A bis(ortho-amine)aryl-gold(I) compound as an efficient, nontoxic, arylating reagent

Article abstract of DOI:10.1021/om020286b

A novel strategy for the synthesis of bis(ortho-amine)chelated monoanionic bisaminoaryl-metal complexes is presented. This method constitutes the exchange of a monoanionic, NCN-pincer ligand (NCN = [C₆H₃(CH₂NMe₂)₂-2,6] ^-) between a stable arylgold(I) phosphine, [Au(η¹-C-NCN)(PPh₃)] (2), and a transition metal halide. This transmetalation results in the quantitative formation of[M(NCN)] organometallic compounds (M = Au^III, Ni^II, Pd^II, Pt^II, Ti^IV, and Fe^III) and [AuCl(PPh₃)] as the only coproduct that can be recovered.

Full text of DOI:10.1021/om020286b

4556
Organometallics 2002, 21, 4556-4559
A Bis(or th o-a m in e)a r yl-Gold (I) Com p ou n d a s a n
Efficien t, Non toxic, Ar yla tin g Rea gen t
Maria Contel,† Marianne Stol,† Miguel A. Casado,† Gerard P. M. van Klink,†
Dianne D. Ellis,‡ Anthony L. Spek,‡,# and Gerard van Koten*,†
Debye Institute, Department of Metal-Mediated Synthesis, Utrecht University, Padualaan 8,
3584 CH Utrecht, The Netherlands, and Bijvoet Center for Biomolecular Research,
Department of Crystal and Structural Chemistry, Utrecht University,
Padualaan 8, 3584 CH Utrecht, The Netherlands
Received April 11, 2002
Summary: A novel strategy for the synthesis of bis(ortho-
amine)chelated monoanionic bisaminoaryl-metal com-
plexes is presented. This method constitutes the exchange
of a monoanionic, NCN-pincer ligand (NCN ) [C6H3(CH2-
NMe2)2-2,6]-) between a stable arylgold(I) phosphine,
[Au(η1-C-NCN)(PPh3)] (2), and a transition metal halide.
This transmetalation results in the quantitative forma-
Resu lts a n d Discu ssion
Recently, we prepared a gold(I) dimer [Au(NCN)]2 (1)5
and considered its use as a transmetalating reagent.
Although preliminary results with PdII and NiII com-
plexes were promising, the instability of 1 prevented the
production of the transmetalated products in reasonable
yields and purity.
It turned out, however, that [Au(NCN)(PPh3)] (2)
showed excellent properties in transmetalation reac-
tions with AuIII, MII (M ) Ni, Pd, Pt), FeIII, and TiIV
halide-containing precursors. To our knowledge this is
the first demonstration of an organogold compound to
cleanly transfer its organic group to other d10, d8, d5, or
d0 metallic centers. In all cases, the reaction afforded
the corresponding [M(NCN)] organometallic compound,
while [AuCl(PPh3)] was obtained as the recyclable
coproduct.
tion of [M(NCN)] organometallic compounds (M ) AuIII
,
NiII, PdII, PtII, TiIV, and FeIII) and [AuCl(PPh3)] as the
only coproduct that can be recovered.
In tr od u ction
Common methods to form transition metal to carbon
bonds generally involve the use of organolithium1 or
-magnesium2 reagents. When these reagents are not
appropriate or successful, e.g., because of their reducing
nature, organometallic reagents based on tin(IV), thal-
lium(I), or mercury(II) are available for the same
purpose. However, due to the considerable toxicity of
these metals, there is a strong tendency to restrict the
use of such reagents. Consequently, new approaches are
required to complement the synthetic palette. In view
of the isolobal relationship3 between AuL+ and Li+ and
the inertness of gold(I), we anticipated that the trans-
metalating properties of organogold(I) compounds (of the
type [AuRL]) could complement those of the correspond-
ing organolithium (LiR) reagents.4 This new approach
forms M-C bonds with the additional advantage of
recovering the starting gold(I) coproduct, which subse-
quently can be recycled into the starting organogold(I)
reagent.
