Synthesis of cross-conjugated olefins from alkynes: Regioselective C-C bond formation between alkynes

Article abstract of DOI:10.1021/om020410r

Reactions of cis-dihydrido complex [Ir(H)₂(NCCH₃)₂(PPh₃)₂] ⁺ (1) with HC≡CH and RC≡CH (R = C₆H₅, p-C₆H₄CH₃, cyclohex-1-enyl, C(CH₃)=CH₂, C(CH₃)₃) produce cross-conjugated hexatrienes (RCH=C(CH=CH₂)₂, R-HEX) and octatetraenes (H₂C=CH-CR=CH-C(-CH= CH₂)=CHR, R₂-OCT). Two molecules of HC≡CH are inserted into Ir-H bonds of 1 to give cis-bis(ethenyl) complex [Ir(CH==CH₂)₂(NCCH₃)₂(PPh₃ )₂]⁺ (2), which reacts with RC≡CD to produce both R-HEX-d₁ (RCD=C(CH=CH₂)₂) and R₂-OCT-d₂ (H₂C=CH-CR=CD-C(-CH= CH₂)=CDR). R-HEX are exclusively obtained from the reactions of RC≡CH with [Ir(CH= CH₂)₂(CO)₂(PPh₃)₂]⁺ (3). Alkynyl cis-bis(ethenyl) complexes Ir(CH=CH₂)₂(C≡CR)(CO)(PPh₃)₂ (4, R = C₆H₅ (a), p-C₆H₄CH₃ (b), cyclohex-1-enyl (c)) react with D⁺ to give η⁴-R-HEX-d₁ complexes [Ir(η⁴-RCD=C(CH=CH₂)₂)(CO)(PPh₃) ₂]⁺ (5-d₁) from which R-HEX-d₁ are obtained in the presence of a base. Di- and trinuclear alkynyl-bis(alkenyl) complexes [L₅Ir-C≡Cp-C₆H₄-C≡C-IrL₅ ] (7, L₅ = (-CH=CH₂)₂(CO)(PPh₃)₂) and [L₅Ir-C≡C-m,m-C₆H₃-(C≡C-IrL₅ )₂] (8, L₅ = (-CH=CH₂)₂(CO)(PPh₃)₂) react with H⁺ to produce extended cross-conjugated olefins, p-C₆H₄-(HEX)₂ and m,m-C₆H₃-(HEX)₃, respectively, in high yields. Plausible reaction pathways involve alkenyl-vinylidene complexes that undergo the C-C bond formation reaction between the two hydrocarbyl ligands to produce the cross-conjugated olefins.

Full text of DOI:10.1021/om020410r

Organometallics 2002, 21, 3889-3896
3889
Syn th esis of Cr oss-Con ju ga ted Olefin s fr om Alk yn es:
Regioselective C-C Bon d F or m a tion betw een Alk yn es
Chong Shik Chin,* Hyungeui Lee, Hyeyun Park, and Mieock Kim
Chemistry Department, Sogang University, Seoul 121-742, Korea
Received May 23, 2002
Reactions of cis-dihydrido complex [Ir(H)2(NCCH3)2(PPh3)2]+ (1) with HCtCH and RCt
CH (R ) C6H5, p-C6H4CH3, cyclohex-1-enyl, C(CH3)dCH2, C(CH3)3) produce cross-conjugated
hexatrienes (RCHdC(CHdCH2)2, R-HEX) and octatetraenes (H2CdCH-CRdCH-C(-CHd
CH2)dCHR, R2-OCT). Two molecules of HCtCH are inserted into Ir-H bonds of 1 to give
cis-bis(ethenyl) complex [Ir(CHdCH2)2(NCCH3)2(PPh3)2]+ (2), which reacts with RCtCD to
produce both R-HEX-d1 (RCDdC(CHdCH2)2) and R2-OCT-d2 (H2CdCH-CRdCD-C(-CHd
CH2)dCDR). R-HEX are exclusively obtained from the reactions of RCtCH with [Ir(CHd
CH2)2(CO)2(PPh3)2]+ (3). Alkynyl cis-bis(ethenyl) complexes Ir(CHdCH2)2(CtCR)(CO)(PPh3)2
(4, R ) C6H5 (a ), p-C6H4CH3 (b), cyclohex-1-enyl (c)) react with D+ to give η4-R-HEX-d1
complexes [Ir(η4-RCDdC(CHdCH2)2)(CO)(PPh3)2]+ (5-d1) from which R-HEX-d1 are obtained
in the presence of a base. Di- and trinuclear alkynyl-bis(alkenyl) complexes [L5Ir-CtC-
p-C6H4-CtC-IrL5] (7, L5 ) (-CHdCH2)2(CO)(PPh3)2) and [L5Ir-CtC-m,m-C6H3-(CtC-
IrL5)2] (8, L5 ) (-CHdCH2)2(CO)(PPh3)2) react with H+ to produce extended cross-conjugated
olefins, p-C6H4-(HEX)2 and m,m-C6H3-(HEX)3, respectively, in high yields. Plausible reaction
pathways involve alkenyl-vinylidene complexes that undergo the C-C bond formation
reaction between the two hydrocarbyl ligands to produce the cross-conjugated olefins.
In tr od u ction
oligomerization between different alkynes, we observed
cross-conjugated hexatrienes (RCHdC(CHdCH2)2, R-
HEX) and octatetraenes (H2CdCH-CRdCH-C(-CHd
CH2)dCHR, R2-OCT) produced from reactions of HCt
CH and RCtCH (R ) C6H5, p-C6H4CH3, cyclohex-1-
enyl, C(CH3)dCH2, C(CH3)3) in the presence of cis-
dihydrido-iridium(III) complex4 [Ir(H)2(NCCH3)2-
(PPh3)2]+ (1). This prompted us to look into the details
of the formation of those R-HEX and R2-OCT, and the
further utilization of these reactions. We now wish to
report the derivatives of those R-HEX that are selec-
tively and quantitatively produced from reactions of
terminal alkynes with iridium complexes and suggest
plausible mechanisms for the regioselective C-C bond
formation between the alkenyl and alkynyl ligands to
produce those R-HEX and R2-OCT.
