Activation of acetonitrile in [Cp*Ir(η3-CH2CHCHPh)(NCMe)]+: Crystal structures of iridium-amidine, imino-ether, amido, and amide complexes

Article abstract of DOI:10.1021/om9908480

Reactions of [Cp*Ir(η³-CH₂CHCHPh)(NCMe)]OTf (1) with protic amines, alcohols, and water produce amidine complexes [Cp*Ir(η³-CH₂CHCHPh)(NH=C(NR₂)Me)]OTf (2) (R₂ = (Me)₂ (a), (Me)(H) (b), (i-Pr)(H) (c), (-CH₂(CH₂)₃CH₂-) (d)), imino-ether complexes [Cp*Ir-(η³-CH₂CHCHPh)(NH=C(OR′)Me)]OTf (4) (R′ = Me (a), Et (b), i-Pr (c)), and amido complex Cp*Ir(η³-CH₂CHCHPh)(NHC(=O)Me) (5-K), respectively. The keto form amido complex 5-K undergoes tautomerization to give the enol form complex Cp*Ir(η³-CH₂CHCHPh)(N= C(OH)Me) (5-E) in polar solvents. Tertiary amines (NMe₃, NEt₃) react with 1 in chlorinated solvents (XCl) to give the chloro complex Cp*IrCl(η³-CH₂CHCHPh) (3) and quaternary ammonium salts [R₃NX]OTf(R = Me, Et and X = CH₂Cl, CH₃, CHCl₂, CCl₃, PhCH₂). Crystal structures of 2a, 4a, 5-K, and [Cp*Ir(NH=C(OH)Me)(OH₂)(PPh₃)]OTf₂ (6) have been determined by single-crystal X-ray diffraction analysis, which lead us to suggest hybrid structures, Ir-^-NH-C(=N⁺Me₂)Me (2a′) for 2a and Ir-^-NH-C(=O⁺Me)Me (4a′) for 4a to some extent. Complexes 2 and 4 react with PPh₃ to give an iridium(III) complex [Cp*Ir(η³-CH₂CHCHPh)(PPh₃)]OTf (7) and the free amidines NH=C(NR₂)Me (8) and imino-ethers NH=C(OR′)Me (9), respectively. Nitrile complexes 1 and [Cp*Ir(η³-CH₂CHCHPh)(NCCH= CHMe)]OTf(10) catalyze the hydration of the nitriles in the presence of Na₂CO₃ to produce amides, and the benzonitrile complex [Cp*Ir(η³-CH₂CHCHPh)(NCPh)]OTf(11) catalyzes the methanolysis of benzonitrile in the presence of Na₂CO₃ to produce NH=C(OMe)Ph. Plausible mechanisms for these catalytic reactions are suggested with the amido and imino-ether complexes such as 4 and 5 being involved.

Full text of DOI:10.1021/om9908480

638
Organometallics 2000, 19, 638-648
Activa tion of Aceton itr ile in
[Cp *Ir (η3-CH2CHCHP h )(NCMe)]+: Cr ysta l Str u ctu r es of
Ir id iu m -Am id in e, Im in o-Eth er , Am id o, a n d Am id e
Com p lexes
Chong Shik Chin,*,† Daesung Chong,† Byeongno Lee,† Hyunmok J eong,†
Gyongshik Won,† Youngkyu Do,‡ and Young J a Park§
Chemistry Department, Sogang University, Seoul 121-742, Korea, Chemistry Department,
Korea Advance Institute of Science and Technology, 305-701 Taejeon, Korea, and
Chemistry Department, Sookmyung Women’s University, Seoul 140-742, Korea
Received October 22, 1999
Reactions of [Cp*Ir(η3-CH2CHCHPh)(NCMe)]OTf (1) with protic amines, alcohols, and
water produce amidine complexes [Cp*Ir(η3-CH2CHCHPh)(NHdC(NR2)Me)]OTf (2) (R2 )
(Me)2 (a ), (Me)(H) (b), (i-Pr)(H) (c), (-CH2(CH2)3CH2-) (d )), imino-ether complexes [Cp*Ir-
(η3-CH2CHCHPh)(NHdC(OR′)Me)]OTf (4) (R′ ) Me (a ), Et (b), i-Pr (c)), and amido complex
Cp*Ir(η3-CH2CHCHPh)(NHC(dO)Me) (5-K), respectively. The keto form amido complex
5-K undergoes tautomerization to give the enol form complex Cp*Ir(η3-CH2CHCHPh)(Nd
C(OH)Me) (5-E) in polar solvents. Tertiary amines (NMe3, NEt3) react with 1 in chlorinated
solvents (XCl) to give the chloro complex Cp*IrCl(η3-CH2CHCHPh) (3) and quaternary
ammonium salts [R3NX]OTf (R ) Me, Et and X ) CH2Cl, CH3, CHCl2, CCl3, PhCH2). Crystal
structures of 2a , 4a , 5-K, and [Cp*Ir(NHdC(OH)Me)(OH2)(PPh3)]OTf2 (6) have been
determined by single-crystal X-ray diffraction analysis, which lead us to suggest hybrid
structures, Ir--NH-C(dN+Me2)Me (2a ′) for 2a and Ir--NH-C(dO+Me)Me (4a ′) for 4a to
some extent. Complexes 2 and 4 react with PPh3 to give an iridium(III) complex [Cp*Ir(η3-
CH2CHCHPh)(PPh3)]OTf (7) and the free amidines NHdC(NR2)Me (8) and imino-ethers
NHdC(OR′)Me (9), respectively. Nitrile complexes 1 and [Cp*Ir(η3-CH2CHCHPh)(NCCHd
CHMe)]OTf (10) catalyze the hydration of the nitriles in the presence of Na2CO3 to produce
amides, and the benzonitrile complex [Cp*Ir(η3-CH2CHCHPh)(NCPh)]OTf (11) catalyzes the
methanolysis of benzonitrile in the presence of Na2CO3 to produce NHdC(OMe)Ph. Plausible
mechanisms for these catalytic reactions are suggested with the amido and imino-ether
complexes such as 4 and 5 being involved.
In tr od u ction
extensively studied with homogeneous catalysts8-12 and
heterogeneous catalysts.13-15 On the other hand, alco-
holysis and aminolysis of nitriles catalyzed by metal
compounds have not been previously reported.
While metal-coordinated nitriles (M-NtCR) in gen-
eral are so labile that they are readily replaced by many
other organic molecules, they also show higher reactivity
than free ones.1 Reactions between free nitriles and
nucleophiles such as amines, alcohols, and water usually
proceed in the presence of acid or base,2 whereas
coordinated nitriles react with those nucleophiles with-
out the help of an acid or base.3
Metal-amidine (M-NHdCR(NR2)), metal-imino-
ether (M-NHdCR(OR)), metal-amido (M-NHC(d
O)R), and metal-imine (M-NHdCHR) complexes have
been prepared from the reactions of M-NtCR with
HNR2,4 ROH,5 H2O,6 and LiEt3BH,7 respectively. Cata-
lytic hydration of nitriles to produce amides has been
(4) (a) Feng, S. G.; White, P. S.; Templeton, J . L. Organometallics
1993, 12, 1765, and referneces cited therein. (b) Rousselet, G.;
Capdevielle, P.; Maumy, M. Tetrahedron Lett. 1993, 34, 6395. (c)
Syamala, A.; Chakravarty, A. R. Inorg. Chem. 1991, 30, 4699. (d)
Fairlie, D. P.; J ackson, W. G. Inorg. Chem. 1990, 29, 140. (e) Paul, P.;
Nag, K. Inorg. Chem. 1987, 26, 1586. (f) Maresca, L.; Natile, G.; Intini,
F. P.; Gaparrini, F.; Tripicchio, A.; Tripicchio-Camellini, M. J . Am.
Chem. Soc. 1986, 108, 1180.
(5) (a) Fanizzi, F. P.; Intini, F. P.; Natile, G. J . Chem. Soc., Dalton
Trans. 1989, 947, and references therein. (b) Paul, P.; Nag, K. J . Chem.
Soc., Dalton Trans. 1988, 2373. (c) Casas, J . M.; Chisholm, M. H.;
Sicilia, M. V.; Streib, W. E. Polyhedron 1991, 10, 1573, and reference
therein.
(6) (a) Suh, M. P.; Oh, K. Y.; Lee, J . W.; Bae, Y. Y. J . Am. Chem.
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C.; Wickramasinghe, W. A.; Willis, A. C. Inorg. Chem. 1994, 33, 6425.
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1352. (f) Curtis, N. J .; Sargeson, A. M. J . Am. Chem. Soc. 1984, 106,
625. (g) Creaser, I. I.; Harrowfield, F. G.; Sargeson, A. M. J . Am. Chem.
Soc. 1981, 103, 3559. (h) Fairlie, D. P.; Ilan, Y.; Taube, H. Inorg. Chem.
1997, 36, 1029. (i) Parkins, A. W. Platinum Metals Rev. 1996, 40, 169.
(j) Failie, D. P.; Angus, P. M.; Fenn, M. D.; J ackson, W. G. Inorg. Chem.
1991, 30, 1564. (k) Angel, R. L.; Fairlie, D. P.; J ackson, W. G. Inorg.
Chem. 1990, 29, 20.
† Sogang University.
‡ Korea Advance Institute of Science and Technology.
§ Sookmyung Women’s University.
(1) (a) Michelin, R. A.; Mozzon, M.; Bertani, R. Coord. Chem. Rev.
1996, 147, 299. (b) Endres, H. In Comprehensive Coordination Chem-
istry; Willkinson, G., Gillard, R. D., McCleverty, J . A., Eds.; Perga-
mon: Oxford, 1987; Vol. 2, p 261. (c) Bryan, S. J .; Huggett, P. G.; Wade,
K.; Danials, J . A.; J ennings, J . R. Coord. Chem. Rev. 1982, 44, 149.
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(3) For example, see refs 1a,b and 4-13.
10.1021/om9908480 CCC: $19.00 © 2000 American Chemical Society
Publication on Web 01/26/2000

Acetonitrile in [Cp*Ir(η3-CH2CHCHPh)(NCMe)]+
Organometallics, Vol. 19, No. 4, 2000 639
During the investigation on the catalytic activity of
the iridium(III) complex [Cp*Ir(η3-CH2CHCHPh)(NCMe)]-
-
OTf (1) (Cp* ) C5Me5 and OTf ) -OSO2CF3),16 we
found that nucleophiles such as amines, alcohols, and
water are added to the coordinated MeCN of 1 to give
stable Ir-amidine, Ir-imino-ether, and Ir-amido com-
plexes. Organic molecules containing imino-ether and
amidine moieties are important as pharmaceutical
materials as well as intermediates in organic synthe-
ses.17 The hydration of nitrile groups can lead to the
preparation of useful monomers; for example, the hy-
drolysis of acrylonitrile affords acrylamide, of which
polymers are very important materials in paper produc-
tion and wastewater treatment.18
F igu r e 1. ORTEP drawing of [Cp*Ir(η3-CH2CHCHPh)-
(NHdC(NMe2)Me)]OTf (2a -E) with 30% thermal ellipsoids
probability. Selected bond distances (Å): Ir1-N1 ) 2.090-
(4); Ir1-C11 ) 2.144(6); Ir1-C12 ) 2.123(6); Ir1-C13 ) 2.233-
Resu lts a n d Discu ssion
Ad d ition of P r otic Am in es to MeCN in 1: Am i-
din e Com plex [Cp*Ir (η3-CH2CHCHP h )(NHdC(NR2)-
Me]OTf (2). Compound 1 reacts with protic amines
under refluxing condition to give stable amidine com-
plexes 2a -d (eq 1). The amine addition is much faster
in the presence of Na2CO3 than in the absence of Na2-
CO3.