The reaction of [AuCl(PPh3)] with [Li(NCN)]6 in Et2O
at -20 °C (Scheme 1) afforded the bis(ortho-amine)aryl-
gold(I) compound [Au(NCN)(PPh3)] (2) in good (68%) to
excellent yields (quantitative). The gold atom in 2 is η1-C
bonded to Cipso of the pincer moiety and is trans-
coordinated to the PPh3 ligand (Figure 1). Both ortho-
Me2NCH2 ligands are noncoordinated. In contrast to
[Au(NCN)]2 (1),5 2 is not light sensitive and is stable to
prolonged heating to 100 °C. Furthermore, 2 is soluble
in most organic solvents, is air and moisture stable, and
can be stored as a solid for months without any
noticeable decomposition.
The preparation of NCN‚M complexes by this new
method is outlined in Scheme 1. The use of 2 as an
* To whom correspondence should be addressed. Tel: +3130
2533120. Fax: +3130 2523615. E-mail: g.vankoten@chem.uu.nl.
† Debye Institute, Utrecht University.
(5) Contel, M.; Nobel, D.; Spek, A. L.; van Koten, G. Organometallics
2000, 19, 3288-3295.
(6) Steenwinkel, P.; J astrzebski, J . T. B. H.; Deelman, B.-J .; Grove,
D. M.; Kooijman, H.; Veldman, N.; Smeets, W. J . J .; Spek, A. L.; van
Koten, G. Organometallics 1997, 16, 5486-5498.
‡ Bijvoet Center for Biomolecular Research, Utrecht University.
#
Address correspondence pertaining to crystallographic studies to
this author. E-mail: A.L.Spek@chem.uu.nl.
(1) Wakefield, B. J . Best Synthetic Methods. Organolithium Methods;
Academic Press: London, 1988.
(2) Grignard Reagents, New Developments; Richey, H. G., Ed.;
Wiley: Chichester, U.K., 2000.
(3) (a) Lauher, J . W.; Wald, K. J . Am. Chem. Soc. 1981, 103, 7648-
7650. (b) Kudo, H. Nature 1992, 355, 432-434.
(4) We are aware of reactions in which compounds of the type
[AuRL] (R ) Mes, L ) PPh3, AsPh3, dppe) react cleanly with HgX2
salts (X ) halide) to give [HgRX] or [HgR2] organomercurial derivatives
and [AuClL] complexes as subproducts (refs 4a, 4b) or heteronuclear
complexes such as [HgCl(o-C6H4PPh2AuCl)] depending on the nature
of R (ref 4c). See: (a) Gregory, B. J .; Ingold, C. K. J . Chem. Soc. (B)
1969, 276-289. (b) Contel, M. Thesis, Universidad Pu´blica de Navarra,
Pamplona, 1996. (c) Bennett, M. A.; Bhargava, S. K.; Griffiths, K. D.;
Robertson, G. B.; Wickramasinghe, W. A.; Willis, A. C. Angew. Chem.
1987, 99, 261-262; Angew. Chem., Int. Ed. Engl. 1987, 26, 258-259.
(7) Grove, D. M.; van Koten, G.; Mul, P.; Zoet, R.; van der Linden,
J . G. M.; Legters, J .; Schmitz, J . E. J .; Murral, N. W.; Welch, A. J .
Inorg. Chem. 1988, 27, 2466-2473.
(8) Grove, D. M.; van Koten, G.; Louwen, J . N.; Noltes, J . G.; Spek,
A. L.; Ubbels, H. J . C. J . Am. Chem. Soc. 1982, 104, 6609-6616.
(9) (a) Smith, A. K. In Comprehensive Organometallic Chemistry II;
Abel, E. W., Stone, F. G. A., Wilkinson, G., Eds.; Pergamon: Oxford,
1995; Vol. 9, pp 29-106, and references therein. (b) Canty, A. J . In
Comprehensive Organometallic Chemistry II; Abel, E. W., Stone, F.