Transition metal-mediated C-C bond formation be-
tween alkynes is probably the best way of synthesizing
highly conjugated polyenes that are specially designed.1
Those polyenes have attracted a great interest because
of their utility toward organic synthesis and unique
physical properties.1-3 It is likely that metal-alkynyls,
-alkenyls, and -vinylidenes are the intermediates that
are formed during the oligomerization of alkynes to
produce those polyenes.1b-j During the investigation on
(1) (a) Esteruelas, M. A.; Herrero, J .; Lo´pez, A. M.; Oliva´n, M.
Organometallics 2001, 20, 3202. (b) Brizius, G.; Pschirer, N. G.; Steffen,
W.; Stitzer, K.; zur Loye, H.-C.; Bunz, U. H. F. J . Am. Chem. Soc. 2000,
122, 12435. (c) Esteruelas, M. A.; Garc´ıa-Yebra, C.; Oliva´n, M.; On˜ate,
E.; Tajada, M. A. Organometallics 2000, 19, 5098. (d) Kishimoto, Y.;
Eckerle, P.; Miyatake, T.; Kainosho, M.; Ono, A.; Ikariya, T.; Noyori,
R. J . Am. Chem. Soc. 1999, 121, 12035. (e) Kasatkin, A.; Whitby, R. J .
J . Am. Chem. Soc. 1999, 121, 7039. (f) Shirakawa, E.; Yoshida, H.;
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A.; Straub, T.; Dash, A. K.; Eisen, M. S. J . Am. Chem. Soc. 1999, 121,
3014. (h) Burrows, A. D.; Green, M.; J effery, J . C.; Lynam, J . M.;
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H.; Scha¨fer, M.; Wolf, J .; Peters, K.; von Schnering, H. G. Angew.
Chem., Int. Ed. Engl. 1995, 34, 191. (j) Koltzenburg, S.; Eder, E.;
Stelzer, F.; Nuyken, O. Macromolecules 1999, 32, 21. (k) St. Clair, M.;
Schaefer, W. P.; Bercaw, J . E. Organometallics 1991, 10, 525. (l)
Guerin, F.; McConville, D. H.; Vittal, J . J .; Yap, G. A. P. Organome-
tallics 1998, 17, 1290. (m) Schrock, R. R.; Luo, S.; Lee, J . C., J r.;
Zanetti, N. C.; Davis, W. M. J . Am. Chem. Soc. 1996, 118, 3883.
(2) (a) Chien, J . C. W. Polyacetylene; Academic Press: New York,
1984. (b) Cost, G. In Comprehensive Polymer Science; Allen, G.,
Berington, J . C., Eds.; Pergamon Press: Oxford, U.K., 1989; Vol. 4.
(c) Salaneck, W. R.; Lundstrom, I.; Ranby, B. Conjugated Polymers
and Related Materials; Oxford University Press: New York, 1993. (d)
Mawatari, Y.; Tabata, M.; Sone, T.; Ito, K.; Sadahiro, Y. Macromol-
ecules 2001, 34, 3776. (e) Lam, J . W. Y.; Kong, X.; Dong, Y.; Cheuk, K.
K. L.; Xu, K.; Tang, B. Z. Macromolecules 2000, 33, 5027.
Resu lts a n d Discu ssion
Two molecules of HCtCH are inserted into Ir-H(D)
bonds of cis-dihydrido complex 1-d2 by a type of 1,2-
addition to produce cis-bis(ethenyl) complex 2-d2 (eq 1)
while unidentified iridium complexes are obtained from
the reactions of 1 with RCtCH.
(3) (a) Fallis, A. G.; Forgione, P.; Woo, S.; Legoupy, S.; Py, S.;
Harwig, C.; Rietveld, T. Polyhedron 2000, 19, 533. (b) Woo, S.; Squires,
N.; Fallis, A. G. Org. Lett. 1999, 1, 573. (c) Winkler, J . D. Chem. Rev.
1996, 96, 167.
Both R-HEX-d1 and R2-OCT-d2 are produced from the
reactions of 2 with RCtCH(D) (eq 2, Table 1) while
10.1021/om020410r CCC: $22.00 © 2002 American Chemical Society
Publication on Web 08/16/2002

3890 Organometallics, Vol. 21, No. 19, 2002
Chin et al.
Ta ble 1. P r od u ction of R-HEX (RCHdC(CHdCH2)2)
a n d R2-OCT
(H2CdCH-CRdCH-C(-CHdCH2)dCHR) fr om
Rea ction s of 2 ([Ir (CHdCH2)2(NCCH3)2(P P h 3)2]OTf)
a n d 3 ([Ir (CHdCH2)2(CO)2(P P h 3)2]OTf) w ith
Alk yn es (HCtCR)
product (%)a
entry Ir(III) complex
HCtCR R
R-HEX R2-OCT
1
2
3
4
5
6
7
8
9
2
2
2
2
2
3
3
3
3
3
C(CH3)dCH2
C6H5
p-C6H4CH3
cyclohex-1-enyl
C(CH3)3
C(CH3)dCH2
C6H5
p-C6H4CH3
cyclohex-1-enyl
C(CH3)3
14
59
63
76
78
86
41
37
24
22
in the reactions of 4 with H+ even in the presence of
excess RCtCH. Alkynylation of 2, unlike the reactions
of 3 (eq 4), causes a C-C bond formation between the
ethenyl groups to give η4-butadiene complexes 6 exclu-
sively (eq 5). Complexes 6 do not undergo further C-C
∼100
∼100
∼100
∼100
∼100
10
a
Determined by GC of crude products.
bond formation between the alkynyl and butadiene
groups even in the presence of H+. η4-Hexatriene
(R-HEX) complexes have not been observed during the
reactions of 2 or 3 with RCtCH.
To see further C-C coupling between alkynyl and
alkenyl groups to produce cross-conjugated olefins, di-
and trinuclear alkynyl-bis(alkenyl) complexes 7 and 8
have been prepared in the same manner (see Experi-
mental Section) and their reactions with H+ have been
found to produce extended cross-conjugated olefins,
p-C6H4-(HEX)2 and m,m-C6H3-(HEX)3, respectively, in
high yields (eqs 6 and 7). These results (eqs 6 and 7)
R-HEX-d1 are exclusively obtained from the reactions
of RCtCH(D) with cis-dicarbonyl-cis-bis(ethenyl) com-
plex 3 (eq 3, Table 1) that is prepared by the reaction
of 2 with CO (eq 1). Relative yields of R-HEX to R2-
OCT vary with substituent R of RCtCH (see Table 1).