(5); C11-C12 ) 1.393(8); C12-C13 ) 1.431(8); N1-C20
1.298(6); C20-N2 ) 1.347(6); N2-C22 ) 1.446(8); N2-C23
)
)
1.463(7); C20-C21 ) 1.500(7). Selected bond angles (deg):
Ir1N1C20 ) 133.1(4); N1C20C21 ) 120.4(5); N1C20N2 ) 121.8-
(5); C21C20N2 ) 117.8(4); C20N2C22 ) 120.8(5); C20N2C23
)
122.4(5). Counteranion (OTf) and hydrogen atoms are
omitted for clarity.
structure determination for [Cp*Ir(η3-CH2CHCHPh)-
(NHdC(NMe2)Me]OTf (2a ). The crystal structure analy-
sis for 2a reveals that the stable form is 2a -E, where
the NMe2 group is trans to Ir (Figure 1).
The bond distance of N(2)-C(20) (1.347(6) Å) of 2a is
somewhat shorter than the average value of N-C(sp2)
(1.38 Å)19 and significantly shorter than those of N(2)-
C(22) (1.446(8) Å), N(2)-C(23) (1.463(7) Å), and the
average value of N-C(sp3) (1.47 Å)19 (see Figure 1). The
bond distance of N(1)-C(20) (1.298(6) Å) on the other
hand is somewhat longer than the average value of Nd
C(sp2) (1.28 Å).19 The amidine moiety (NHdC(NMe2)-
Me) of 2a seems to be planar (planarity data of 6 atoms
are -0.004(4) Å for N(1), 0.001(5) Å for C(20), -0.007-
(4) Å for C(21), 0.038(5) Å for N(2), -0.016(4) Å for C(22),
and -0.012(4) Å for C(23)) with all the relevant bond
angles being close to 120°: N(1)-C(20)-C(21), 120.4-
(5)°; N(1)-C(20)-N(2), 121.8(5)°; N(2)-C(20)-C(21),
117.8(4)°; C(20)-N(2)-C(22), 120.8(5)°; C(20)-N(2)-
C(23), 122.4(5)°; C(22)-N(2)-C(23), 116.4(5)°.
These observations may be understood in terms of the
hybrid structures between the two species as shown in
eq 2. The same type of resonance structure has been
suggested for Pt complexes based on spectral and
crystallographic data.4d,f The isomerization of 2a -E to
2a -Z has not been observed even under reflux conditions
in CH2Cl2. All other amidine complexes (2b-d ) were
prepared in refluxing CH2Cl2, and no Z isomers have
been observed.
The amidine complexes have been characterized by
spectral (1H, 13C NMR, and IR) data and by crystal
(7) (a) Feng, S. G.; Templeton, J . L. Organometallics 1992, 11, 1295.
(b) Feng, S. G.; Templeton, J . L. J . Am. Chem. Soc. 1989, 111, 6477.
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108, 7846.
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Inorg. Chem. 1983, 22, 4038.
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N. Synth. Commun. 1990, 1445.
(13) Wilgus, C. P.; Downing, S.; Molitor, E.; Bains, S.; Pagni, R. M.;
Kabalka, G. W. Tetrahedron Lett. 1995, 3469.
(14) Zil’berman, E. N. Russ. Chem. Rev. 1984, 53, 1548, and
references therein.
(15) (a) Ravindranathan, M.; Kalyanam, N.; Sivaram. S. J . Org.
Chem. 1982, 47, 4812. (b) Hayashi, H.; Nishi, H.; Watanebe, Y.;
Okazaki, T. J . Catal. 1981, 69, 44.
(16) J eong, H.; J oo, K.-S.; Chin, C. S. Bull. Korean Chem. Soc. 1997,
18, 402.
(17) (a) Patai, S. The Chemistry of Amidines and Imidates; J ohn
Wiley & Sons: London, 1978. (b) Maligres, P. E.; Upadhyay, W. V.;
Cianciosi, S. J .; Reamer, R. A.; Purick, R. M.; Sager, J .; Rossen, K.;
Eng, K. K.; Askin, D.; Volante, R. P.; Reider, P. J . Tetrahedron 1996,
52, 3327. (c) Lazarevski, G.; Vinkovic, M.; Kobrehel, G.; Dokic, S.
Tetrahedron 1994, 50, 12201. (d) Barbot, F. Tetrahedron Lett. 1989,
30, 185. (e) Pfau, M.; Felk, A.; Revial, G. Tetrahedron Lett. 1994, 35,
1549. (f) Nyilas, A. Tetrahedron Lett. 1997, 38, 2517. (g) Winter, H.;
Meada, Y.; Zemlica, J . J . Med. Chem. 1996, 39, 3300.
(18) (a) Matsuda, F. CHEMTECH 1977, 306. (b) Casey, J . M. Pulp
and Paper, 3rd ed.; Wiley-Intercience: New York, 1981; Vol. 2, p 1269,
Vol. 3, p 1449. (c) Chin, C. S.; Kim, S. Y.; J oo, K.-S.; Won, G.; Chong,
D. Bull. Korean Chem. Soc. 1999, 20, 535, and references therein.
Rea ction s of 1 w ith Ter tia r y Am in es (R3N) in
Ch lor in a ted Solven ts: Cp *Ir Cl(η3-CH2CHCHP h )
(3) a n d Qu a ter n a r y Am m on iu m Sa lts ([R3NX]OTf).
While no reaction has been observed between compound
1 and tertiary amines (NMe3, NEt3) in THF, compound
1 reacts with tertiary amines in chlorinated solvents to
give chlorine-substituted complex Cp*IrCl(η3-CH2CH-
(19) March, J . Advanced Organic Chemistry, 4th ed.; Wiley-Inter-
science: New York, 1992; p 21.

640 Organometallics, Vol. 19, No. 4, 2000
Chin et al.
CHPh) (3) and related quaternary ammonium salts [R3-
NX]OTf (R ) Me, Et and X ) CH2Cl, CHCl2, CH3, CCl3,
PhCH2) (eq 3).
F igu r e 2. ORTEP drawing of [Cp*Ir(η3-CH2CHCHPh)-
(NHdC(OMe)Me)]OTf (4a -Z) with 30% thermal ellipsoids
probability. Selected bond distances (Å): Ir1-N1 ) 2.094-
(5); Ir1-C6 ) 2.164(7); Ir1-C7 ) 2.150(9); Ir1-C8 ) 2.225-
Identification of 3 is straightforward by comparison
with the analogous spectral data for the (methylallyl)-
chloro complex Cp*IrCl(η3-CH2CHCHMe)20 previously
reported (see Experimental Section for spectral data).
Dichloromethane was known to act as an alkylating
agent toward NEt3.21 Sulfur alkylation was also re-
ported in the reactions of [PtS(PPh3)2]2 with CH2Cl2 (or
CHCl3) and of [PtCl2(PR3)2] with NaSH in CH2Cl2 to
produce [Pt2(-S)(-SR)(PPh3)4]+ (R ) CH2Cl, CHCl2)22
and [Pt(S2-CH2)(PR3)2],23 respectively. Other chlori-
nated solvents, CHCl3, CH3Cl, CCl4, and PhCH2Cl, are
also known to coordinate Cl- to transition metals.24
Coordination of CH2Cl2 to a transition metal is known
to occur through Cl.25 The C-Cl bond cleavage probably
occurs through the coordination of XCl via Cl atoms to
the metal followed by attack of the tertiary amine on
X.
(10); C6-C7 ) 1.42(2); C7-C8 ) 1.417(11); N1-C15
1.276(8); C15-O1 ) 1.300(12); O1-C17 ) 1.434(8); C15
C16 ) 1.500(12). Selected bond angles (deg): Ir1N1C15
)
-
)
130.5(6); N1C15C16 ) 121.0(9); N1C15O1 ) 116.8(7); C16C15
-
O1 ) 122.1(7); C15O1C17 ) 118.8(7); C6C7C8 ) 118.3(9).
Counteranion (OTf) and hydrogen atoms are omitted for
clarity.
The short bond distance of N(1)-C(15) (1.276(8) Å)
of 4a -Z shows a typical double-bond character (Figure
2). It is noticed that the C(15)-O(1) distance (1.300(12)
Å) is somewhat shorter than the average C(sp2)-O (1.34
Å),19 while it is much longer than C(sp2)dO (1.21 Å).19
It is also noticed that the angle C(15)-O(1)-C(17)
(118.8(7)°) is close to 120°. These observations may be
understood in terms of a resonance between the two
species, as shown in eq 5.
It should be mentioned here the amine-substituted
complexes [Cp*Ir(η3-CH2CHCHPh)(L)]+ (L ) H2NPh,
C5H5N) are obtained from the reactions of 1 with aniline
and pyridine in CHCl3 or benzene.
Ad d ition of Alcoh ols to MeCN in 1: Im in o-
E t h er Com p lex [Cp *Ir (η3-CH 2CH CH P h )(NH dC-
(OR)Me]OTf (4). Compound 1 also reacts with alcohols
under refluxing conditions to produce imino-ether
iridium(III) complexes 4a -c in the presence of Na2CO3
2-
(eq 4). The base CO3 seems to facilitate the cleavage
of the RO-H bond.
The imino-ether complexes 4a -c have been unam-
biguously characterized by spectral data (1H and 13C
NMR and IR) and by crystal structure determination
for 4a by X-ray diffraction data analysis (Experimental
Section and Figure 2). The crystal structure reveals the
OMe group being cis to the Ir.
The reaction of 1 with MeOH at room temperature
produces a mixture of 4a -Z (OMe group cis to Ir) and
4a -E (OMe group trans to Ir). As the crystal structure
of 4a -Z has been determined by X-ray diffraction data
1
(20) Gill, D. S.; White, C.; Maitlis, P. M. J . Chem. Soc., Dalton Trans.
1978, 617.
(21) Mas, M.; Sola, J .; Solans, X.; Aguilo, M. Inorg. Chim. Acta 1987,
133, 217.
(22) Yakathasan, G. R.; Morris, R. H.; Walker, A. Can. J . Chem.
1983, 61, 2490.
(23) Shaver, A.; Lai, R. D.; Bird, P. H.; Wickaramasinghe, W. Can.
J . Chem. 1985, 63, 2555.
(24) J ones, W. D.; Partridge, M. G.; Perutz, R. N. J . Chem. Soc.,
Chem. Commun. 1991, 264.
(25) (a) Arndtsen, B. A.; Bergman, R. G. Science 1995, 270, 1970.