G. A., Wilkinson, G., Eds.; Pergamon: Oxford, 1995; Vol. 9, pp 225-
290, and references therein. (c) Anderson, G. K. In Comprehensive
Organometallic Chemistry II; Abel, E. W., Stone, F. G. A., Wilkinson,
G., Eds.; Pergamon: Oxford, 1995; Vol. 9, pp 431-531, and references
therein.
(10) Donkervoort, J . G.; J astrzebski, J . T. B. H.; Deelman, B.-J .;
Kooijman, H.; Veldman, N.; Spek, A. L.; van Koten, G. Organometallics
1997, 16, 4174-4184.
10.1021/om020286b CCC: $22.00 © 2002 American Chemical Society
Publication on Web 09/14/2002

Notes
Organometallics, Vol. 21, No. 21, 2002 4557
Sch em e 1. Tr a n sm eta la tion Rea ction s of [Au (NCN)(P P h 3)] (2). [Au Cl(P P h 3)] Wa s Obta in ed a s a Recycla ble
Cop r od u ct in All Ca sesa
a
Molar ratio, 1:1. (a) AuCl(tht), -tht, toluene, 0 °C; (b) AuCl3(tht), -tht, toluene, RT; (c) 4, [NiCl2(PPh3)2], -PPh3, toluene, RT;
5, [PdCl2(SEt2)2], -SEt2, toluene, RT; 6, [PtCl2(SEt2)2], -SEt2, toluene, gentle reflux, 2 h; (d) 7, [TiCl3(OCHMe2)], THF, -78 °C;
(e) FeCl3 (anhydrous), toluene, RT.
in 2, this approach does not affect the oxidation state
of the metallic centers involved during the transmeta-
lation processes. In addition, this method circumvents
the use of environmentally unacceptable Hg and Tl
analogues, while the [AuCl(PPh3)] coproduct can be
reused and converted back into 2, thus making this also
an atom-efficient method.
It must be noted that the known [M(NCN)Ln] com-
pounds 1 (AuI),5 4 (NiII),7 5 (PdII), and 6 (PtII)8 have been
synthesized via organolithium or Grignard reagents.
However in a number of cases, alternative methods such
as the use of other organometallic reagents or oxidative
addition of C-X bonds (which requires the preparation
of the corresponding aryl halides) to zerovalent metals
are required in order to avoid reduction to metallic Ni
or Pd or to prevent the formation of mixtures.9
Other (early) transition metals can also be incorpo-
rated by use of 2. For example, the synthesis of tita-
nium(IV) derivative 710 and iron(III) compound [FeCl2-
(NCN)] (8)11 was achieved on small scales. Moreover,
using 2 only one chloride ligand can be selectively
substituted.
F igu r e 1. Displacement ellipsoid plot (50% probability)
for one of the two crystallographic independent molecules
of 2. Selected bond lengths (Å) and angles (deg): Au1-C1
2.055(9), Au1-P1 2.282(2), Au2-C51 2.045(9), Au2-P2
2.287(2), C1-Au-P1 178.6(3), C51-Au2-P2 176.0(3).
The formation of paramagnetic 8 (from 2 and anhy-
drous FeCl3 in toluene at RT, Scheme 1) was confirmed
by X-ray diffraction techniques, and the spectroscopic
details were in accordance with earlier results.11 Using
the present gold(I) route the reaction can be carried out
on millimolar scale (0.55 mmol), and 8 can be obtained
in good yield. Moreover, this reaction can be performed
at RT, which underlines the nonreductive character of
2 giving an easy access to the formation of C-FeIII
bonds.
arylating reagent has certain advantages over tradi-
tional organolithium or Grignard reagents. The trans-
metalation reactions can be performed in air and even
at reflux depending on the metal involved (see Scheme
1). The NCN‚M complexes formed can be easily sepa-
rated from the coproduct by extraction with Et2O (in
which [AuCl(PPh3)] is insoluble) or by using conven-
tional fractional crystallization techniques. The reac-
tions do not require excess transmetalating reagent and
can be carried out in an exact 1:1 molar ratio. For air
and moisture sensitive products, reactions at millimolar
scale with [Li(NCN)] are often difficult because of the
manipulation of small amounts of sensitive [Li(NCN)].