Different dimers (cis-PhCHdCH-CtCPh (0.26 mmol),
trans-PhCHdCH-CtCPh (0.01 mmol), CH2dCPh-Ct
CPh (0.05 mmol)) of PhCtCH are catalytically obtained
after the production of Ph-HEX and Ph2-OCT when an
excess of PhCtCH (3.0 mmol) is used in the reaction of
2 (0.1 mmol) at 50 °C for 48 h. Reaction of 3 (0.1 mmol)
with excess PhCtCH (3.0 mmol), however, produces cis-
PhCHdCH-CtCPh (0.5 mmol) exclusively and cata-
lytically after the quantitative production of Ph-HEX
under the same experimental conditions.
Isolated iridium complexes “Ir-A” in eq 2 and
“Ir-B” in eq 3 have not been unequivocally identified
while they seem to contain “Ir(RCtCH)2(NCCH3)2-
(PPh3)2” and “Ir(RCtCH)2(CO)2(PPh3)2”, respectively,
since reactions of “Ir-A” and “Ir-B” with H2 give cis-
dihydrido complexes 1 and [Ir(H)2(CO)2(PPh3)2]+ (1′),
respectively, in high yields and RCHdCH-CHdCHR.
During the investigation on the possible intermedi-
ates formed in the production of R-HEX and R2-OCT,
it has been found that reactions of 3 with RCtCH in
the presence of a base (Me3NO) produce alkynyl-cis-
bis(ethenyl) complexes 4 that readily react with H+ to
initiate the C-C bond formation between the two
ethenyl and alkynyl groups to give η4-R-HEX complexes
5 from which R-HEX are separated in the presence of
a base (L′) (eq 4). No R2-OCT has been observed at all
are strikingly different from what we observed from
reaction of similar binuclear alkynyl-bis(alkenyl) com-
plex 10 with H+ that gives the conjugated dienyne 11
(eq 8).5
(4) (a) Schrock, R. R.; Osborn, J . A. J . Am. Chem. Soc. 1976, 98,
2134. (b) Crabtree, R. H. Acc. Chem. Res. 1979, 12, 331.

Synthesis of Cross-Conjugated Olefins from Alkynes
Organometallics, Vol. 21, No. 19, 2002 3891
Sch em e 1
byl ligands are so stable that no reductive elimination
of unsaturated hydrocarbons occurs even at elevated
temperature.
Metal-vinylidenes (MdCdCHR) are frequently ob-
served and suggested in the reactions of metal-alkynyls
with protons and of metals with terminal alkynes (RCt
CH).9,10 The R-carbon (MdCdCHR) of the vinylidene
group is known to be so electrophilic that it readily
interacts with a neighboring hydrocarbyl ligand to form
a new C-C bond.10
Scheme 1 is accordingly suggested for the formation
of R-HEX from the reactions of 4 with proton (eq 4).
While no vinylidene intermediate is detected even at
low temperature during the reactions of 4 (eq 4), the
formation of isotopomers 5-d1 and R-HEX-d1 strongly
supports the vinylidene complexes A-d1 as the initial
intermediates that undergo the C-C coupling reaction
between the vinylidene and the cis-ethenyl groups to
produce another intermediate B-d1. These 16-electron
Ir(III) complexes B-d1 then undergo the reductive C-C
coupling reaction between the two hydrocarbyl ligands
to give the stable 18-electron Ir(I) complexes 5-d1.
Production of p-C6H4-(HEX)2 (eq 6) and m,m-C6H3-
(HEX)3 (eq 7) may also be understood by reaction
schemes similar to Scheme 1. A similar reaction path-
way may also be applicable to the formation of R-HEX
in reactions of 3 with RCtCH (eq 3).
Figu r e 1. ORTEP drawing of Ir(-CHdCH2)2(-CtCC6H9)-
(CO)(PPh3)2 (4c) with 50% thermal ellipsoids probability.
Selected bond distances (Å): Ir-C77 ) 2.106(13); Ir-C79
2.081(14); Ir-C81 ) 2.097(11); Ir-C83 ) 1.892(14); C71
)
-
C72 ) 1.330(2); C71-C76 ) 1.450(2); C77-C78 ) 1.165(17);
C79-C80 ) 1.270(2); C81-C82 ) 1.322(18); C83-O ) 1.150-
(15). Selected bond angles (deg): Ir-C77-C78 ) 176.6(11);
Ir-C79-C80 ) 138.4(12); Ir-C81-C82 ) 129.9(11); Ir-
C83-O ) 173.6(12).
New iridium complexes (2-8) have been unambigu-
ously characterized by detailed spectral and elemental
analysis data, crystal structure determination by X-ray
diffraction data analysis for 4c (Figure 1), and FAB
mass measurements for 7 and 8 (see Experimental
Section and Supporting Information). The characteriza-
tion is straightforward as similar compounds have been
recently prepared in this laboratory.6 Di- and trinuclear
complexes with bridging benzene 1,4-diethynyl, p-C6H4-
(-CtC-)2, and 1,3,5-triethynyl, m,m-C6H3(-CtC-)3,
also have been recently reported.7 Products of reactions
of 4, 7, and 8 with H+ also support the identification of
these complexes as shown in eqs 4, 6, and 7.