(b) Cerotti, A.; Pergola, R. D.; Demartin, F. Garlaschelli, L.; Manassero,
M.; Masciocci, N. Organometallics 1992, 11, 756. (c) Agbossou, S. K.;
Fernandez, J . M.; Gladzy, J . A. Inorg. Chem. 1990, 29, 476. (d)
Svetlanova-Larsen, A.; Hubbard, J . L. Inorg. Chem. 1996, 35, 3073.
analysis (Figure 2), assignments of the H NMR signals
measured for the mixture of 4a -Z and 4a -E to each 4a -Z
and 4a -E are rather straightforward. Z and E isomers
of imino-ether metal complexes have been reported
with a suggested mechanism for the isomerization
between E and Z isomers.5a The isomer 4a -E slowly
undergoes isomerization to give 4a -Z in the presence
1
of MeOH and Na2CO3, which can be measured by H
NMR spectral changes (see Experimental Section). The
reaction of 1 with EtOH also produces both isomers
4b-E and -Z at room temperature, and 4b-E undergoes

Acetonitrile in [Cp*Ir(η3-CH2CHCHPh)(NCMe)]+
Organometallics, Vol. 19, No. 4, 2000 641
isomerization to give 4b-Z in the presence of EtOH and
Na2CO3. Only the Z isomer, 4c-Z, has been observed
from the reaction of 1 with i-PrOH and does not undergo
isomerization to give 4c-E even in the presence of
i-PrOH and Na2CO3.
To obtain more information on the reaction pathways
for the isomerization of 4-E to 4-Z, the ethanol adduct
(mixture of 4b-Z and -E) was stirred in MeOH solution
in the presence of Na2CO3 for 24 h at room temperature
to obtain 4a -Z in high purity. This observation suggests
that the isomerization is initiated by the attack of a
methoxy group on the imino carbon of 4b-E to give the
amido-ketal complex I, which then undergoes the
elimination of an ethoxy group to produce 4a -Z (eq 6).
The same type of mechanism has been suggested for
the isomerization of imino-ether Pt complexes.5a
F igu r e 3. ORTEP drawing of Cp*Ir(η3-CH2CHCHPh)-
(NHC(dO)Me) (5-K) with 50% thermal ellipsoids prob-
ability. Selected bond distances (Å): Ir-N ) 2.078(5);
Ir-C6 ) 2.219(6); Ir1-C7 ) 2.118(6); Ir1-C8 ) 2.153(6);
C6-C7 ) 1.422(9); C7-C8 ) 1.413(9); N-C9 ) 1.325(8);
C9-O ) 1.237(8); C9-C10 ) 1.505(10). Selected bond angles
(deg): IrNC9 ) 128.0(4); NC9C10 ) 117.5(7); NC9O ) 124.2-
(6); C10C9O ) 118.2(7); C6C7C8 ) 118.9(6).
longer than the average C(sp2)dO distance (1.21 Å),19
while C(9)-N (1.325(8) Å) is somewhat shorter than the
average C(sp2)-N (1.38 Å)19 but significantly longer
than the average C(sp2)dN (1.28 Å).19 These observa-
tions may be understood in terms of the resonance
structure, Ir-NHC(dO)Me T Ir-+NHdC(O-)Me.
The isomerization (4a -E to 4a -Z) does not occur in
the absence of MeOH and Na2CO3.
Rea ction of 1 w ith H2O in th e P r esen ce of
Na 2CO3: Am id o Com p lex Cp *Ir (η3-CH2CHCHP h )-
(NHC(dO)Me) (5-K). The MeCN of compound 1 is also
activated by H2O in the presence of Na2CO3 in refluxing
MeCN to produce the amido complex Cp*Ir(η3-CH2-
CHCHPh)(NHC(dO)Me) (5-K) with a significant amount
of acetamide (eq 7). The amido complex 5-K is also
obtained from the reactions of 1 with KOH or NaOH
solution of H2O/MeCN in the absence of Na2CO3.
The 1H NMR spectral measurements suggest two
isomers (5-K and 5-E) present in polar solvents such
as CDCl3 and CD2Cl2 (eq 8). Figure 4 clearly shows two
sets of signals in CDCl3 and CD2Cl2 and only one set of
signals in C6D6 and CD3COCD3. The signals in CD3-
COCD3 may be assigned to 5-E rather than 5-K taking
into account of the polarity of acetone.
There have been reports on the enol form of amide
(M-NHdC(OH)R) complexes,6b,c whereas no enol form
of the amido (M--NdC(OH)R) complex has been iden-
tified, although it has been suggested as the initial
products in the hydrolysis of coordinated nitriles.8e,9a
It may be conceivable to assign those signals (denoted
by a′ and b′) that are growing with increasing amount
of CDCl3 in Figure 5 to the enol form 5-E (see Experi-
mental Section).
Exactly the same spectrum in C6D6 (Figure 4 (i)) is
regenerated when the solvent is removed from the
solution of 5-E and 5-K in CDCl3, CD2Cl2, or CD3COCD3
and the resulting solid is redissolved in C6D6.
It should be mentioned here that infrared spectral
measurements both in Nujol and KBr suggest the keto
form complex 5-K being the dominant species in the
solid state. No differences have been found between the
spectra for all isolated solids from C6H6, CH3COCH3,
CHCl3, and CH2Cl2. The unusually low frequency (1600
cm-1) is observed for ν(CO) in 5-K with somewhat
The amido complex 5-K has been unequivocally
characterized by spectral and elemental analysis data
and also by crystal structure determination by X-ray
diffraction data analysis (Figure 3). Formation of 5-K
seems to be initiated by the attack of nucleophile -OH
on the nitrile carbon atom of 1 followed by a proton
transfer from the oxygen to the nitrogen atom. A similar
reaction mechanism has been proposed for the hydration
of the coordinated nitrile.11 It is well-established that
the base hydrolysis of coordinated nitriles produces a
keto form of amido complexes which have been identi-
fied by spectral6b-d,f,g,8a,b,e,11 and crystal structural data.4f
The amido moiety of 5-K in the solid state is best
described as the keto form, Ir-NHC(dO)Me, by a much
shorter distance of C(9)-O than that of C(9)-N. The
C(9)-O distance (1.237(8) Å) is much shorter than the
average C(sp2)-O distance (1.34 Å)19 but somewhat

642 Organometallics, Vol. 19, No. 4, 2000
Chin et al.
decrease significantly in intensity and a new absorption
band (ν(N-D)) appears at 2504 cm-1 in the infrared
spectrum of the deuterated amido complex 5-K-d 1
isolated from the C6D6/D2O solution.
Amido complex 5 reacts with HCl to give the chloro-
Cp*Ir(III) complex 3 and free acetamide, but no coor-
dinated acetamide complex has been observed. It is well-
established that amido complexes M-NHC(dO)R (M )
Pt,6c Co,6j Ru6h) are acidified to give amide complexes
M-NH2C(dO)R (M ) Pt,6b,c Ni,6a,i Pd6i). It is also known
that N-bonded amide complexes show a keto-enol
equilibrium between M-NH2C(dO)R and M-NHd
C(OH)R and also show linkage isomerization to O-
coordinated amide complexes M-OdC(NH2)R (M )
Co,11 Pt,6c Ru6h). Amide complexes are also obtained
from the direct reactions of metals and amides.6c
Syn th esis of th e En ol F or m of Am id e (Im in ol)
Com p lex [Cp *Ir (NHdC(OH)Me)(P P h 3)(OH2)](OTf)2
(6). In this study, attempts to prepare the acetamide
complex [Cp*Ir(η3-CH2CHCHPh)(NH2C(dO)Me)]+ have
been unsuccessful, while one acetamide complex 6 was
prepared from the reaction of Cp*IrCl2(PPh3)26 with
acetamide and AgOTf‚xH2O in CH2Cl2 (eq 9). The iminol
complex 6 has been characterized by spectral data and
also by crystal structure determination by X-ray dif-
fraction data analysis.
F igu r e 4. 1H NMR spectra of Cp*Ir(η3-CH2CHCHPh)-
(NHC(dO)Me) (5-K) and Cp*Ir(η3-CH2CHCHPh)(NdC(OH)-
Me) (5-E) in different deuterated solvents: (i) pure C6D6,
(ii) pure CD3COCD3, (iii) pure CD2Cl2, and (iv) pure CDCl3
at 300 MHz.
The binding mode of acetamide, that is, whether N-
or O-binding, was determined by the comparison of the
final R value, which is lower for the N-bonded form than
for the O-bonded one. The N-bonded Ir-NHdC(OH)-
Me moiety for 6 is also supported by a comparison
between the bond lengths Ir-N, C-N, and C-O of 6
and 4a -Z with Ir-NHdC(OMe)Me: bond lengths in Å,
Ir-N (2.048(16)), C-N (1.25(3)), and C-O (1.35(2)), of
6 are close to those (2.094(5), 1.276(8), and 1.300(12))
of 4a -Z.
The iminol moiety of 6 in the solid state is best
described by iminol ligand (Ir-NHdC(OH)Me) since the
distance of C(1)-N(1) is much shorter than the C(1)-
O(2) distance (Figure 6). The short bond length of C(1)-
N(1) (1.25(3) Å) is close to the average C(sp2)dN length
(1.28 Å)19 and much shorter than the average length of
C(sp2)-N (1.38 Å),19 while C(1)-O(2) (1.35(2) Å) is very
close to the average C(sp2)-O distance (1.34 Å)19 and
much longer than the average C(sp2)dO (1.21 Å).19
1H, 13C, and 31P NMR spectra of 6 show no evidence
for the other isomer of 6 in CDCl3. 1H NMR resonances
at 12.8 ppm (1H), 5.79 ppm (1H), and 1.88 ppm (3H)
are assigned to OH, NH, and Me of Ir-NHdC(OH)Me
(6), respectively. These observed chemical shifts in the
1H NMR spectrum of 6 are very close to those of the
well-known iminol complexes such as [dienPt(NHd
F igu r e 5. 1H NMR spectral change of Cp*Ir(η3-CH2-
CHCHPh)(NHC(dO)Me) (5-K) and Cp*Ir(η3-CH2CHCHPh)-
(NdC(OH)Me) (5-E) in different volume ratio of C6D6/
CDCl3 solution: (i) pure C6D6, (ii) C6D6/CDCl3 ) 8/2, (iii)
C6D6/CDCl3 ) 5/5, (iv) C6D6/ CDCl3 ) 2/8, and (v) pure
CDCl3 at 300 MHz.
higher frequency (1618 cm-1) for F(N-H), which is
confirmed by an H/D exchange experiment. It is seen
that the absorption bands at 1618 and 3374 (ν(N-H))
C(OH)Me)]2+ and [(NH3)5Co(NHdC(OH)Me)]3+ 6d,k
.
To the best of our knowledge, there have been only
two reports on the crystal structures of metal complexes
with N-bonded iminol.6a,b
(26) Glueck, D. S.; Winslow, L. J . N.; Bergman, R. G. Organome-
tallics 1991, 10, 1462, and references therein.

Acetonitrile in [Cp*Ir(η3-CH2CHCHPh)(NCMe)]+
Organometallics, Vol. 19, No. 4, 2000 643
is fairly rapid (MeC(dO)NH2/Ir/h ) 8.3 and total
conversion ) 4.1%) in the presence of 1 and Na2CO3,
while it is very slow in the absence of 1. Very small
amounts of MeC(dO)NH2 are obtained in the presence
of Na2CO3 (<0.01/h) and NaOH (0.4/h), respectively. The
hydration of crotononitrile (MeCHdCHCN) (eq 12) is
faster (MeCHdCHC(dO)NH2/Ir/h ) 13.3 and total
conversion ) 6.1%) than that of acetonitrile, while the
hydration of acrylonitrile (CH2dCHCN) is too slow
(CH2dCHC(dO)NH2/Ir/h < 0.1) to measure under the
same experimental conditions.