Isolated yields of 3-8 range from 65 to 95%. Due to the
stability of the formal oxidation state of the Au center
The preparation of gold(III) compound [AuCl(NCN)]-
Cl (3) is of interest, as arylgold(III) derivatives are
(11) de Koster, A.; Kanters, J . A.; Spek, A. L.; van der Zeijden, A.
A. H.; van Koten, G.; Vrieze, K. Acta Crystallogr., Sect. C (Cryst. Struct.
Commun.) 1985, 41, 893-895.

4558 Organometallics, Vol. 21, No. 21, 2002
Notes
commonly not accessible by organolithium or Grignard
routes due to undesired reductions of gold(III) to
gold(I). Existing routes involve (i) oxidation of the
corresponding gold(I) compound with halogens, (ii)
electrophilic substitution by gold(III) at the aromatic
ring of benzene derivatives, or (iii) the use of other
partly undesirable organometallic reagents based on
SnIV, ZnII, TlI, or HgII.12 In case of arylgold(III) com-
plexes with coordinating ortho-substituents the use of
organomercury compounds is usually the only choice,
as direct auration reactions toward arenes are inhibited
by the presence of these substituents.12,13 Moreover,
most of these reactions required forcing reaction condi-
tions and prolonged times. For example, [AuCl(NCN)]X
(X ) Hg2Cl6-) was prepared by reacting [HgCl(NCN)]
with NH4[AuCl4] at RT using long reaction times (48
h).14 The present method affords 3 instantaneously at
RT and in high yield (95%).
Exp er im en ta l Section
Gen er a l P r oced u r es a n d Ma ter ia ls. All reactions were
carried out using standard Schlenk techniques under an inert
nitrogen atmosphere unless stated otherwise. Et2O, toluene,
pentane, and hexanes were carefully dried and distilled from
sodium prior to use. All standard reagents were purchased
from Acros or Aldrich. 1H (300 MHz), 13C (75 MHz), and 31P
(121 MHz) NMR spectra were recorded on a Varian 300
spectrometer at 25 °C; chemical shifts are in ppm referenced
to residual solvent resonances. Elemental analyses were
performed by Dornis und Kolbe, Mikroanalytisches Labora-
torium, Mu¨lheim a.d. Ruhr, Germany.
Syn th esis of [Au (C6H3{CH2NMe2}2-2,6)(P P h 3)] (2). To a
solution of 0.52 g of NCHN (1,3-bis[(dimethylamino)methyl]-
benzene) (2.7 mmol) in 30 mL of pentane was added by syringe
1.7 mL of a 1.6 M solution of n-BuLi (2.7 mmol) in hexane.
After addition, stirring was continued for 16 h. The reaction
mixture turned yellow and was added, at -30 °C, to a
suspension of 1.33 g of [AuCl(PPh3)] (2.7 mmol) in 20 mL of
diethyl ether. After addition, stirring was continued for 15 min,
after which the reaction mixture was allowed to warm to room
temperature and stirred for another 4.5 h and subsequently
quenched with 35 mL of water. The reaction mixture was
filtered over Celite, the organic fraction was separated, and
the aqueous fraction was extracted with diethyl ether (2 × 35
mL). The extracts were combined, washed (water), dried
(MgSO4), filtered, and evaporated to dryness. The residual
solid was washed twice with pentane (10 mL). This afforded
1.5 g (2.3 mmol, 87%) of a cream-colored solid, which was
characterized as pure 2.
An important driving force of the reactions studied
(see Scheme 1) is most likely the formation of a strong
Au-Cl bond in the coproduct as well as the coordination
of the ortho-amino donor atoms in the products. More-
over, it can be envisaged that prior nitrogen-metal
coordination of the free amino substituents in 2 to the
metal salt assists in the transmetalation process.