The geometry of R-HEX in 5 is clearly determined
by detailed spectral data analysis (see Experimental
Section and Supporting Information) and also supported
by the structure of isolated R-HEX. The 31P NMR
spectra of 5 show two signals (δ -5.94 to -7.76, 1.48 to
5.71) as does the very similar rhodium(I)-η4-1,3-buta-
diene complex (PPh3)2ClRh(η4-H2CdCH-C(Ph)dCH2),
whose crystal structure shows the two PPh3 being
nonequivalent.8 Cross-conjugated olefins, R-H E X,
R-HEX-d1, p-C6H4-(HEX)2, m,m-C6H3-(HEX)3, R2-OCT,
and R2-OCT-d2 have been unequivocally identified by
detailed spectral data (see Experimental Section and
Supporting Information). Those 18-electron iridium(III)
complexes (4, 7, 8) containing three σ-bonded hydrocar-
(9) (a) Castarlenas, R.; Esteruelas, M. A.; On˜ate, E. Organometallics
2001, 20, 3283. (b) Bustelo, E.; J ime´nez-Tenorio, M.; Puerta, M. C.;
Valerga, P. Organometallics 1999, 18, 4563. (c) Cadierno, V.; Gamasa,
M. P.; Gimeno, J . Organometallics 1999, 18, 2821. (d) de los R´ıos, I.;
J ime´nez-Tenorio, M.; Puerta, M. C.; Valerga, P. J . Am. Chem. Soc.
1997, 119, 6529.
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19, 3145. (b) J ime´nez-Tenorio, M. A.; J ime´nez-Tenorio, M.; Puerta, M.
C.; Valerga, P. Organometallics 2000, 19, 1333. (c) Yang, J .-Y.; Huang,
S.-L.; Lin, Y.-C.; Liu, Y.-H.; Wang, Y. Organometallics 2000, 19, 269.
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C.; Buil, M. L.; Esteruelas, M. A.; On˜ate, E.; Valero, C. Organometallics
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L.; Masi, D.; Peruzzini, M.; Rossi, R.; Romerosa, A. Organometallics
1999, 18, 4501. (h) Slugovc, C.; Mereiter, K.; Schmid, R.; Kirchner, K.
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(j) O’Connor, J . M.; Hiibner, K.; Merwin, R.; Gantzel, P. K.; Fong, B.
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6, 3965. (l) Yang, S.-M.; Chan, M. C.-W.; Cheung, K.-K.; Che, C.-M.;
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Res. 2002, 35, 218.
(6) Results will be reported elsewhere.
(7) (a) Weyland, T.; Ledoux, I.; Brasselet, S.; Zyss, J .; Lapinte, C.
Organometallics 2000, 19, 5235. (b) Leininger, S.; Stang, P. J .
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3892 Organometallics, Vol. 21, No. 19, 2002
Chin et al.
Sch em e 2
Exp er im en ta l Section
Gen er a l In for m a tion . A standard vacuum system and
Schlenk type glass ware were used in most of the experiments
in handling metal complexes although most of the compounds
are stable enough to be handled in air.
PhCtCD and HBF4‚OEt2 (54 wt % in Et2O) were purchased
from Aldrich and aqueous DBF4 solution was prepared by
mixing of HBF4 (1 mL, 54 wt % in Et2O) with D2O (4 mL).
1,4-Diethynylbenzene,11 1,3,5-triethynylbenzene,7b and [Ir(H)2-
(NCCH3)2(PPh3)2]OTf (1)4 were prepared by the literature
method.
In str u m en ts. NMR spectra were recorded on a Varian 300
Formation of the dienyne 11 (eq 8) is not explained
simply by a reaction pathway similar to Scheme 1 and
is currently under investigation.
1
or 500 MHz spectrometer for H, 75 or 125.7 MHz for 13C, and
81 MHz for 31P. Infrared spectra were obtained on a Nicolet
205. Electronic absorption spectra were measured with a
Hewlett-Packard HP8453 diode array spectrophotometer.
Melting points were measured with an Electrothermal IA9000
series Digital Meting point apparatus. Elemental analyses
were carried out with a Carlo Erba EA1108. Gas chromatog-
raphy/mass spectra were measured with a Hewlett-Packard
HP 5890A VG-trio 2000 at the Organic Chemistry Center,
Sogang University. FAB mass measurements were carried out
with a J MS-HX110/110A tandem mass spectrometer at the
Korea Basic Science Institute.
Syn th esis. (a ) P r ep a r a tion of [Ir (-CHdCH2)2(NCCH3)2-
(P P h 3)2]OTf (2). A 0.1-g (0.1 mmol) sample of 1 in CH2Cl2
(10 mL) was stirred under HCtCH (1 atm) at 0 °C for 5 h
before n-pentane (30 mL) was added to precipitate beige
microcrystals which were collected by filtration, washed with
n-pentane (3 × 10 mL), and dried under vacuum. The yield
was 0.11 g and 98% based on [Ir(-CHdCH2)2(NCCH3)2(PPh3)2]-
OTf (2). 1H NMR (500 MHz, CDCl3): δ 7.3-7.6 (m, 30H,
P(C6H5)3), 7.52 (ddt, 2H, J (HH) ) 18.0 Hz, J (HH) ) 10.0 Hz,
J (HP) ) 3.8 Hz, Ir-CHdCH2), 5.68 (d, 2H, J (HH) ) 10.0 Hz,
Ir-CHdCHH), 4.61 (d, 2H, J (HH) ) 18.0 Hz, Ir-CHdCHH),
1.72 (s, 6H, CH3CN). 13C NMR (125.7 MHz, CDCl3): δ 125.1
(t, J (CP) ) 10.1 Hz, Ir-CHdCH2), 121.4 (t, J (CP) ) 4.0 Hz,
Ir-CHdCH2), 119.5 (s, CH3CN), 2.9 (s, CH3CN), 134.8, 130.3,
128.7, and 127.7 (P(C6H5)3). HETCOR (1H (500 MHz) f 13C
(125.7 MHz)): δ 7.52 f 125.1; 4.61, 5.68 f 121.4; 1.72 f 2.9.
31P{1H} NMR (81 MHz, CDCl3): δ -8.75 (s, PPh3). IR
(KBr, cm-1): 2035 (w, νCtN), 1562 (m, νCdC), 1271, 1152 and
1032 (s, due to uncoordinated OTf). Anal. Calcd for IrF3-
SO3P2C45H42N2: C, 53.94; H, 4.22; N, 2.79. Found: C, 53.84;
H, 4.33; N, 2.72.