The hydration of benzonitrile is very slow (PhC(dO)-
NH2/Ir/h < 0.1) in the presence of the benzonitrile
complex [Cp*Ir(η3-CH2CHCHPh)(NCPh)]+ (11).28 On
the other hand, the methanolysis of benzonitrile pro-
ceeds rapidly (NHdC(OMe)Ph/Ir/h ) 6.2 and total
conversion ) 3.2%) to produce the imino-ether in the
presence of 11 and Na2CO3 (eq 13).
F igu r e 6. ORTEP drawing of [Cp*Ir(NHdC(OH)Me)-
(OH2)(PPh3)]OTf2 (6) with 30% thermal ellipsoids prob-
ability. Selected bond distances (Å): Ir1-N1 ) 2.048(16);
Ir1-P1 ) 2.332(5); Ir1-O1 ) 2.245(11); N1-C1 ) 1.25(3);
C1-O2 ) 1.35(2); C1-C2 ) 1.49(3). Selected bond angles
(deg): Ir1P1C14 ) 114.8(6); Ir1P1C8 ) 115.1(6); Ir1P1C20
113.9(6); P1Ir1O1 ) 87.7(4); O1Ir1N1 ) 78.4(5); Ir1N1C1
)
)
134.6(13); N1C1O2 ) 121.0(18); N1C1C2 ) 126(2). Two
counteranions (OTf) and hydrogen atoms are omitted for
clarity.
Dissocia tion of Am id in es a n d Im in o-Eth er s
fr om 2 a n d 4. Should amidines and imino-ethers in 2
and 4, respectively, be replaced by acetonitrile, one may
expect catalytic production of these organic compounds
from the reactions of acetonitrile with amines and
alcohols in the presence of 1. Amidines and imino-
ethers in 2 and 4 are not replaced by acetonitrile even
under refluxing conditions.
These two catalytic reactions (eqs 12 and 13) may be
represented by those cycles in Scheme 1 since the amido
complex 5 and imino-ether complex 4 have been
identified in the reactions of 1 with H2O and MeOH,
respectively.
Exp er im en ta l Section
Gen er a l In for m a tion . A standard vacuum system and
Schlenk type glassware were used in handling metal com-
plexes, although most of metal complexes investigated in this
study seemed to be stable enough to be handled without much
precautions against air and moisture.
They are, however, readily replaced with triphen-
ylphosphine (PPh3) (eqs 10 and 11). Imino-ethers are
known to undergo hydrolysis in the presence of acid and
water to give corresponding esters, while amidines are
relatively stable under similar conditions.27 Amidines
(8) and imino-ethers (9) have been unequivocally
The NMR spectra were obtained on a Varian Gemini 200,
300, or 500 MHz spectrometer for 1H and 50, 75, or 125 MHz
for 13C, and 121.3 MHz for 31P. Infrared spectra were obtained
on a Nicolet 205 or Shimadzu IR-440 spectrophotometer. Gas
chromatography/mass spectra were measured by Hewlett-
Packard HP 5890A and VG-trio 2000 instruments. Elemental
analysis was performed with a Carlo Erba EA1108 at the
Organic Chemistry Research Center, Sogang University,
Korea.
1
identified by H and 13C NMR measurements for the
reaction mixtures of 2 and 4 with PPh3, respectively,
in dried deuterated solvents (see Experimental Section).
[Cp*Ir(η3-CH2CHCHPh)(NCMe)]OTf (1)16 and Cp*IrCl2-
(PPh3)26 were prepared by the literature methods.
Syn th esis of [Cp *Ir (η3-CH2CHCHP h )(NH dC(NMe2)-
Me)]OTf (2a ). Meth od I. Compound 1 (0.10 g, 0.16 mmol)
was dissolved in CH2Cl2 (20 mL), and a 0.50 mL portion of a
50% aqueous solution of Me2NH was added drop by drop at
room temperature. The resulting mixture was refluxed for 6
h. The deep yellow solution was dehydrated by treatment of
MgSO4 and evaporated completely to remove the remaining
dimethylamine. The yellow residue was washed with cold Et2O
(10 mL) and recrystallized in CH2Cl2/Et2O to obtain pale yellow
microcrystals of [Cp*Ir(η3-CH2CHCHPh)(NHdC(NMe2)Me)]-
OTf (2a , 0.095 g, 87%).
Ca ta lytic Hyd r a tion a n d Meth a n olysis of Ni-
tr iles w ith [Cp *Ir (η3-CH2CHCHP h )(NCR)]OTf (R )
Me (1), MeCHdCH (10), P h (11)). The hydration of
acetonitrile is catalyzed by compound 1 at 70 °C to
produce acetamide (eq 12), which most likely proceeds
through the amido complex 5. The hydration of MeCN
Meth od II. Compound 1 (0.10 g, 0.16 mmol) in CH2Cl2 (10
mL) was added into a CH2Cl2 (10 mL) solution of Me2NH
(28) Complex 10 and 11 have been prepared from the reactions of 3
with the corresponding nitriles in the presence of AgOTf. See Experi-
mental Section for experimental details and spectral data.
(27) March, J . Advanced Organic Chemistry, 4th ed.; Wiley-Inter-
science: New York, 1992; p 892.

644 Organometallics, Vol. 19, No. 4, 2000
Chin et al.
Sch em e 1. P ossible Rea ction P a th w a ys for th e Ca ta lytic Hyd r a tion (R ) Me, MeCHdCH) a n d
Meth a n olysis (R ) P h ) of Nitr iles
(extracted from a 50% aqueous solution of Me2NH in water).
The mixture was refluxed in the presence of Na2CO3 for 3 h.
Syn th esis of [Cp*Ir (η3-CH2CHCHP h )(NHdC(NH(i-P r ))-
Me)]OTf (2c). Isopropylamine (0.035 mL, 0.41 mmol) was
added to a CH2Cl2 (20 mL) solution of 1 (0.10 g, 0.16 mmol),
and the reaction mixture was refluxed for 1.5 h. The reaction
mixture was cooled to room temperature and distilled under
vacuum to obtain a yellow residue, which was washed with
H2O (2.0 mL) and Et2O (10 mL) and recrystallized in CH2Cl2/
n-pentane to obtain beige-white microcrystals of [Cp*Ir(η3-CH2-
CHCHPh)(NHdC(NH(i-Pr))Me)]OTf (2c, 0.096 g, 86%). 1H
NMR (CDCl3, 25 °C): δ 1.23 and 1.31 (d, 6H, J (HH) ) 6.0 Hz,
NHdC(NHCH(CH3)2)Me), 1.64 (s, 15H, CH3 of Cp*), 2.46 (s,
3H, NHdC(NH(i-Pr))CH3), 3.31 (d, 1H, J (HH) ) 9.4 Hz,
CHHCHCHPh), 3.56 (m, 1H, NHCH(Me)2), 3.74 (m, 2H, CH2-
CHCHPh and CHHCHCHPh), 4.90 (m, 1H, CH2CHCHPh),
5.45 (br s, 1H, NH(i-Pr)), 7.48 (br s, 1H, NHdC), 7.12-7.37
(m, 5H, C6H5). 13C NMR (CDCl3, 25 °C): δ 8.14 and 92.8 (Cp*),
22.7 (NHdC(NH(i-Pr))CH3), 23.9 (NHCH(CH3)2), 43.0 (CH2-
CHCHPh), 45.3 (NHCH(Me)2), 63.9 (CH2CHCHPh), 77.0
(CH2CHCHPh), 126.4, 126.6, 128.7 and 138.4 (C6H5), 174.1
(NHdC). IR (Nujol, cm-1): 1621 (s, vCdN), 1030, 1163 and 1257
(br s, OTf). Anal. Calcd for C25H36O3N2SF3Ir: C, 43.28; H, 5.23;
N, 4.04. Found: C, 43.25; H, 5.09; N, 4.00.
Na2CO3 was removed on
a Celite-packed filter, and the
resulting yellow filtrate was distilled under vacuum to obtain
a beige solid, which was washed with H2O (5.0 mL) to remove
unreacted Me2NH. The beige solid was recrystallized in CH2-
Cl2/Et2O to obtain pale yellow microcrystals of 2a (0.10 g, 93%).
1H NMR (CDCl3, 25 °C): δ 1.42 (s, 15H, CH3 of Cp*), 1.72 (d,
1H, J (HH) ) 9.4 Hz, CHHCHCHPh), 2.07 (s, 3H, NHd
C(NMe2)CH3), 2.93 (s, 6H, NHdC(N(CH3)2)Me), 3.20 (d, 1H,
J (HH) ) 6.0 Hz, CHHCHCHPh), 3.26 (d, 1H, J (HH) ) 9.0 Hz,
CH2CHCHPh), 4.89 (m, 1H, CH2CHCHPh), 5.42 (br s, 1H,
NHdC), 6.90-7.17 (m, 5H, C6H5). 13C NMR (CDCl3, 25 °C): δ
8.0 and 93.0 (Cp*), 22.1 (NHdC(NMe2)CH3), 39.1 and 40.1
(NHdC(N(CH3)2)Me), 44.4 (CH2CHCHPh), 63.1 (CH2CHCHPh),
77.7 (CH2CHCHPh), 125.9, 126.3, 129.1 and 139.0 (C6H5),
167.3 (NHdC). IR (Nujol, cm-1): 1590 (s, vCdN), 1032, 1146
and 1271 (br s, OTf). Anal. Calcd for C24H34O3N2SF3Ir: C,
42.40; H, 5.04; N, 4.12. Found: C, 42.35; H, 4.90; N, 4.11.
Syn th esis of [Cp *Ir (η3-CH2CHCHP h )(NH dC(NHMe)-
Me)]OTf (2b). Meth od I. A 0.50 mL portion of 40% aqueous
solution of MeNH2 was added into a CH2Cl2 solution of 1 (0.10
g, 0.16 mmol) at room temperature in a bomb reactor (Parr
1341, 360 mL), which was placed on an oil bath maintained
at 50 °C for 12 h with stirring. The pale yellow microcrystals
of [Cp*Ir(η3-CH2CHCHPh)(NHdC(NHMe)Me)]OTf (2b, 0.082
g, 77%) were obtained after treatment of the reaction mixture
in the same manner as described for 2a above.