Con clu sion
1H NMR (300 MHz, C6D6): δ 2.31 (s, 12H, NCH3), 4.03 (s,
4H, ArCH2), 6.97-7.01 (m, 9H, PArH), 7.37 (t, 3J ) 6.6 Hz,
1H, ArH), 7.58-7.76 (m, 8H, PArH + ArH). 31P{1H} NMR (121
MHz, C6D6, 25 °C): δ 44.9. 13C{1H} NMR (75 MHz, C6D6, 25
°C): δ 45.9 (CH3), 70.8 (CH2), 125.54, 130.83, 131.93, 132.56,
134.60, 148.05 (Cipso not observed). FAB(+): m/z (%) 651 (100).
Anal. Calcd for C30H34N2PAu: C, 55.39; H, 5.27; N, 4.31.
Found: C, 55.26; H, 5.22; N, 4.25.
A general synthetic method has been developed to use
stable arylgold(I) phosphine precursors as transmeta-
lating reagents in organometallic chemistry. It repre-
sents a nontoxic method with the possibility of perform-
ing reactions at air, generally at RT, in millimolar scale
without reduction of the transmetalated metal center.
In addition, the [AuCl(PPh3)] coproduct can be recovered
and with additional [Li(NCN)] transformed to starting
compound 2. The scope of this method is currently
studied using various types of ortho-substituted arylgold-
(I) phosphine precursors and a range of transition metal
compounds. This method complements nicely the re-
cently reported cyclotransmetalation reactions which
involve the exchange of an arene proton with a suitable
metal salt cation assisted by ortho-chelation.15 Both
methods are extremely important for the synthesis of
multimetallic systems such as the metallopincer cart-
wheel compounds.16
Syn th esis of [Au Cl(C6H3{CH2NMe2}2-2,6)][Cl] (3). To a
solution of [AuCl3(tht)] (192.6 mg, 0.492 mmol) in toluene (50
mL) was added a solution of 2 (319.6 mg, 0.491 mmol) in
toluene (15 mL). A pale yellow precipitate was formed readily,
which was separated from the colorless solution. Pale yellow
3 was then washed with Et2O and dried in vacuo (214.2 mg,
95% yield). The mother liquor was evaporated to dryness to
afford 237.5 mg of a white precipitate, which was characterized
as pure [AuCl(PPh3)] (0.480 mmol, 98%).
1H NMR (300 MHz, C6D6): δ 3.29 (s, 12H, NCH3), 4.70 (s,
2
4H, CH2), 7.07 (d, 2H, ArH), 7.34 (t, J ) 11.7 Hz, 1H, ArH).
13C{1H} NMR (75 MHz, CD3CN): δ 55.34 (CH3), 78.62 (CH2),
123.29, 130.57, 143.58 (Cipso not observed). FAB(+): m/z (%)
423 (50). Anal. Calcd for C12H19N2AuCl2: C, 31.39; H, 4.17;
N, 6.10. Found: C, 31.27; H, 4.25; N, 6.05.
(12) (a) Grohmann, A.; Schmidbaur, H. Comprehensive Organome-
tallic Chemistry II; Abel, E. W., Stone, F. G. A., Wilkinson, G., Eds.;
Pergamon: Oxford, 1995; Vol. 3, p 31. (b) Schmidbaur, H.; Grohmann,
A.; Olmos M. E. Gold: Progress in Chemistry, Biochemistry and
Technology; Wiley-VCH: Chichester, U.K., 1999; p 705.
Syn th esis of [NiCl(C6H3{CH2NMe2}2-2,6)] (4). To a purple-
red solution of [NiCl2(PPh3)2] (71.7 mg, 0.109 mmol) in benzene
(25 mL) was added 71.3 mg (0.109 mmol) of 2. The color of
the solution changed immediately to bright yellow. After
stirring for 30 min at RT, the solution was concentrated to
∼10 mL. Extraction with Et2O (10 mL) afforded a white
precipitate ([AuCl(PPh3)]) and an orange solution. This solu-
tion was concentrated to give 29.1 mg (0.102 mmol, 93%) of a
yellow solid, which was characterized by 1H NMR spectroscopy
as pure 4.