Scheme 2 is proposed for the production of R-HEX-
d1 and R2-OCT-d2 in eq 2. The isotopomers B′-d1 are
the likely intermediates to give the observed isoto-
pomers R-HEX-d1 for the same reason discussed above
with Scheme 1. Since the linear trienes CH2dCHCHd
CRCHdCH2 have not been detected during the reac-
tions of 2 with RCtCH, it is less likely that the first
RCtCD is added to 2 via a type of 1,2-addition to
give [(PPh3)2(CH3CN)2Ir(-CDdCR-CHdCH2)(-CHd
CH2)]+ which are therefore excluded in Scheme 2. The
intermediates B′-d1 then undergo the 1,2-insertion of
another RCtCD into one of the two Ir-C bonds to give
C′-d2 and/or D′-d2 that finally eliminate R2-OCT-d2. The
structure of R2-OCT and positions of deuterium in R2-
OCT-d2 strongly support the second RCtCH insertion
by a type of 1,2-addition (B′ f C′, D′) rather than 1,1-
addition via the vinylidene species (such as A f B in
Scheme 1 or 2 f B′ in Scheme 2). No direct evidence
has been obtained yet to distinguish the two pathways
via C′ and D′ for the formation of R2-OCT.
It is noticed in Table 1 that the R-HEX/R2-OCT is
larger with bulkier R substituents. This may be under-
stood by the steric effects of R experienced during the
formation of R2-OCT, which requires more space around
the metal than the formation of R-HEX does.
The different reactivity of 2 and 3 toward RCtCH
(see eqs 2 and 3 and Table 1) could be due to the relative
lability of CH3CN in 2 and CO in 3. The CH3CN of 2 is
readily replaced by CO whereas the CO of 3 seems to
be even more strongly bound to the metal than PPh3.
It is likely that B′ are far easier to interact with another
RCtCH because the CH3CN ligands in B′ are more
labile than the PPh3 ligands in B′′ ([(PPh3)2(CO)2Ir(-
C(dCHR)CHdCH2)(-CHdCH2)]+) that are presumably
suggested as the intermediates in reactions of 3 with
RCtCH. It is therefore expected for B′′ to give more
cross-conjugated trienes R-H E X rather than to react
with a second RCtCH to give R2-OCT. It may be said
that replacing the labile CH3CN ligands of 2 with
relatively inert CO to produce 3 effectively increases the
selectivity of the products (i.e., R-HEX/R2-OCT).
(b) P r ep a r a tion of [Ir (-CHdCHD)2(NCCH3)2(P P h 3)2]-
OTf (2-d 2). This compound was prepared in the same manner
as described above for 2 by using 1-d2. 1H NMR (500 MHz,
CDCl3): δ 7.3-7.6 (m, 30H, P(C6H5)3), 7.52 (dt, 2H, J (HH) )
10.0 Hz, J (HP) ) 3.8 Hz, Ir-CHdCHD), 5.68 (d, 2H, J (HH)
) 10.0 Hz, Ir-CHdCHD), 1.72 (s, 6H, CH3CN).
(c) P r ep a r a tion of [Ir (-CHdCH2)2(CO)2(P P h 3)2]OTf (3).
A 0.1-g (0.1 mmol) sample of 2 in CH2Cl2 (10 mL) was stirred
under CO (1 atm) at 25 °C for 3 h before n-pentane (30 mL)
was added to precipitate beige microcrystals which were
collected by filtration, washed with n-pentane (3 × 10 mL),
and dried under vacuum. The yield was 0.96 g and 98% based
on [Ir(-CHdCH2)2(CO)2(PPh3)2]OTf (3). 1H NMR (500 MHz,
CDCl3): δ 7.5-7.7 (m, 30H, P(C6H5)3), 6.59 (ddt, 2H, J (HH) )
18.5 Hz, J (HH) ) 10.5 Hz, J (HP) ) 4.5 Hz, Ir-CHdCH2), 6.37
(d, 2H, J (HH) ) 10.5 Hz, Ir-CHdCHH), 5.06 (d, 2H, J (HH)
) 18.5 Hz, Ir-CHdCHH). 13C NMR (125.7 MHz, CDCl3): δ
167.0 (t, J (CP) ) 5.8 Hz, Ir-CO), 130.6 (t, J (CP) ) 4.5 Hz,
Ir-CHdCH2), 129.6 (t, J (CP) ) 10.3 Hz, Ir-CHdCH2), 134.4,
132.2, 128.8 and 127.3 (P(C6H5)3). HETCOR (1H (500 MHz) f
13C (125.7 MHz)): δ 6.59 f 129.6; 5.06, 6.37 f 130.6. 31P{1H}
NMR (81 MHz, CDCl3): δ -17.40 (s, PPh3). IR (KBr, cm-1):
Equations 2, 3, 6, and 7 are all stoichiometric reac-
tions. Catalytic production of those cross-conjugated
olefins seems quite feasible under the appropriate
conditions since complexes 1 and 1′ are recovered in
high yields from the reactions of “Ir-A” and “Ir-B” with
H2. It seems also possible that the method to form new
C-C bonds described in this paper is further utilized
to prepare more highly cross-conjugated olefins.
(11) J ung, J . K.; Kim, D. K.; Cho, D. H.; Yoon, B. I.; Kim, K. S.
Polymer (Korea) 1993, 17, 67.

Synthesis of Cross-Conjugated Olefins from Alkynes
Organometallics, Vol. 21, No. 19, 2002 3893
2121, 2086 (s, νCO), 1574 (m, νCdC), 1278, 1151 and 1032 (s,
(m, 1H, Ir-CtC-CdCH-(CH2)3CH2), 5.18 (ddt, J (HH) ) 19.0
Hz, J (HH) ) 3.0 Hz, J (HP) ) 2.0 Hz) and 4.90 (ddt, J (HH) )
19.0 Hz, J (HH) ) 3.0 Hz, J (HP) ) 1.5 Hz) (2H, Ir-CHdCHH),
due to uncoordinated OTf). Anal. Calcd for IrF3SO5P2C43H46
:
C, 52.38; H, 4.70. Found: C, 52.51; H, 4.77.
(d ) P r ep a r a tion of [Ir (-CHdCHD)2(CO)2(P P h 3)2]OTf
(3-d 2). This compound was prepared in the same manner as
described above for 3 by using 2-d2. 1H NMR (500 MHz,
CDCl3): δ 7.5-7.7 (m, 30H, P(C6H5)3), 6.59 (dt, 2H, J (HH) )
10.5 Hz, J (HP) ) 4.5 Hz, Ir-CHdCHD), 6.37 (d, 2H, J (HH)
) 10.5 Hz, Ir-CHdCHD).