Syn t h esis of [Cp *Ir (η3-CH 2CH CH P h )(NH dC(NCH 2-
(CH2)3CH2)Me)]OTf (2d ). This compound was prepared in
the same manner as described for the reaction of 2c using 1
(0.10 g, 0.16 mmol) and piperidine (0.035 g, 0.41 mmol). Beige-
white microcrystals of [Cp*Ir(η3-CH2CHCHPh)(NHdC(NCH2-
(CH2)3CH2)Me)]OTf (2d , 0.11 g, 97%) were obtained. 1H NMR
(CDCl3, 25 °C): δ 1.62 (s, 15H, CH3 of Cp*), 2.05 (d, 1H,
Meth od II. To 0.10 g (0.16 mmol) of 1 in CH2Cl2 (10 mL)
was added a CH2Cl2 (10 mL) solution of MeNH2 (extracted
from a 40% aqueous solution of MeNH2 in water). The mixture
was refluxed for 12 h before a 10 mL portion of water was
added to the reaction mixture. Excess MeNH2 in the aqueous
layer was separated from 2b in the CH2Cl2 layer, which was
concentrated to 2.0 mL. Addition of Et2O (20 mL) to the CH2-
Cl2 solution resulted in precipitation of pale yellow microcrys-
tals of [Cp*Ir(η3-CH2CHCHPh)(NHdC(NHMe)Me)]OTf (2b,
0.096 g, 90%). 1H NMR (CDCl3, 25 °C): δ 1.60 (s, 15H, CH3 of
Cp*), 1.88 (d, 1H, J (HH) ) 9.4 Hz, CHHCHCHPh), 2.43 (s,
3H, NHdC(NHMe)CH3), 3.06 (s, 3H, NHCH3), 3.45 (d, 1H,
J (HH) ) 6.0 Hz, CHHCHCHPh), 3.49 (d, 1H, J (HH) ) 9.0 Hz,
CH2CHCHPh), 4.96 (m, 1H, CH2CHCHPh), 5.58 (br s, 1H,
NHMe), 7.25 (br s, 1H, NHdC), 7.33-7.64 (m, 5H, C6H5). 13C
NMR (CDCl3, 25 °C): δ 8.34 and 93.2 (Cp*), 19.2 (NHd
C(NHMe)CH3), 30.4 (CH2CHCHPh), 40.9 (NHdC(NHCH3)Me),
63.4 (CH2CHCHPh), 75.9 (CH2CHCHPh), 126.1, 126.4, 129.0
and 138.8 (C6H5), 168.2 (NHdC). IR (Nujol, cm-1): 1624 (br
s, vCdN), 1032, 1146 and 1271 (br s, OTf). Anal. Calcd for
J (HH) ) 10.0 Hz, CHHCHCHPh), 2.33 (s, 3H, NHdC(NCH2-
(CH2)3CH2)CH3), 3.41 (d, 1H, J (HH) ) 7.0 Hz, CHHCHCHPh),
3.62 and 1.67 (m, 10H, NHdC(NCH2(CH2)3CH2)Me), 3.71 (d,
1H, J (HH) ) 9.8 Hz, CH2CHCHPh), 5.1 (m, 1H, CH2CHCHPh),
6.07 (br s, 1H, NHdC), 7.1-7.3 (m, 5H, C6H5). 13C NMR
(CDCl3, 25 °C): δ 8.29 and 93.0 (Cp*), 22.7, 23.7 and 47.8
(NHdC(NCH2(CH2)3CH2)Me), 25.6 (NHdC(NCH2(CH2)3CH2)-
CH3), 45.0 (CH2CHCHPh), 63.1 (CH2CHCHPh), 77.8 (CH2-
CHCHPh), 125.9, 126.1, 129.0 and 138.8 (C6H5), 166.6 (NHd
C). IR (Nujol, cm-1): 1605 (s, vCdN), 1028, 1125 and 1250 (br
s, OTf). Anal. Calcd for C27H38O3N2SF3Ir: C, 45.05; H, 5.32;
N, 3.89. Found: C, 45.01; H, 5.28; N, 3.88.
Rea ction of 1 w ith NEt3 in CH2Cl2. A 10 mL portion of
NEt3 was added to a CH2Cl2 solution of 1 (0.10 g, 0.16 mmol),
and the reaction mixture was refluxed for 2.5 h, during which
time the reaction mixture turned more yellowish. After
solvents and excess reacted Et3N were removed by vacuum
distillation, n-pentane (20 mL) was added to dissolve 3 (Cp*Ir-
C
23H32O3N2SF3Ir: C, 41.49; H, 4.84; N, 4.21. Found: C, 41.48;
H, 4.74; N, 4.17.

Acetonitrile in [Cp*Ir(η3-CH2CHCHPh)(NCMe)]+
Organometallics, Vol. 19, No. 4, 2000 645
(η3-CH2CHCHPh)Cl), and the reaction mixture was filtered to
separate the insoluble white ammonium salt, [Et3NCH2Cl]OTf.
The filtrate was distilled under vacuum to obtain a yellow
solid, which was recrystallized in n-pentane/MeOH at -20 °C
to obtain yellow microcrystals of Cp*IrCl(η3-CH2CHCHPh) (3,
0.073 g, 95%). 1H NMR (CDCl3, 25 °C): δ 1.51 (s, 15H, CH3 of
Cp*), 2.74 (d, 1H, J (HH) ) 10.0 Hz, CHHCHCHPh), 3.30 (d,
1H, J (HH) ) 6.0 Hz, CHHCHCHPh), 4.50 (d, 1H, J (HH) )
10.0 Hz, CH2CHCHPh), 5.04 (m, 1H, CH2CHCHPh), 7.14-
7.33 (m, 5H, C6H5). 13C NMR (CDCl3, 25 °C): δ 8.6 and 92.6
(Cp*), 44.3 (CH2CHCHPh), 64.6 (CH2CHCHPh), 77.2 (CH2CH-
CHPh), 125.8, 126.1, 129 and 141.0 (C6H5). Anal. Calcd for
25 °C): δ 1.51 (s, 15H, CH3 of Cp*), 2.07 (d, 1H, J (HH) ) 10.0
Hz, CHHCHCHPh), 2.62 (s, 3H, NHdC(OMe)CH3), 3.38 (d,
1H, J (HH) ) 6.0 Hz, CHHCHCHPh), 3.65 (d, 1H, J (HH) )
10.0 Hz, CH2CHCHPh), 4.01 (s, 3H, OCH3), 4.87 (m, 1H,
CH2CHCHPh), 7.15-7.33 (m, 5H, C6H5), 9.35 (br s, 1H, NH).
13C NMR (CDCl3, 25 °C): δ 8.03 and 92.6 (Cp*), 19.1 (NHd
C(OMe)CH3), 42.5 (CH2CHCHPh), 57.1 (OCH3), 62.0 (CH2-
CHCHPh), 76.0 (CH2CHCHPh), 126.2, 126.5, 128.7 and 139.5
(C6H5), 177.6 (NHdC). IR (KBr, cm-1): 1629 (s, vCdN), 1027,
1143 and 1254 (br s, OTf). Anal. Calcd for C23H31O4NSF3Ir:
C, 41.43; H, 4.69; N, 2.10. Found: C, 41.42; H, 4.66; N, 2.00.
Syn th esis of[Cp *Ir (η3-CH2CHCHP h )(NHdC(OMe)Me)]-
OTf (m ixtu r e of 4a -Z/4a -E) a n d Isom er iza tion of 4a -E to
4a -Z. A methanol (20 mL) solution of 1 (0.10 g, 0.16 mmol)
was stirred in the presence of Na2CO3 (0.055 g, 0.52 mmol) at
room temperature for 6 h. Na2CO3 was removed on a Celite-
packed filter, and the resulting filtrate was distilled under
vacuum to obtain a beige solid, which was recrystallized in
cold CHCl3/Et2O to obtain beige-white microcrystals of [Cp*Ir-
(η3-CH2CHCHPh)(NHdC(OMe)Me)]OTf (0.097 g, 91%, 4a -
Z/E ) 4/1 measured by 1H NMR). Data for 4a -E are as follows.
1H NMR (CDCl3, 25 °C): δ 1.55 (s, 15H, CH3 of Cp*), 2.07 (d,
1H, J (HH) ) 10.0 Hz, CHHCHCHPh), 2.32 (s, 3H, CH3), 3.27
(d, 1H, J (HH) ) 6.0 Hz, CHHCHCHPh), 3.64 (d, 1H, J (HH) )
10.0 Hz, CH2CHCHPh), 4.02 (s, 3H, OCH3), 5.03 (m, 1H,
CH2CHCHPh), 7.15-7.33 (m, 5H, C6H5), 8.37 (br s, 1H, NHd
C). The 4a -E was converted to 4a -Z when the mixture was
refluxed for 6 h or stirred for 24 h at room temperature in
MeOH solution in the presence of Na2CO3. The isomerization
(4a -E to 4a -Z) was not observed under refluxing conditions in
CHCl3 for 6 h in the absence of MeOH and/or Na2CO3.
Syn th esis of [Cp *Ir (η3-CH2CHCHP h )(NHdC(OEt)Me)]-
OTf (4b-Z). This compound was prepared by the same method
as described above for the synthesis of 4a -Z using 0.10 g of 1
in ethanol. The yield was 0.10 g (91%) based on [Cp*Ir(η3-CH2-
CHCHPh)(NHdC(OEt)Me)]OTf (4b-Z). 1H NMR (CDCl3, 25
°C): δ 1.45 (t, 3H, J (HH) ) 10.0 Hz, OCH2CH3), 1.52 (s, 15H,
CH3 of Cp*), 2.04 (d, 1H, J (HH) ) 10.0 Hz, CHHCHCHPh),
2.62 (s, 3H, NHdC(OEt)CH3), 3.36 (d, 1H, J (HH) ) 6.0 Hz,
CHHCHCHPh), 3.66 (d, 1H, J (HH) ) 10.0 Hz, CH2CHCHPh),
4.27 (q, 2H, J (HH) ) 10.0 Hz, OCH2CH3), 4.88 (m, 1H,
CH2CHCHPh), 7.15-7.50 (m, 5H, C6H5), 9.13 (br s, 1H, NHd
C). 13C NMR (CDCl3, 25 °C): δ 8.06 and 92.6 (Cp*), 14.8
(OCH2CH3), 19.7 (NHdC(OEt)CH3), 42.4 (CH2CHCHPh), 62.2
(OCH2CH3), 66.4 (CH2CHCHPh), 75.9 (CH2CHCHPh), 126.1,
126.5, 126.7 and 139.4 (C6H5), 177.3 (NHdC). IR (Nujol, cm-1):
1641 (s, vCdN), 1030, 1163 and 1257 (br s, OTf). Anal. Calcd
for C24H33O4NSF3Ir: C, 42.34; H, 4.89; N, 2.06. Found: C,
42.33; H, 4.85; N, 2.04.
C
19H24ClIr: C, 47.54; H, 5.04. Found: C, 47.52; H, 5.00.
Data for [Et3NCH2Cl]OTf (0.048 g, 95%) are as follows. H
1
NMR (D2O, 25 °C): δ 1.36 (t, 9H, J (HH) ) 7.3 Hz, CH2CH3),
3.38 (q, 6H, J (HH) ) 7.3 Hz, CH2CH3), 5.09 (s, 2H, CH2Cl).
13C NMR (D2O, 25 °C): δ 6.46 (CH2CH3), 52.3 (CH2CH3), 62.2
(CH2Cl). IR (KBr, cm-1): 1032, 1165 and 1249 (br s, OTf).
All Oth er Rea ction s of 1 w ith NR3 (R ) Me, Et) in
CHCl3, CH2Cl2, MeCl, P h CH 2Cl, a n d CCl4. These reactions
were carried out in the same manner described above for the
reaction of 1 with NEt3 in CH2Cl2. Yields of [R3NX]OTf and
their spectral data are summarized below.
Data for [Me3NCH2Cl]OTf (95%) are as follows. 1H NMR
(CD3CN, 25 °C): δ 3.28 (s, 9H, N(CH3)3), 5.44 (s, 2H, CH2).
13C NMR (CD3CN, 25 °C): δ 51.5 (CH3), 70.6 (CH2). IR (KBr,
cm-1): 1024, 1138 and 1247 (br s, OTf).
1
Data for [Et3NMe]OTf (95%) are as follows. H NMR (D2O,
25 °C): δ 1.31 (t, 9H, J (HH) ) 7.4 Hz, CH2CH3), 3.33 (q, 6H,
J (HH) ) 7.4 Hz, CH2CH3), 2.94 (s, 3H, NCH3). 13C NMR (D2O,
25 °C): δ 6.7 (CH2CH3), 55.6 (CH2CH3), 46.2 (NCH3). IR (KBr,
cm-1): 1024, 1140 and 1256 (br s, OTf).