(13) For example: (a) Vicente, J .; Chicote, M. T.; Bermude´z, M. D.
Inorg. Chim. Acta 1982, 63, 35-39. (b) Vicente, J .; Chicote, M. T.;
Bermude´z, M. D. J . Organomet. Chem. 1984, 268, 191-195. (c) Vicente,
J .; Chicote, M. T.; Bermude´z, M. D.; J ones, P. G.; Fittschen, C.;
Sheldrick, G. M. J . Chem. Soc., Dalton Trans. 1986, 2361-2366. (d)
Vicente, J .; Bermude´z, M. D.; Carrio´n, F. J .; Martin-Nicola´s, G. J .
Organomet. Chem. 1994, 480, 103-109. (e) Parish, R. V.; Wright, J .
P.; Pritchard, R. G. J . Organomet. Chem. 2000, 596, 165-176. (f)
Contel, M.; Edwards, A. J .; Garrido, J .; Hursthouse, M. B.; Laguna,
M.; Terroba, R. J . Organomet. Chem. 2000, 607, 129-136.
(14) Bonnardel, P. A.; Parish, R. V.; Pritchard. R. G. J . Chem. Soc.,
Dalton Trans. 1996, 3185-3193.
(16) (a) Dijkstra, H. P.; Steenwinkel, P.; Grove, D. M.; Lutz, M.;
Spek, A. L.; van Koten, G. Angew. Chem. 1999, 111, 2322-2324;
Angew. Chem., Int. Ed. 1999, 38, 2185-2188. (b) Dijkstra, H. P.; Meijer,
M. D.; Patel, J .; Kreiter, R.; van Klink, G. P. M.; Lutz, M.; Spek, A. L.;
Canty, A. J .; van Koten, G. Organometallics 2001, 20, 3159-3168. (c)
Dijkstra, H. P.; Kruithof, C. A.; Ronde, N.; van de Coevering, R.;
Ramo´n, D. J .; Vogt, D.; van Klink, G. P. M.; van Koten, G. J . Org.
Chem. 2002, ASAP (J O0257602).
(15) (a) Dani, P.; Albrecht, M.; van Klink, G. P. M.; van Koten, G.
Organometallics 2000, 19, 4468-4476. (b) Albrecht, M.; Dani, P.; Lutz,
M.; Spek, A. L.; van Koten, G. J . Am. Chem. Soc. 2000, 122, 11822-
11833. (c) Dijkstra, H. P.; Albrecht, M.; van Koten, G. Chem. Commun.
2002, 126-127. (d) Hughes, R. P.; Williamson, A.; Incarvito, C. D.;
Rheingold, A. L. Organometallics 2001, 20, 4741-4744.

Notes
1H NMR (300 MHz, C6D6): δ 2.39 (s, 12H, NCH3), 3.01 (s,
4H, ArCH2), 6.46 (d, J ) 7.5 Hz, 2H, ArH), 6.98 (t, J ) 7.4
Hz, 1H, ArH). Anal. Calcd for C12H19N2NiCl: C, 50.89; H, 6.71;
N, 9.81. Found: C, 51.06; H, 6.78; N, 9.94.
Organometallics, Vol. 21, No. 21, 2002 4559
Ta ble 1. Cr ysta l Da ta a n d Deta ils of Str u ctu r e
Refin em en t for 2
3
3
Crystal Data
C30H34AuN2P
formula
Syn th esis of [P d Cl(C6H3{CH2NMe2}2-2,6)] (5). To a solu-
tion of 0.065 g (0.100 mmol) of 2 in toluene (10 mL) was added
0.036 g (0.10 mmol) of bright orange [PdCl2(SEt2)2]. Almost
immediately the color of the solution faded to pale yellow. The
solution was stirred for 30 min at RT, after which the solution
was concentrated. Upon addition of 10 mL of Et2O, 0.45 g (97%)
of a white precipitate was obtained, which was characterized
as pure [AuCl(PPh3)]. The solution was further concentrated
and pentane added, which afforded 0.0294 g (96%) of a white
fw
650.53
monoclinic
P21/c (No. 14)
9.2074(8), 21.4351(15), 28.801(4)
90, 108.511(9), 90
5390.1(10)
8
1.603
5.538
2576
0.25 × 0.44 × 0.50
cryst syst
space group
a, b, c [Å]
R, â, γ [deg]
V [Å3]
Z
D(calc) [g/cm3]
µ(Mo KR) [/mm]
F(000)
1
compound, which was characterized by H NMR spectroscopy
cryst size [mm]
as pure 5.
