, 3: 2579 -
13b
Kakiuchi F.Kan S.Igi K.Chatani N.Murai S. J. Am. Chem. Soc. 2003, 125: 1698 -
13c
Oi S.Aizawa E.Ogino Y.Inoue Y.
J. Org. Chem. 2005, 70: 3113 -
13d
Özdemir I.Demir S.Gürbüz N.Çetinkaya B.Toupet L.Bruneau C.Dixneuf PH. Eur. J. Inorg. Chem. 2009, 1942 -
14a
Okazawa T.Satoh T.Miura M.Nomura M. J. Am. Chem. Soc. 2002, 124: 5286 -
14b
Ackermann L. Synthesis 2006, 1557 -
14c
Gracias V.Gasiecki AF.Pagano TG.Djuric SW. Tetrahedron Lett. 2006, 47: 8873 -
14d
Ackermann L.Althammer A. Angew. Chem. Int. Ed. 2007, 46: 1627 ; and references cited therein -
14e
Lewis JC.Wiedemann SH.Bergman RG.Ellman JA. Org. Lett. 2004, 6: 35 -
15a
In Ruthenium
in Organic Synthesis
Kakiuchi F.Chatani N.Murahashi SI. Wiley-VCH; Weinheim: 2004. p.219 -
15b
Oi S.Sato H.Sugawara S.Inoue Y. Org. Lett. 2008, 10: 1823 -
15c
Ackermann L.Novák P.Vivente R.Hofmann N. Angew. Chem. Int. Ed. 2009, 48: 1 -
15d
Oi S.Funayama R.Hattori T.Inoue Y. Tetrahedron 2008, 64: 6051 -
15e
Po˛gan F.Dixneuf PH. Adv. Synth. Catal. 2009, 351: 1737 - 16
Oi S.Ogino Y.Fukita S.Inoue Y. Org. Lett. 2002, 4: 1783 - 17
Fukuyama T.Chatini N.Tatsumi J.Kakiuchi F.Murai S. J. Am. Chem. Soc. 1998, 120: 11522 - 18
Moore EJ.Pretzer WR.O’Connell TJ.Harris J.LaBounty L.Chou L.Grimmer SS. J. Am. Chem. Soc. 1992, 114: 5888 -
19a
Ackermann L. Org. Lett. 2005, 7: 3123 -
19b
Ackermann L.Vicente R.Althammer A. Org. Lett. 2008, 10: 2299 -
19c
Ackermann L.Althammer A.Born R. Tetrahedron 2008, 64: 6115 -
19d
Ackermann L.Althammer A.Born R. Synlett 2007, 2833 -
20a
Çetinkaya B.Demir S.Ozdemir I.Toupet L.Semeril D.Bruneau C.Dixneuf PH. Chem. Eur. J. 2003, 9: 2323 -
20b
Arslan H.VanDerveer D.Ozdemir I.Demir S.Çetinkaya B. Acta Crystallogr., Sect. E 2009, 65: m97 -
22a
Özdemir I.Demir S.Çetinkaya B.Toupet L.Castarlenas R.Fischmeister C.Dixneuf PH. Eur. J. Inorg. Chem. 2007, 2862 -
22b
Çetinkaya B.Özdemir I.Dixneuf PH. J. Organomet. Chem. 1997, 534: 153 - 23
Sheldrick GM. Acta Crystallogr., Sect. A 2008, 64: 112 - 24
Farrugia LJ. J. Appl. Crystallogr. 1999, 32: 837
References and Notes
General Method
for the Preparation of Ruthenium Complexes 2a-d: A suspension of benzimidazolium salt 1a-d (2.10
mmol), Cs2CO3 (2.14 mmol)and [RuCl2 (p-cymene)]2 (0.82
mmol) was heated under reflux in degassed toluene (20 mL) for 7
h. The reaction mixture was then filtered while hot, and the volume
was reduced to about 10 mL before addition of n-hexane
(15 mL). The precipitate formed was crystallized from CH2Cl2-hexane
(5 mL/15 mL) to give brown crystals. Crystals suitable
for single-crystal X-ray diffraction were obtained from CHCl3-Et2O.