1
Data for [Me4N]OTf (96.5%) are as follows. H NMR (D2O,
25 °C): δ 3.17 (s, 12H, CH3). 13C NMR (D2O, 25 °C): δ 55.1
(CH3). IR (KBr, cm-1): 1028, 1148 and 1252 (br s, OTf).
Data for [Et3NCHCl2]OTf (95%) are as follows. 1H NMR
(D2O, 25 °C): δ 1.28 (t, 9H, J (HH) ) 7.3 Hz, CH2CH3), 3.21
(q, 6H, J (HH) ) 7.3 Hz, CH2CH3), 7.58 (s, 1H, CHCl2). 13C
NMR (D2O, 25 °C): δ 8.04 (CH2CH3), 46.6 (CH2CH3), 57.4
(CHCl2). IR (KBr, cm-1): 1026, 1155 and 1242 (br s, OTf).
Data for [Me3NCHCl2]OTf (90%) are as follows. 1H NMR
(D2O, 25 °C): δ 3.14 (s, 9H, CH3), 7.78 (s, 1H, CHCl2). 13C NMR
(D2O, 25 °C): δ 47.58 (CH3), 58.0 (CHCl2). IR (KBr, cm-1):
1026, 1140 and 1248 (br s, OTf).
Data for [Et3NCH2Ph]OTf (98%) are as follows. 1H NMR
(D2O, 25 °C): δ 1.28 (t, 9H, J (HH) ) 7.3 Hz, CH2CH3), 3.24
(q, 6H, J (HH) ) 7.3 Hz, CH2CH3), 4.42 (s, 2H, CH2Ph), 7.55
(br s, 5H, C6H5). 13C NMR (D2O, 25 °C): δ 6.77 (CH2CH3), 52.1
(CH2CH3), 59.77 (CH2Ph), 127.36, 129.5, 130.8 and 132.6
(C6H5). IR (KBr, cm-1): 1000, 1146 and 1208 (br s, OTf).
Data for [Me3NCH2Ph]OTf (97%) are as follows. 1H NMR
(D2O, 25 °C): δ 3.06 (s, 9H, CH3), 4.46 (s, 2H, CH2Ph), 7.53
(br s, 5H, C6H5). 13C NMR (D2O, 25 °C): δ 52.7 (CH3), 68.9
(CH2Ph), 133.1, 130.7, 129.1 and 127.8 (C6H5). IR (KBr, cm-1):
1026, 1146 and 1247 (br s, OTf).
Data for [Et3NCCl3]OTf (95%) are as follows. 1H NMR (D2O,
25 °C): δ 1.27 (t, 9H, J (HH) ) 7.4 Hz, CH2CH3), 3.19 (q, 6H,
J (HH) ) 7.4 Hz, CH2CH3). 13C NMR (D2O, 25 °C): δ 8.63
(CH2CH3), 46.0 (CH2CH3). IR (KBr, cm-1): 1022, 1159 and
1231 (br s, OTf).
Data for [Me3NCCl3]OTf (98%) are as follows. 1H NMR (D2O,
25 °C): δ 2.87(s, 9H, CH3). 13C NMR (D2O, 25 °C): δ 44.68
(CH3). IR (KBr, cm-1): 1025, 1149 and 1248 (br s, OTf).
Syn th esis of[Cp *Ir (η3-CH2CHCHP h )(NHdC(OMe)Me)]-
OTf (4a -Z). A methanol (20 mL) solution of 1 (0.10 g, 0.16
mmol) was refluxed in the presence of Na2CO3 (0.055 g, 0.52
mmol) for 6 h. Na2CO3 was removed on a Celite-packed filter,
and the resulting filtrate was distilled under vacuum to obtain
a beige solid, which was recrystallized in cold CHCl3/Et2O to
obtain beige-white microcrystals of [Cp*Ir(η3-CH2CHCHPh)-
(NHdC(OMe)Me)]OTf (4a -Z, 0.095 g, 89%).1H NMR (CDCl3,
Syn th esis of [Cp *Ir (η3-CH2CHCHP h )(NHdC(OEt)Me)]-
OTf (m ixtu r e of 4b-Z/4b-E). This compound was prepared
by the same method as described above for the synthesis of
the mixture of 4a -Z/E using 0.10 g of 1 in ethanol. The yield
was 0.097 g (89%) based on [Cp*Ir(η3-CH2CHCHPh)(NHd
C(OEt)Me)]OTf (4b-Z/E ) 5/1). Data for 4b-E are as follows.
1H NMR (CDCl3, 25 °C): δ 1.36 (t, 3H, J (HH) ) 10.0 Hz,
OCH2CH3), 1.55 (s, 15H, CH3 of Cp*), 2.09 (d, 1H, J (HH) )
10.0 Hz, CHHCHCHPh), 2.31 (s, 3H, NHdC(OEt)CH3), 3.03
(d, 1H, J (HH) ) 6.0 Hz, CHHCHCHPh), 3.55 (d, 1H, J (HH) )
10.0 Hz, CH2CHCHPh), 4.31 (q, 2H, J (HH) ) 10.0 Hz, OCH2-
CH3), 5.07 (m, 1H, CH2CHCHPh), 7.15-7.50 (m, 5H, C6H5),
8.16 (br s, 1H, NHdC). The 4b-E was converted to 4b-Z when
the mixture was refluxed for 6 h or stirred for 24 h at room
temperature in EtOH solution in the presence of Na2CO3. The
isomerization (4b-E to 4b-Z) was not observed under refluxing
conditions in CHCl3 for 6 h in the absence of EtOH and/or Na2-
CO3.
Isom er iza tion a n d Su bstitu tion of 4b-Z/E for 4a -Z. The
mixture of 4b-Z/E (0.088 g, 0.13 mmol) was stirred for 24 h at
room temperature in MeOH (20 mL) solution in the presence
of Na2CO3 (0.051 g, 0.52 mmol). Excess Na2CO3 was removed

646 Organometallics, Vol. 19, No. 4, 2000
Chin et al.
by filtration on a Celite-packed filter, and the resulting filtrate
was distilled under vacuum to obtain a beige solid. The 1H
NMR spectrum of this beige solid shows only the signals due
to 4a -Z.
J (HH) ) 10.0 Hz, CHHCHCHPh), 1.92 (s, 3H, NdC(OH)CH3),
3.23 (d, 1H, J (HH) ) 6.0 Hz, CHHCHCHPh), 3.55 (d, 1H,
J (HH) ) 10.0 Hz, CH2CHCHPh), 4.13 (br s, NdC(OH)Me),
5.04 (m, 1H, CH2CHCHPh), 7.20-7.60 (m, 5H, C6H5). 13C NMR
(CD3COCD3, 25 °C): δ 9.08 and 92.9 (Cp*), 27.0 (NdC(OH)-
CH3),41.3(CH2CHCHPh),62.1(CH2CHCHPh),74.2(CH2CHCHPh),
125.8, 128.6, 129.0 and 142.9 (C6H5), 173.6 (NdC(OH)CH3).
13C NMR (CDCl3, 25 °C): δ 8.08 and 91.8 (Cp*), 26.8 (Nd
C(OH)CH3), 40.5 (CH2CHCHPh), 61.1 (CH2CHCHPh), 73.3
(CH2CHCHPh), 125.1, 125.7, 128.2 and 141.3 (C6H5), 175.0
(NdC(OH)Me).
Syn th esis of [Cp *Ir (η3-CH2CHCHP h )(NHdC(O-i-P r )-
Me)]OTf (4c-Z). This compound was prepared in the same
manner as described above for the synthesis of 4a using 0.10
g of 1 in 2-propanol. The yield was 0.10 g (90%) based on
[Cp*Ir(η3-CH2CHCHPh)(NHdC(O-i-Pr)Me)]OTf (4c-Z). 1H NMR
(CDCl3, 25 °C): δ 1.29 and 1.39 (d, 6H, J (HH) ) 6.0 Hz, OCH-
(CH3)2), 1.54 (s, 15H, CH3 of Cp*), 1.93 (d, 1H, J (HH) ) 9.0
Hz, CHHCHCHPh), 2.64 (s, 3H, NHdCCH3), 3.36 (d, 1H,
J (HH) ) 5.0 Hz, CHHCHCHPh), 3.43 (d, 1H, J (HH) ) 10.0
Hz, CH2CHCHPh), 4.71 (m, 1H, OCH(Me)2), 4.83 (m, 1H,
CH2CHCHPh), 7.23-7.38 (m, 5H, C6H5), 9.26 (br s, 1H, NH).
13C NMR (CDCl3, 25 °C): δ 8.01 and 92.6 (Cp*), 19.6 (NHd
CCH3), 22.7 (OCH(CH3)2), 41.9 (CH2CHCHPh), 62.2 (CH2-
CHCHPh), 74.2 (OCHMe2), 75.8 (CH2CHCHPh), 126.8, 127,
128.6 and 139.4 (C6H5), 176.4 (NHdC). IR (KBr, cm-1): 1629
(s, vCdN), 1024, 1146 and 1252 (br s, OTf). Anal. Calcd for
Syn th esis of Cp *Ir (η3-CH2CHCHP h )(NDC(dO)Me) (5-
K-d 1): H/D Exch a n ge Rea ction of 5-K in D2O. A 0.05 mL
portion of D2O was added to a yellow C6D6 (0.50 mL) solution
of 5-K (0.056 mmol) in an absolutely dried NMR tube, which
was maintained at room temperature for 5 h. The deuterated
amido complex 5-K-d 1 was isolated by vacuum distillation of
all solvents. The complex 5-K-d 1 was characterized by com-
1
parison of its H NMR and IR spectral data to those assigned
by 5-K. The 1H NMR resonance at δ 3.51 (Ir-NHC(dO)Me)
and IR absorption band at 3374 cm-1 (ν(N-H)) of 5-K were
decreased in intensity (ca. 50%), and a new absorption band
(v(N-D)) appeared at 2504 cm-1 in the infrared spectrum of
5-K-d 1. IR (KBr, cm-1): 2504 (w, νN-D).
C
25H35O4NSF3Ir: C, 43.22; H, 5.08; N, 2.01. Found: C, 42.45;
H, 4.77; N, 1.89.
Syn th esis of Cp *Ir (η3-CH2CHCHP h )(NHC(dO)Me) (5-
K) a n d Ch a r a cter iza tion of Cp *Ir (η3-CH2CHCHP h )(Nd
C(OH)Me) (5-E) in P ola r Solven ts. A 0.5 mL portion of
distilled water and 0.5 g (4.7 mmol) of Na2CO3 were added to
MeCN (10 mL) solution of 1 (0.20 g, 0.32 mmol) under N2, and
the solution was refluxed for 3 h and cooled to room temper-
ature. Na2CO3 was removed on a Celite-packed filter, and the
resulting filtrate was distilled under vacuum to obtain yellow
powders, which were recrystallized in cold CH2Cl2/n-pentane
to obtain yellow microcrystals of Cp*Ir(η3-CH2CHCHPh)(NHC-
Rea ction of 5 w ith HCl. HCl (0.21 mmol, 0.20 mL of a 32
wt % solution in H2O) was added to a solution of 5 (0.10 g,
0.20 mmol) in CHCl3 (15 mL) at room temperature, and the
reaction mixture was stirred for 3 h. After the yellow solution
was dehydrated by treatment with MgSO4 and vacuum
distilled to remove the solvents and unreacted HCl, n-pentane
(20 mL) was added to dissolved chloro-metal complex 3, and
the reaction mixture was filtered to obtain less soluble MeC-
1
1
(dO)NH2, which was identified by H NMR spectroscopy and
(dO)Me) (5-K, 0.15 g, 93%). H NMR (C6D6, 25 °C): δ 1.43 (s,
also by GC.