2.03, 1.79 and 1.52 (m, 8H, Ir-CtC-CdCH(CH2)3CH2). 13C
NMR (125.7 MHz, CDCl3): δ 174.1 (t, J (CP) ) 6.5 Hz, Ir-
CO), 143.5 (t, J (CP) ) 8.9 Hz) and 135.6 (t, J (CP) ) 12.5 Hz)
(Ir-CHdCH2), 125.3 (s, Ir-CtC-CdCH-(CH2)3CH2)), 126.3
(br s, Ir-CtC-CdCH(CH2)3CH2), 125.2 (t, J (CP) ) 4.9 Hz)
and 123.1 (br s) (Ir-CHdCH2), 114.1 (s, Ir-CtC), 82.7 (t,
J (CP) ) 13.1 Hz, Ir-CtC), 30.3, 25.4, 22.8 and 22.2 (br s, Ir-
(e) P r ep a r a tion of Ir (-CtCR)(-CHdCH2)2(CO)(P P h 3)2
(4, R ) C6H5 (a ), p-C6H4CH3 (b), cycloh ex-1-en yl (c)). These
compounds were prepared by the same method as described
below for 4a . To a solution of 3 (0.1 g, 0.1 mmol) and C6H5Ct
CH (0.012 g, 0.12 mmol) in CHCl3 (10 mL) was added Me3NO
(0.019 g, 0.25 mmol) and the reaction mixture was stirred at
25 °C under N2 for 30 min before the pale yellow solution
turned light brown. Excess Me3NO and [HNMe3]OTf were
removed by extraction with H2O (2 × 10 mL). Addition of
n-pentane (20 mL) resulted in precipitation of beige microc-
rystals that were collected by filtration, washed with n-pentane
(3 × 10 mL), and dried under vacuum. The yield was 0.074 g
and 82% based on Ir(-CtCC6H5)(-CHdCH2)2(CO)(PPh3)2
(4a ). 1H NMR (500 MHz, CDCl3): δ 6.9-7.8 (m, 36H, P(C6H5)3,
CtCC6H5, and Ir-CHdCH2), 6.22 (ddt, 1H, J (HH) ) 19.0 Hz,
J (HH) ) 11.0 Hz, J (HP) ) 2.5 Hz, Ir-CHdCH2), 5.87 (ddt,
J (HH) ) 11.5 Hz, J (HH) ) 2.5 Hz, J (HP) ) 2.0 Hz) and 5.77
(ddt, J (HH) ) 11.0 Hz, J (HH) ) 3.0 Hz, J (HP) ) 1.5 Hz) (2H,
Ir-CHdCHH), 5.19 (ddt, J (HH) ) 19.0 Hz, J (HH) ) 2.5 Hz,
J (HP) ) 2.0 Hz) and 4.92 (ddt, J (HH) ) 19.0 Hz, J (HH) ) 3.0
Hz, J (HP) ) 1.5 Hz) (2H, Ir-CHdCHH). 13C NMR (125.7 MHz,
CDCl3): δ 173.9 (t, J (CP) ) 6.5 Hz, Ir-CO), 143.0 (t, J (CP) )
8.9 Hz) and 135.2 (t, J (CP) ) 12.8 Hz) (Ir-CHdCH2), 125.3
(t, J (CP) ) 5.0 Hz) and 123.5 (br s) (Ir-CHdCH2), 112.0 (s,
Ir-CtC), 89.6 (t, J (CP) ) 12.5 Hz, Ir-CtC), 130.1 (Cipso of
C6H5 carbons), 130.8, 127.5 and 124.4 (CH of C6H5 carbons),
135.0, 131.3, 129.9 and 127.3 (P(C6H5)3). HETCOR (1H (500
MHz) f 13C (125.7 MHz)): δ 6.22 f 143.0; 5.87, 5.19 f 125.3;
5.77, 4.92 f 123.5. 31P{1H} NMR (81 MHz, CDCl3): δ -12.44
(s, PPh3). IR (KBr, cm-1): 2108 (m, νCtC), 2045 (s, νCO). Anal.
Calcd for IrOP2C49H41: C, 65.39; H, 4.59. Found: C, 65.01; H,
4.48.
Ir(-CtC-p-C6H4CH3)(-CHdCH2)2(CO)(PPh3)2 (4b): 1H NMR
(500 MHz, CDCl3): δ 7.2-7.9 (m, 31H, P(C6H5)3 and Ir-CHd
CH2), 6.7-7.0 (AB quartet with ∆ν/J ) 10.1, 4H, J (HAHB) )
81.1 Hz, Ir-CtC-p-C6H4CH3), 6.20 (ddt, 1H, J (HH) ) 19.0 Hz,
J (HH) ) 11.5 Hz, J (HP) ) 2.5 Hz, Ir-CHdCH2), 5.84 (ddt,
J (HH) ) 11.5 Hz, J (HH) ) 3.0 Hz, J (HP) ) 2.0 Hz) and 5.74
(ddt, J (HH) ) 11.5 Hz, J (HH) ) 3.0 Hz, J (HP) ) 1.5 Hz) (2H,
Ir-CHdCHH), 5.17 (ddt, J (HH) ) 18.5 Hz, J (HH) ) 3.0 Hz,
J (HP) ) 2.0 Hz) and 4.90 (ddt, J (HH) ) 19.0 Hz, J (HH) ) 3.0
Hz, J (HP) ) 1.5 Hz) (2H, Ir-CHdCHH), 2.29 (s, CH3, 3H).