Data Collection
1H NMR (300 MHz, C6D6): δ 2.60 (s, 12H, NCH3), 3.28 (s,
temperature [K]
radiation [Å]
θ(min-max) [deg]
dataset
no. tot., uniq. data, R(int)
no. obsd data [I > 2.0σ(I)]
150
3
3
4H, ArCH2), 6.55 (d, J ) 7.5 Hz, 2H, ArH), 6.94 (t, J ) 7.6
Hz, 1H, ArH). Anal. Calcd for C12H19N2PdCl: C, 43.26; H, 5.75;
N, 8.41. Found: C, 43.41; H, 5.82; N, 8.47.
Mo KR 0.71073
0.8, 27.5
-3: 11; -27: 27; -37: 35
26 342, 12 339, 0.089
8541
Syn th esis of [P tCl(C6H3{CH2NMe2}2-2,6)] (6). In an
NMR tube 0.0040 g (0.0061 mmol) of 2 and 0.0027 (0.006
mmol) of [PtCl2(SEt2)2] were combined in 0.7 mL of deuterated
benzene. The solution was heated to reflux for 2 h, during
which it became colorless. 1H and 31P NMR spectroscopy
revealed only signals that could be ascribed to [AuCl(PPh3)],
6, and free SEt2.
Refinement
N
ref, Npar
12339, 627
0.0529, 0.1032, 0.99
R, wR2, S
w ) 1/[σ2(Fo2) + (0.0338P)2]
where P ) (Fo + 2Fc2)/3
2
3
1H NMR (300 MHz, C6D6): δ 2.69 (t, J PtH ) 19.1 Hz, 12H,
max. and av. shift/error
0.00, 0.00
-1.64, 1.41
min. and max. resd dens [e/Å3]
3
3
NCH3), 3.28 (t, J PtH ) 22.8 Hz, ArCH2), 6.64 (d, J ) 7.5 Hz,
3
2H, ArH), 7.04 (t, J ) 7.5 Hz, 1H, ArH).
Syn th esis of [TiCl2(C6H3{CH2NMe2}2-2,6)(OCHMe2)] (7).
To a colorless solution of 0.045 g (0.21 mmol) of TiCl3(OCHMe2)
in toluene was added dropwise, at -78 °C, 0.137 g (0.21 mmol)
of 2 in 10 mL of toluene. The mixture was stirred for 30 min,
after which it was allowed to warm to RT. After slight
concentration, a pale yellow precipitate formed. The mixture
was cooled overnight at -10 °C. The precipitate was separated
from the solution and characterized by 1H and 31P NMR
spectroscopy as pure [AuCl(PPh3)]. The mother liquor was
evaporated to dryness to afford 50.4 mg (65%) of a yellow
precipitate, which was characterized by 1H NMR spectroscopy
as pure 7.
latter using an empirical correction based on ∆F values (with
routine DELABS incorporated in PLATON).17 The structure
was solved with the DIRDIF97 program18 and refined with
SHELXL-97 using full matrix least-squares on F2.19 Data were
initially collected in the P21/n setting (â angle of 90.13°). The
structure was twinned along the a axis, thus a TWIN matrix
{-1 0 0 | 0 1 0 | 0 0 1} was applied with a BASF parameter
that refined to 0.269(1). The N3 and C59 displacement
ellipsoids in one of the two crystallographically independent
molecules are large and were modeled being disordered across
two sites in a ratio 65(1):35(1). The packing of the molecules
mimics Pbcn symmetry. Crystallographic data (excluding
structure factors) for 2 have been deposited with the Cam-
bridge Crystallographic Data Centre as supplementary pub-
lication no. CCDC 165228. Copies of the data can be obtained
free of charge on application to CCDC, 12 Union Road,
Cambridge CB21EZ, UK (fax: (+44) 1223-336-033; e-mail:
deposit@ccdc.cam.ac.uk).