15H, CH3 of Cp*), 1.75 (d, 1H, J (HH) ) 10.0 Hz, CHHCH-
CHPh), 2.21 (s, 3H, NHC(dO)CH3), 3.11 (d, 1H, J (HH) ) 6.0
Hz, CHHCHCHPh), 3.51 (br s, NHC(dO)Me), 4.15 (d, 1H,
J (HH) ) 10.0 Hz, CH2CHCHPh), 4.73 (m, 1H, CH2CHCHPh),
Syn th esis of [Cp *Ir (NHdC(OH)Me)(P P h 3)(OH2)](OTf)2
(6). A 0.015 g (0.25 mmol) sample of acetamide and 0.13 g
(ca. 0.50 mmol) of AgOTf‚xH2O were added to a 10 mL CH2-
Cl2 solution of Cp*IrCl2(PPh3) (0.15 g, 0.23 mmol), and the
reaction mixture was stirred at room temperature for 1 h. AgCl
was removed by filtration, and the filtrate was vacuum
distilled to obtain a yellow solid, which was recrystallized in
CH2Cl2/Et2O to obtain yellow microcrystals of [Cp*Ir(NHd
C(OH)Me)(PPh3)(OH2)](OTf)2 (6, 0.21 g, 95%). 1H NMR (CDCl3,
25 °C): δ 1.49 (s, 15H, CH3 of Cp*), 1.88 (s, 3H, NHdC(OH)-
CH3), 5.79 (br s, 1H, NHdC(OH)Me), 7.2-7.6 (m, 15H,
P(C6H5)3), 12.8 (br s, 1H, NHdC(OH)Me). 31P NMR (CDCl3,
25 °C): δ 19.6 (PPh3). 13C NMR (CDCl3, 25 °C): δ 9.4 and 94.0
(Cp*), 22.1 (NHdC(OH)CH3), 129.0, 131.8, 134.5 and 141.9
(P(C6H5)3), 175.8 (NHdC(OH)Me). IR (KBr, cm-1): 1669.7 (m,
1
7.25-7.87 (m, 5H, C6H5). H NMR (CDCl3, 25 °C): δ 1.51 (s,
15H, CH3 of Cp*), 1.68 (d, 1H, J (HH) ) 10.0 Hz, CHHCH-
CHPh), 2.01 (s, 3H, NHC(dO)CH3), 3.15 (d, 1H, J (HH) ) 6.0
Hz, CHHCHCHPh), 3.79 (br s, 1H, NHC(dO)Me), 3.81 (d, 1H,
J (HH) ) 10.0 Hz, CH2CHCHPh), 4.80 (m, 1H, CH2CHCHPh),
1
7.05-7.60 (m, 5H, C6H5). H NMR (CD2Cl2, 25 °C): δ 1.50 (s,
15H, CH3 of Cp*), 1.67 (d, 1H, J (HH) ) 10.0 Hz, CHHCH-
CHPh), 2.00 (s, 3H, NHC(dO)CH3), 3.14 (d, 1H, J (HH) ) 6.0
Hz, CHHCHCHPh), 3.70 (d, 1H, J (HH) ) 10.0 Hz, CH2-
CHCHPh), 3.75 (br s, 1H, NHC(dO)Me), 4.83 (m, 1H,
CH2CHCHPh), 7.05-7.60 (m, 5H, C6H5). 13C NMR (C6D6, 25
°C): δ 8.98 and 92.4 (Cp*), 27.5 (CH3), 41.2 (CH2CHCHPh),
63.0 (CH2CHCHPh), 74.0 (CH2CHCHPh), 174.5 (NHC(dO)-
Me). 13C NMR (CDCl3, 25 °C): δ 8.02 and 92.4 (Cp*), 29.5
(CH3), 43.7 (CH2CHCHPh), 64.1 (CH2CHCHPh), 76.8 (CH2-
CHCHPh), 125.5, 125.8, 127.2 and 140.4 (C6H5), 179.1 (NHC(d
O)Me). IR (KBr, cm-1): 1600 (s, νCdO), 3374 (w, νN-H), 1618 (s,
νCdN), 1035, 1179 and 1266 (br s, OTf). Anal. Calcd for
C32H37O8NPS2F6Ir: C, 39.10; H, 3.79; N, 1.43. Found: C, 39.06;
H, 3.78; N, 1.35.
Dissocia tion of Im in o-Eth er s a n d Am id in es fr om
Ir id iu m (III) Com p ou n d s: Rea ction of 2a w ith P P h 3. A
0.041 g (0.16 mmol) of PPh3 was added to a THF-d8 (1.0 mL)
(or CD2Cl2) solution of 2a (0.052 mmol), and the reaction
mixture was refluxed for 12 h and cooled to room temperature.
Both THF-d8 and NHdC(NMe2)Me (8a ) were collected in the
cold trap of a dry ice/i-PrOH bath, and the residue was washed
with Et2O (10 mL) to obtain [Cp*Ir(η3-CH2CHCHPh)(PPh3)]-
OTf (7) in high yield (90%, 0.040 g).
FN-H). Anal. Calcd for C21H28ONIr: C, 50.18; H, 5.61; N, 2.79.
Found: C, 50.21; H, 5.59; N, 2.75. The enol form of the amido
complex Cp*Ir(η3-CH2CHCHPh)(NdC(OH)Me) (5-E) was mea-
sured by 1H and 13C NMR in polar solvents such as CD3COCD3
(5-E), CDCl3 (5-E/K ) ca. 1:2), and CD2Cl2 (5-E/K ) ca. 1:3)
1
(see Figure 4). Spectral data for 5-E are as follows. H NMR
(CD3COCD3, 25 °C): δ 1.52 (s, 15H, CH3 of Cp*), 1.67 (d, 1H,
J (HH) ) 9.2 Hz, CHHCHCHPh), 1.93 (s, 3H, NdC(OH)CH3),
3.11 (d, 1H, J (HH) ) 6.2 Hz, CHHCHCHPh), 3.72 (d, 1H,
J (HH) ) 9.6 Hz, CH2CHCHPh), 4.00 (br s, NdC(OH)Me), 5.00
(m, 1H, CH2CHCHPh), 7.25-7.72 (m, 5H, C6H5). 1H NMR
(CDCl3, 25 °C): δ 1.51 (s, 15H, CH3 of Cp*), 1.95 (d, 1H,
J (HH) ) 10.0 Hz, CHHCHCHPh), 2.00 (s, 3H, NdC(OH)CH3),
3.21 (d, 1H, J (HH) ) 6.0 Hz, CHHCHCHPh), 3.60 (d, 1H,
J (HH) ) 10.0 Hz, CH2CHCHPh), 4.34 (br s, NdC(OH)Me),
5.00 (m, 1H, CH2CHCHPh), 7.05-7.60 (m, 5H, C6H5). 1H NMR
(CD2Cl2, 25 °C): δ 1.50 (s, 15H, CH3 of Cp*), 1.86 (d, 1H,
Data for 8a (0.044 mmol, 85% based on NHdC(NMe2)Me
measured by 1H NMR) are as follows. 1H NMR (THF-d8, 25
°C): δ 2.15 (s, 3H, NHdC(NMe2)CH3), 3.01 (s, 6H, NHd
C(N(CH3)2)Me). 1H NMR (CD2Cl2, 25 °C): δ 2.18 (s, 3H, NHd
C(NMe2)CH3), 2.90 (s, 6H, NHdC(N(CH3)2)Me).
1
Data for 7 are as follows. H NMR (CDCl3, 25 °C): δ 1.32
(d, 15H, J (HP) ) 2.1 Hz, CH3 of Cp*), 1.92 (dd, 1H, J (HH) )
12.0 Hz, J (HP) ) 14.0 Hz, CHHCHCHPh), 3.17 (d, 1H,
J (HH) ) 7.0 Hz, CHHCHCHPh), 3.73 (dd, 1H, J (HH) ) 10.0
Hz, J (HP))14.0 Hz, CH2CHCHPh), 4.71 (m, 1H, CH2CHCHPh),

Acetonitrile in [Cp*Ir(η3-CH2CHCHPh)(NCMe)]+
Organometallics, Vol. 19, No. 4, 2000 647
Ta ble 1. Deta ils of Cr ysta llogr a p h ic Da ta Collection of th e Com p lexes 2a -E, 4a -Z, 5-K, a n d 6
2a -E
4a -Z
5-K
6
chemical formula
fw
C
24H34O3N2F3SIr
C23H31O4NF3SIr
666.75
293
0.2 × 0.3 × 0.3
monoclinic
P1121/n
8.4789(13)
13.491(3)
22.245(6)
90.00
92.68(2)
90.00
2541.8(9)
4
1.742
5.385
C21H28ONIr
502.64
293(2)
0.75 × 0.3 × 0.2
monoclinic
P21/n
7.475(10)
14.460(3)
17.647(3)
90.00
99.380(10)
90.00
1881.9(6)
4
1.774
7.101
984
C32H37O8NPS2F6Ir
982.93
293(2)
0.3 × 0.1 × 0.2
monoclinic
P21/n
20.2001(10)
9.0054(10)
20.8287(10)
90.00(5)
90.57(5)
90.00(5)
3788.8(5)
4
679.79
296(2)
0.3 × 0.4 × 0.5
monoclinic
P21/c
15.091(6)
11.4200(10)
15.603(2)
90.00
101.08(2)
90.00
2237.7(6)
4
1.711
5.187
1344
temp, K
cryst dimens, mm
cryst syst
space group
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
Z
F
(calc), g cm-1
1.723
3.757
1952
µ, mm-1
F(000)
1312
radiation
wavelength
2θ max, deg
hkl range
Mo KR
0.7107
50
-17 e h e 17
0 e k e 13
0 e l e 18
4399
Mo KR
Mo KR
0.7107
25
0 e h e 8
0 e k e 17
-20 e l e 20
3606
Mo KR
0.7107
0.7107
50
46.05
0 e h e 10
0 e k e 16
-26 e l e 26
4450
0 e h e 22
0 e k e 9
-22 e l e 22
5550
no. of reflcns
no. of unique data
4319
2358
3300
5279
no. of obs (|Fo| > 2σFo) data
4019
323
ω/ 2θ scan
0.031
2058
314
ω scan
0.024
2694
329
ω/ 2θ scan
0.024
2936
469
ω/ 2θ scan
0.067
no. of params
scan type
R1
wR2
0.077
0.054
0.058
0.1701
GOF
1.080
1.091
1.142
1.099
7.13-7.41 (m, 5H, C6H5), 7.63 (br s, 15H of PPh3). 31P NMR
(CDCl3, 25 °C): δ 11.2 (s, PPh3). 13C NMR (CDCl3, 25 °C): δ
8.28 (d, J (CP) ) 0.6 Hz, C5(CH3)5), 97.9 (d, J (CP) ) 2.0 Hz,
C5(Me)5), 37.0 (CH2CHCHPh), 58.2 (CH2CHCHPh), 73.9
(CH2CHCHPh), 126.5, 127.4, 128.8, 129.0 (d, J (CP) ) 10.0 Hz),
128.9, 131.8, 134.9 (d, J (CP) ) 9.5 Hz) and 136.9 (CH2-
CHCHPh and PPh3). IR (KBr, cm-1): 1031, 1149 and 1272 (s,
OTf). Anal. Calcd for C38H39O3PSF3Ir: C, 53.32; H, 4.59.