13C NMR (125.7 MHz, CDCl3): δ 173.9 (t, J (CP) ) 6.5 Hz, Ir-
CO), 143.0 (t, J (CP) ) 8.9 Hz) and 135.3 (t, J (CP) ) 5.0 Hz)
(Ir-CHdCH2), 125.3 (t, J (CP) ) 5.0 Hz) and 123.3 (br s) (Ir-
CHdCH2), 111.8 (s, Ir-CtC), 87.5 (t, J (CP) ) 13.1 Hz, Ir-
CtC), 21.2 (s, p-C6H4CH3), 133.9 and 130.1 (Cipso of p-C6H4CH3
carbons), 130.6 and 128.2 (CH of p-C6H4CH3 carbons), 135.0,
131.3, 130.0 and 127.3 (P(C6H5)3). HETCOR (1H (500 MHz) f
13C (125.7 MHz)): δ 6.20 f 143.0; 5.84, 5.17 f 125.3; 5.74,
4.90 f 123.3; 2.29 f 21.2. 31P{1H} NMR (81 MHz, CDCl3): δ
-12.38 (s, PPh3). IR (KBr, cm-1): 2107 (m, νCtC), 2027 (s, νCO).
Anal. Calcd for IrOP2C50H43: C, 65.70; H, 4.74. Found: C,
65.94; H, 4.83.
CtC-CdCH(CH2)3CH2), 127.2, 129.9, 131.4 and 135.0
(P(C6H5)3). HETCOR (1H (500 MHz) f 13C (125.7 MHz)): δ
7.24 f 135.6; 6.17 f 143.5; 5.85, 5.18 f 125.2; 5.72, 4.90 f
123.1; 5.38 f 126.3; 2.03 f 25.4; 1.79 f 30.3; 1.52 f 22.2,
22.8. 31P{1H} NMR (81 MHz, CDCl3): δ -12.99 (s, PPh3). IR
(KBr, cm-1): 2097 (m, νCtC), 2017 (s, νCO). Anal. Calcd for
IrOP2C49H45: C, 65.10; H, 5.02. Found: C, 65.39; H, 5.09.
(f) P r ep a r a tion of Ir (η4-CH2dCH-CHdCH2)(-CtCR)-
(P P h 3)2 (6, R ) C6H5 (a ), p-C6H4CH3 (b)). To a solution of 2
(0.1 g, 0.1 mmol) and C6H5CtCH (0.012 g, 0.12 mmol) in
CHCl3 (10 mL) was added NEt3 (0.019 g, 0.25 mmol) and the
reaction mixture was stirred at 25 °C under N2 for 6 h before
the pale yellow solution turned light brown. Excess NEt3 and
[HNEt3]OTf were removed by extraction with H2O (5 × 10 mL).
Addition of n-pentane (10 mL) at -78 °C resulted in precipita-
tion of beige microcrystals that were collected by filtration,
washed with cold n-pentane (3 × 10 mL), and dried under
vacuum. The yield was 0.078 g and 89% based on Ir(η4-CH2d
1
CH-CHdCH2)(-CtCC6H5)(PPh3)2 (6a ). H NMR (500 MHz,
CDCl3): δ 6.8-7.6 (m, 35H, P(C6H5)3, C6H5), 5.51 and 5.16 (m,
2H, Ir-η4-CH2dCHCHdCH2), 2.80 and 1.60 (m, 2H, Ir-η4-
CHsynHdCHCHdCHsynH), -0.54 (m, 2H, Ir-η4-CHHantid
CHCHdCHHanti). 13C NMR (125.7 MHz, CDCl3): δ 105.5 (s,
Ir-CtC), 95.8 (t, J (CP) ) 12.8 Hz, Ir-CtC), 88.7 (s) and 80.8
(t, J (CP) ) 6.1 Hz) (Ir-η4-CH2dCHCHdCH2), 38.2 and 33.1
(s, Ir-η4-CH2dCHCHdCH2). HETCOR (1H (500 MHz) f 13C
(125.7 MHz)): δ 5.51 f 80.8; 5.16 f 88.7; 2.80, -0.54 f 38.2;
1.60, -0.54 f 33.1. 31P{1H} NMR (81 MHz, CDCl3): δ 6.46
(d, J (PP) ) 17.9 Hz, PPh3), -7.41 (d, J (PP) ) 17.9 Hz, PPh3).
IR (KBr, cm-1): 2102 (m, νCtC). Anal. Calcd for IrOP2C48H41
:
C, 65.39; H, 4.59. Found: C, 65.32, H, 4.54.
Ir(η4-CH2dCH-CHdCH2)(-CtC-p-C6H4CH3)(PPh3)2 (6b)
1H NMR (500 MHz, CDCl3): δ 6.9-7.8 (m, 30H, P(C6H5)3),
6.5-6.8 (AB quartet with ∆ν/J ) 9.8, 4H, J (HAHB) ) 78.6 Hz,
CtC-p-C6H4CH3,), 5.34 and 5.03 (m, 2H, Ir-η4-CH2dCHCHd
CH2), 2.65 and 1.42 (m, 2H, Ir-η4-CHsynHdCHCHdCHsynH),
2.29 (s, 3H, CtC-p-C6H4CH3) -0.69 (m, 2H, Ir-η4-CHHantid
CHCHdCHHanti). 13C NMR (125.7 MHz, CDCl3): δ 104.9 (s,
Ir-CtC), 94.3 (t, J (CP) ) 12.8 Hz, Ir-CtC), 87.6 (s) and 79.6
(t, J (CP) ) 6.0 Hz) (Ir-η4-CH2dCHCHdCH2), 38.2 and 33.1
(s, Ir-η4-CH2dCHCHdCH2), 20.2 (s, CtC-p-C6H4CH3). 31P{1H}
NMR (81 MHz, CDCl3): δ 6.21 (d, J (PP) ) 17.8 Hz, PPh3),
-7.82 (d, J (PP) ) 17.8 Hz, PPh3). IR (KBr, cm-1): 2101 (m,
νCtC). Anal. Calcd for IrOP2C49H43: C, 66.42; H, 4.89. Found:
C, 66.29; H, 4.78.