RuCl
2
[η
¹
-CN{CH
2
(
η
6
-C
6
H
2
(
OMe)
3
-3,4,5)}C
6
H
4
N(CH
2
C
6
H
4
(
CMe
3
-
p
)] (2a):
Yield: 78% (0.96 g); mp 238-239 ˚C. IR:
1439 (CN) cm-¹. ¹H
NMR (399.9 MHz, CDCl3): δ = 7.18, 7.03
(m, 8 H, NC6H4N, CH2C6
H
4CMe3-p), 5.75 [m, 2 H, CH2C6
H
2(OMe)3-3,4,5], 5.07,
4.88 [s, 4 H, CH
2C6H2(OMe)3-3,4,5,
CH
2C6H4C(Me)3-p], 4.07, 4.27 [s,
9 H, CH2C6H2(OCMe)3-3,4,5],
1.27 (s, 9 H, CH2C6H4CMe
3-p). ¹³C
NMR (100.5 MHz, CDCl3): δ = 185.7 (Ccarbene),
97.2, 97.5, 109.0, 109.3, 109.6, 113.0, 122.9, 123.4, 125.0, 127.6,
133.2, 133.3, 135.1, 138.1, 138.4, 150.0 [CH2
C
6H2(OMe)3-3,4,5,
CH2
C
6H4CMe3-p, NC6H4N],
57.9, 58.1 [CH2C6H2(OMe)3-3,4,5], 55.7 [CH2C6H2(OMe)3-3,4,5],
53.4 (CH2C6H4CMe3-p), 34.4 (CH2C6H4
CMe3-p), 31.3
(CH2C6H4CMe
3-p). Anal. Calcd for C28H32N2O3RuCl2: C,
54.55; H, 5.23; N, 4.54. Found: C, 54.58; H, 5.20; N: 4.58.
RuCl
2
[η
¹
-CN{CH
2
(
η
6
-C
6
H
2
(
OMe)
3
-3,4,5)}C
6
H
4
N(CH
2
C
6
H
2
(
OMe)
3
-3,4,5)] (2b):
Yield: 82% (1.26 g); mp 196-197 ˚C. IR:
1441 (CN) cm-¹. ¹H
NMR (399.9 MHz, CDCl3): δ = 7.09 (s,
4 H, NC6H4N), 6.43 [s, 4 H, CH2C6
H
2(OMe)3-3,4,5],
6.13, 6.04 [s, 4 H, CH
2C6H2(OMe)3-3,4,5],
3.73, 3.81 [s, 18 H, CH2C6H2(OMe)3-3,4,5]. ¹³C
NMR (100.5 MHz, CDCl3): δ = 191.7 (Ccarbene),
104.6, 112.0, 123.5, 132.9 (NC6H4N), 135.8, 137.9,
153.8, 154.0 [free CH2
C
6H2(OMe)3-3,4,5],
56.7, 61.2 [CH2C6H2(OMe)3-3,4,5], 53.6 [CH2C6H2(OMe)3-3,4,5]. Anal.
Calcd for C27H30N2O6RuCl2˙CHCl3:
C, 43.68; H, 4.06; N, 3.64. Found: C, 43.72; H, 4.09; N: 3.68.