1H NMR (300 MHz, C6D6): δ 1.21 (d, 3J ) 7.41 Hz, 6H,
OCH(CH)3), 2.1 (bs, 6H, NCH3), 2.6 (bs, 2H, ArCH2), 2.8 (bs,
6H, NCH3), 4.7 (bs, 2H, ArCH2), 5.88 (septet, 3J ) 6.22 Hz,
3
3
1H, OCH), 6.61 (d, J ) 7.40 Hz, 2H, ArH), 6.88 (t, J ) 7.41
Hz, 1H, ArH). Anal. Calcd for C15H26N2Cl2OTi: C, 48.80; H,
7.10; N, 7.59. Found: C, 48.91; H, 7.13; N, 7.52.
Syn th esis of [F eCl2(C6H3{CH2NMe2}2-2,6)] (8). To a dark
green solution of 0.090 g of FeCl3 (anhydrous) (0.56 mmol) in
degassed, dry toluene (10 mL) was added a solution of 0.322
g of 2 (0.56 mmol) in 5 mL of toluene. The color of the solution
slowly changed to dark orange. After 5 h stirring at RT the
toluene was removed in vacuo. Extraction with degassed, dry
Et2O (15 mL) afforded a white precipitate [AuCl(PPh3)] and a
light red solution that was transferred to another flask by
cannula. This solution was concentrated to ca. 5 mL, and
subsequent cooling (-20 °C) afforded 8 as dark brown needles
(0.14 g, 79%). Confirmation of the structure of 8 was obtained
by an X-ray diffraction study. The crystallographic date were
in agreement with a previously reported X-ray of 8.11
Cr ysta l Str u ctu r e Deter m in a tion of 2. A colorless block-
shaped crystal measuring (0.50 × 0.44 × 0.25 mm) was
mounted under a nitrogen stream (150 K) on an Enraf-Nonius
CAD4 diffractometer with a graphite monochromator (λ )
0.71073 Å) and a rotating anode source. The unit cell dimen-
sions were determined from the setting values of 25 accurately
centered reflections in the range 11.56° < θ < 13.76°. The
stability of the crystal was monitored by measuring the
intensities of three standard reflections every hour. Data were
corrected for Lorentz, polarization, and absorption effects, the
Ack n ow led gm en t. This research was supported in
part (D.D.E. and A.L.S.) by the Council for Chemical
Sciences of the Netherlands Organization for Scientific
Research (CW-NWO), in part (M.A.C.) by the National
Research School Combination Catalysis, and in part
(M.S.) by the Dutch Polymer Institute. M.C. is grateful
for a travel grant from the C.A.I-D.G.A., CB 15/00
(Programa Europa).
Su p p or tin g In for m a tion Ava ila ble: Details of the X-ray
crystal structure analysis of compound 2. This material is
available free of charge via the Internet at http://pubs.acs.org.
OM020286B
(17) Spek, A. L. PLATON. A Multipurpose Crystallographic Tool;
Utrecht University: The Netherlands, 2001.
(18) Beurskens, P. T.; Admiraal, G.; Beurskens, G.; Bosman, W. P.;
Garcia-Granda, S.; Gould, R. O.; Smits, J . M. M.; Smykalla, C.
DIRDIF97 Program System, Technical Report, Crystallography Labo-
ratory, University of Nijmegen, The Netherlands, 1997.
(19) Sheldrick, G. M. SHELXL-97, Programs for crystal structure
and refinement; University of Go¨ttingen: Germany, 1997.