Found: C, 52.94; H, 4.14.
Rea ction of 2b a n d 4a -c w ith P P h 3. These reactions
were carried out in the same manner as described above for
the reaction of 2a with PPh3.
Data for NHdC(NHMe)Me (8b, 0.045 mmol, 86%) are as
follows. 1H NMR (CDCl3, 25 °C): δ 1.99 (s, 3H, NHdC(NHMe)-
CH3), 2.64 (s, 3H, NHdC(NHCH3)Me), 3.64 (br s, 1H, NHd
C(NHMe)Me), 6.95 (br s, 1H, NHdC(NHMe)Me).
stirred for 1 h at room temperature. AgCl was removed by
filtration, and the filtrate was vacuum distilled to obtain a
pale yellow solid, which was recrystallized in CHCl3/Et2O to
obtain pale yellow microcrystals of [Cp*Ir(η3-CH2CHCHPh)-
(NCCHdCHMe)]OTf (10, 0.13 g, 94%). 1H NMR (CDCl3, 25
°C): δ 1.58 and 1.61 (s, 15H, CH3 of Cp*), 2.1-2.2 (m, 3H,
NCCHdCHCH3), 2.47 (d, 1H, J (HH) ) 9.5 Hz, CHHCHCHPh),
3.40 and 3.45 (d, 1H, J (HH) ) 6.7 Hz, CHHCHCHPh), 4.16
(d, 1H, J (HH) ) 10.6 Hz, CH2CHCHPh), 5.0 (m, 1H, CH2CH-
CHPh), 6.8-7.0 and 7.0-7.2 (m, 1H, NCCHdCHMe), 6.1-6.2
(m, 1H, NCCHdCHMe), 7.2-7.4 (m, 5H, C6H5). 13C NMR
(CDCl3, 25 °C): δ 18.0 and 19.3 (NCCHdCHCH3), 7.80, 7.94,
94.7 and 94.8 (Cp*), 43.4 and 43.6 (CH2CHCHPh), 65.7 and
65.9 (CH2CHCHPh), 79.3 and 79.4 (CH2CHCHPh), 99.5 and
99.6 (NCCHdCHMe), 121 and 123 (NtC), 157.5 and 159.8
(NCCHdCHMe), 109.3, 126.7, 127.7, 129.6, 130.3, 134.1, 135.8
and 137.5 (C6H5). IR (KBr, cm-1): 1023, 1151 and 1260 (br s,
OTf). Anal. Calcd for C24H29O3NSF3Ir: C, 43.63; H, 4.42; N,
2.12. Found: C, 43.60; H, 4.38; N, 2.10.
Syn th esis of [Cp *Ir (η3-CH2CHCHP h )(NCP h )]OTf (11).
This compound was prepared in the same manner as described
for the synthesis of 10 using 0.10 g of 3 (0.21 mmol) in PhCN/
CH2Cl2 (v/v ) 3/10) solution. The yield was 0.12 g (82%) based
on [Cp*Ir(η3-CH2CHCHPh)(NCPh)]OTf (11). 1H NMR (CDCl3,
25 °C): δ 1.60 (s, 15H, CH3 of Cp*), 2.52 (d, 1H, J (HH) ) 10.0
Hz, CHHCHCHPh), 3.50 (d, 1H, J (HH) ) 7.0 Hz, CHHCH-
CHPh), 4.20 (d, 1H, J (HH) ) 11.0 Hz, CH2CHCHPh), 5.10 (m,
1H, CH2CHCHPh), 7.20-7.84 (m, 10H, CH2CHCHC6H5 and
C6H5CN). 13C NMR (CDCl3, 25 °C): δ 9.0 and 95.4 (Cp*), 44.4
(CH2CHCHPh), 66.3 (CH2CHCHPh), 80.1 (CH2CHCHPh),
122.5 (NtCPh), 109.3, 126.7, 127.7, 129.6, 130.3, 134.1, 135.8
and 137.5 (CH2CHCHC6H5 and C6H5CN). IR (KBr, cm-1):
1023, 1151 and 1260 (br s, OTf). Anal. Calcd for C27H29O3NSF3-
Ir: C, 46.54; H, 4.20; N, 2.01. Found: C, 46.52; H, 4.09; N,
1.99.
Data for NHdC(OMe)Me (9a , 0.043 mmol, 82%) are as
1
follows. H NMR (CDCl3, 25 °C): δ 2.01 (s, 3H, NHdC(OMe)-
CH3), 3.69 (s, 3H, NHdC(OCH3)Me), 6.92 (br s, 1H, NHd
C(OCH3)Me). 13C NMR (CDCl3, 25 °C, 125 MHz); δ 22.3 (NHd
C(OMe)CH3), 53.0 (NHdC(OCH3)Me).
Data for NHdC(OEt)Me (9b, 0.042 mmol, 80%) are as
1
follows. H NMR (CDCl3, 25 °C): δ 1.29 (t, 3H, J (HH) ) 7.0
Hz, NHdC(OCH2CH3)Me), 2.01 (s, 3H, NHdC(OEt)CH3), 4.10
(q, 2H, J (HH) ) 7.0 Hz, NHdC(OCH2CH3)Me). 1H NMR (THF-
d8, 25 °C): δ 1.37 (t, 3H, J (HH) ) 7.0 Hz, NHdC(OCH2CH3)-
Me), 2.05 (s, 3H, NHdC(OEt)CH3), 4.21 (q, 2H, J (HH) ) 7.0
Hz, NHdC(OCH2CH3)Me), 7.45 (br s, 1H, NHdC(OEt)Me). 13
C
NMR (CDCl3, 25 °C): δ 13.9 (NHdC(OCH2CH3)Me), 22.5
(NHdC(OEt)CH3), 61.2 (NHdC(OCH2CH3)Me), 170.2 (NHd
C(OEt)Me).
Data for NHdC(O-i-Pr)Me (9c, 0.042 mmol, 80%) are as
1
follows. H NMR (CDCl3, 25 °C): δ 1.25 (d, 6H, NHdC(OCH-
(CH3)2)Me), 1.98 (s, 3H, NHdC(O-i-Pr)CH3), 5.00 (m, 1H, NHd
C(OCH(Me)2)Me), 6.82 (br s, 1H, NHdC(O-i-Pr)Me).
Syn th esis of [Cp *Ir (η3-CH2CHCHP h )(NCCHdCHMe)]-
OTf (10). A 0.060 g (0.23 mmol) of AgOTf was added to a
MeCHdCHCN (1.0 mL: cis/trans ) 2/1)/CH2Cl2 (v/v ) 1/9)
solution of 3 (0.10 g, 0.21 mmol), and the reaction mixture was
Ca ta lytic Hyd r a tion of Nitr iles (RCN) w ith [Cp *Ir (η3-
CH2CHCHP h )(NCR)]OTf (R ) Me (1), MeCHdCH (10)).
The reaction mixture of RCN (16 mmol), H2O (100 mmol), Na2-
CO3 (100 mmol), and 0.08 mmol of iridium compound was

648 Organometallics, Vol. 19, No. 4, 2000
Chin et al.
heated at 70 °C in a 25 mL bomb type reactor under N2 for 1
h before it was cooled to room temperature. Organic com-
pounds in the reaction mixture were extracted with CDCl3 (5
mL), and the organic layer was dried with MgSO4. 1H NMR
spectroscopy and GC were used to analyze the product, RC-
(dO)NH2. The yields of MeC(dO)NH2 and MeCHdCHC(dO)-
NH2 were 4.1 (0.66 mmol) and 6.6% (1.05 mmol), respectively.
Ca t a lyt ic H yd r a t ion of Acet on it r ile (MeCN) w it h
Na 2CO3 in th e Absen ce of Com p ou n d 1. The reaction was
carried out in the same manner as described above for the
reaction of MeCN with H2O in the presence of 1 and Na2CO3
24 accurately centered reflections in each selected range. All
data were collected with the ω/ 2θ (for 2a -E, 5-K, and 6) and
ω (for 4a -Z) scan modes, respectively, and corrected for Lp
effects and absorption. The structures of these compounds were
solved by Patterson’s heavy atom methods (SHELXS-86 for
2a -E, 4a -Z and SHELXS-97 for 5-K, 6). Details of crystal-
lographic data collection are listed in Table 1. Bond distances
and angles, positional and thermal parameters, and anisotro-
pic thermal parameters have been included in the tables of
Supporting Information. Non-hydrogen atoms were refined by
full-matrix least-squares techniques (SHELXL-93 for 2a -E ,
4a -Z and SHELXL-97 for 5-K, 6). All hydrogen atoms were
placed at their geometrically calculated positions (d(CH) )
0.960 Å for methyl and 0.930 Å for aromatic) and refined riding
on the corresponding carbon atoms with isotropic thermal
parameters. The final R1 and wR2 (R1 ) [∑|Fo| - |Fc|/|Fo| and
1
except that compound 1 was not used. The H NMR spectrum
of the CDCl3 solution showed a very small signal due to CH3-
CONH2 (δ 2.06 ppm).
Ca ta lytic Meth a n olysis of Ben zon itr ile (P h CN) w ith
[Cp*Ir (η3-CH2CHCHP h )(NCP h )]OTf (11). The reaction mix-
ture of PhCN (16 mmol), MeOH (100 mmol), Na2CO3 (100
mmol), and 0.08 mmol of iridium compound was heated at 70
°C in a 25 mL bomb type reactor under N2 for 1 h before it
was cooled to room temperature. Organic compounds in the
reaction mixture were extracted with CDCl3 (5 mL). 1H NMR,
GC, and mass (M+ at m/z 135) spectra were used to analyze
the product, HNdC(OMe)Ph. The yield of HNdC(OMe)Ph was
3.2% (0.51 mmol).
2
wR2 ) [∑w(Fo2 - Fc )2/∑w(Fo2)2]0.5) values were 0.031 and 0.077
for 2a -E, 0.024 and 0.054 for 4a -Z, 0.024 and 0.058 for 5-K,
and 0.067 and 0.17 for 6, respectively.
Ack n ow led gm en t. The authors wish to thank the
Ministry of Education (BSRI-97-3412) and the Korea
Science and Engineering Foundation (Grant No. 97-05-
01-3) for their financial support of this study.
X-r a y Str u ctu r a l Deter m in a tion of [Cp *Ir (η3-CH2CH-
CHP h )(NH dC(NMe2)Me)]OTf (2a -E ), [Cp *Ir (η3-CH2CH-
CHP h )(NHdC(OMe)Me)]OTf (4a -Z), Cp *Ir (η3-CH2CHCH-
P h )(NHC(dO)Me) (5-K), an d [Cp*Ir (NHdC(OH)Me)(OH2)-
(P P h 3)](OTf)2 (6). Crystals were grown from CHCl3 (2a -E,
4a -Z, 6) and benzene (5-K). Diffraction data were collected on
an Enraf-Nonius CAD4 diffractometer with graphite-mono-
chromated Mo KR radiation at room temperature. Accurate
cell parameters were determined from the least-squares fit of
Su p p or tin g In for m a tion Ava ila ble: Tables of bond
distances and angles, positional and thermal parameters, and
anisotropic thermal parameters for complexes 2a -E, 4a -Z, 5-K,
and 6. This material is available free of charge via the Internet
at http://pubs.acs.org.
OM9908480