RuCl
2
[η
¹
-CN{CH
2(
η
6
-C
6
H
2
Me
3
-2,4,6)}C
6
H
4
N(CH
2
CH
2
OEt)] (2d): Yield: 70% (0.69
g); mp 293-294 ˚C. IR: 1436 (CN) cm-¹. ¹H
NMR (399.9 MHz, CDCl3): δ = 7.28-7.77
(m, 4 H, C6H4N), 5.59 (s, 2 H, CH2C6
H
2Me3-2,4,6), 5.03
(s, 2 H, CH
2C6H2Me3-2,4,6),
4.63 (t, 2 H, J = 5.0 Hz, CH
2CH2OEt), 3.77
(t, 2 H, J = 5.0 Hz, CH2CH
2OEt), 3.40 (q, 2 H, J = 7.0 Hz, OCH
2Me),
2.13, 2.36 (s, 9 H, CH2C6H2
Me
3-2,4,6), 1.08 (t, 3 H, J = 7.0 Hz, OCH2
Me). ¹³C
NMR (100.5 MHz, CDCl3): δ = 184.9 (Ccarbene),
109.4, 113.8, 123.2, 123.8, 132.8, 135.9 (NC6H4N),
89.7, 92.8, 98.9, 101.0 (CH2
C
6H2Me3-2,4,6), 72.1
(CH2
CH2OEt), 66.4
(CH2CH2OEt), 48.1 (CH2CH2OEt),
45.1 (CH2C6H2Me3-2,4,6),
16.9, 17.4 (CH2C6H2Me3-2,4,6),
15.3 (OCH2
CH3).
Anal. Calcd for C21H26N2ORuCl2:
C, 51.01; H, 5.30; N, 5.67. Found: C, 51.10; H, 5.35; N: 5.65.
General Procedure for the Arylation of 2-Phenyl-pyridine:
Ruthenium complex 2 (0.025 mmol), 2-phenylpyridine
(0.5 mmol), aryl bromide (1.25 mmol) and Cs2CO3 (1.50
mmol) were stirred in NMP (2 mL) at 120 ˚C for 20 h. H2O
and EtOAc were added to the cold reaction mixture. The organic phase
was separated, dried over MgSO4, filtered and concentrated
under vacuum. The remaining residue was purified by column chromatography on
silica gel (pentane-Et2O mixture) to yield the ortho-arylated products. Conversions
and product ratios were determined by ¹H NMR
and by GC analyses.
X-ray Structure
Determination of 2b and 2d: Brown single crystals of 2b and 2d suitable
for data collection were selected and data collection was performed
on a STOE IPDS II diffractometer with graphite monochromated Mo-Kα radiation
at 296 K. The structures were solved by direct-methods using SHELXS-97²³ and
refined by full-matrix least-squares methods on F
² using
SHELXL-97²³ from within the WINGX²4 suite
of software. All non-hydrogen atoms were refined with anisotropic
parameters. Hydrogen atoms were added to the structure models on
calculated positions.
Selected Crystallographic
Details for 2b: C28H31Cl5N2O6Ru, M = 769.87, brown crystal, 0.48 × 0.30 × 0.06
mm³, monoclinic, space group P21/c, a = 15.9602
(14), b = 13.9350 (10), c = 16.6111 (15) Å, β = 119.790 (6)˚, V = 3206.2 (5) ų, ρ
calcd = 1.595
g cm-³, µ = 0.95
mm-¹, empirical absorption correction
(0.723£ T £0.956), Z = 4, 18476 intensities collected
(± h, ± k, ± l),
6267 independent intensities (R
int = 0.062),
refinement of 383 parameters against all unique |F²|, R = 0.047, wR = 0.111
for 4099 contributing intensities [I £ 2σ(I)].
Selected
Crystallographic Details for 2d: C21H26Cl2N2ORu, M = 494.41, brown crystal, 0.48 × 0.33 × 0.11
mm³, monoclinic, space group C2/c, a = 30.4767
(18), b = 9.8695 (4), c = 14.8978 (8) Å, β = 108.484 (4)˚, V = 4249.9 (4) ų, ρ
calcd = 1.545
g cm-³, µ = 1.00
mm-¹, empirical absorption correction
(0.565£ T £0.914), Z = 8, 29964 intensities collected
(± h, ± k, ± l),
5022 independent intensities (R
int = 0.040),
refinement of 247 parameters against all unique |F²|, R = 0.025, wR = 0.063
for 3897 contributing intensities [I £ 2σ(I)].
Crystallographic
data (excluding structure factors) have been deposited with the
Cambridge Crystallographic Data Centre as supplementary publication
(CCDC 72906 for 2b and CCDC 72907 for 2d). Copies of the data can be obtained free
of charge via www.ccdc.cam.ac.uk/data.request/cif.