(g) P r ep a r a tion of p-C6H4(-CtC-Ir L5)2 (7, L5 ) (-CHd
CH2)2(CO)(P P h 3)2). To a solution of 3 (0.2 g, 0.2 mmol) and
p-C6H4(-CtCH)2 (0.013 g, 0.11 mmol) in CHCl3 (10 mL) was
added Me3NO (0.038 g, 0.50 mmol) and the reaction mixture
was kept at 25 °C under N2 for 2 h before excess Me3NO and
[HNMe3]OTf were removed by extraction with H2O (2 × 10
mL). Addition of n-pentane (20 mL) resulted in precipitation
of beige microcrystals that were collected by filtration, washed
with CH3OH (3 × 10 mL), and dried under vacuum. The yield
Ir(-CtC-cyclohex-1-enyl)(-CHdCH2)2(CO)(PPh3)2 (4c): 1H
NMR (500 MHz, CDCl3): δ 7.3-7.8 (m, 30H, P(C6H5)3), 7.24
(ddt, J (HH) ) 19.0 Hz, J (HH) ) 11.5 Hz, J (HP) ) 4.5 Hz)
and 6.17 (ddt, J (HH) ) 19.0 Hz, J (HH) ) 11.5 Hz, J (HP) )
2.0 Hz) (2H, Ir-CHdCH2), 5.85 (ddt, J (HH) ) 11.3 Hz, J (HH)-
) 3.0 Hz, J (HP) ) 2.0 Hz) and 5.72 (ddt, J (HH) ) 11.5 Hz,
J (HH) ) 3.0 Hz, J (HP) ) 1.5 Hz) (2H, Ir-CHdCHH), 5.38
was 0.064 g and 74% based on p-C6H4-(CtC-IrL5)2 (7, L5
)
(-CHdCH2)2(CO)(PPh3)2).1H NMR (500 MHz, CDCl3): δ 7.2-
7.8 (m, 62H, P(C6H5)3 and Ir-CHdCH2), 6.63 (s, 4H, Ir-Ct
C-C6H4,), 6.18 (ddt, 2H, J (HH) ) 19.0 Hz, J (HH) ) 11.5 Hz,

3894 Organometallics, Vol. 21, No. 19, 2002
Chin et al.
J (HP) ) 2.5 Hz, Ir-CHdCH2), 5.83 (ddt, J (HH) ) 11.5 Hz,
J (HH) ) 3.0 Hz, J (HP) ) 2.0 Hz) and 5.72 (ddt, J (HH) ) 11.5
Hz, J (HH) ) 3.0 Hz, J (HP) ) 1.5 Hz) (4H, Ir-CHdCHH), 5.16
(ddt, J (HH) ) 18.5 Hz, J (HH) ) 3.0 Hz, J (HP) ) 2.0 Hz) and
4.89 (ddt, J (HH) ) 19.0 Hz, J (HH) ) 3.0 Hz, J (HP) ) 1.5 Hz)
(4H, Ir-CHdCHH). 31P{1H} NMR (81 MHz, CDCl3): δ -12.55
(s, PPh3). IR (KBr, cm-1): 2109 (m, νCtC), 2026 (s, νCO). Anal.
Calcd for Ir2O2P4C92H76: C, 64.17; H, 4.45. Found: C, 63.65;
H, 4.38. MS (FAB) m/z Calcd for [M + H]+: 1722.9. Found:
1722.1 ([M + H]+).
and 137.1 (Cb and Cipso of C6H5 carbons), 129.7, 128.1 and 127.1
(CH of C6H5 carbons). HETCOR (1H (500 MHz) f 13C (125.7
MHz)): δ 6.68 f 129.5; 5.24, 5.57 f 116.1; 5.38, 5.48 f 118.3.
Electronic absorption: λmax ) 294 nm. MS m/z 156 (M+).
C6H5-HEX-d1: 1H NMR spectrum of the isotopomer C6H5-
HEX-d1 shows all the signals for C6H5-HEX except the
resonance at δ 6.68 ppm assigned to Ha of C6H5-HEX. MS m/z
157 (M+).
p-CH3C6H4-HEX: 1H NMR (500 MHz, CDCl3): δ 6.13-7.28
(AB quartet with ∆ν/J ) 4.8, 4H, J (HAHB) ) 13.5 Hz, p-C6H4-
CH3), 6.62 (br s, 1H, Ha), 6.71 (dd, J (HH) ) 17.7 Hz, J (HH) )
11.5 Hz) and 6.55 (dd, J (HH) ) 17.3 Hz, J (HH) ) 10.8 Hz)
(2H, Hc and Hc′), 5.52 (dd, J (HH) ) 17.3 Hz, J (HH) ) 2.0 Hz)
and 5.44 (dd, J (HH) ) 17.7 Hz, J (HH) ) 1.5 Hz) (2H, Hd-trans
and Hd′-trans), 5.34 (dd, J (HH) ) 11.5 Hz, J (HH) )1.5 Hz) and
5.16 (dd, J (HH) ) 10.8 Hz, J (HH) ) 2.0 Hz) (2H, Hd-cis and
(h ) P r ep a r a t ion of m ,m -C6H 3-(CtC-Ir L5)3 (8, L5
)
(-CHdCH2)2(CO)(P P h 3)2). This compound was prepared in
the same manner as described above for 7 by using 0.3 g (0.3
mmol) of 3, 0.017 g (0.11 mmol) of m,m-C6H3-(-CtCH)3 and
0.057 g (0.75 mmol) of Me3NO. The yield was 0.18 g and 71%
based on m,m-C6H3-(CtC-IrL5)3 (8, L5 ) (-CHdCH2)2(CO)-
(PPh3)2). 1H NMR (500 MHz, CDCl3): δ 7.2-7.8 (m, 93H,
P(C6H5)3 and Ir-CHdCH2), 6.53 (s, 3H, Ir-CtC-C6H3,), 6.17
(ddt, 3H, J (HH) ) 19.0 Hz, J (HH) ) 12.0 Hz, J (HP) ) 2.0 Hz,
Ir-CHdCH2), 5.93 (dd, J (HH) ) 11.5 Hz, J (HH) ) 2.0 Hz)
and 5.71 (dd, J (HH) ) 12.0 Hz, J (HH) ) 1.5 Hz) (6H, Ir-CHd
CHH), 5.25 (dd, J (HH) ) 18.0 Hz, J (HH) ) 2.0 Hz) and 4.95
(ddt, J (HH) ) 19.0 Hz, J (HH) ) 1.5 Hz) (6H, Ir-CHdCHH).
13C NMR (125.7 MHz, CDCl3): δ 174.1 (t, J (CP) ) 6.3 Hz, Ir-
CO), 143.8 (t, J (CP) ) 8.2 Hz) and 135.7 (t, J (CP) ) 12.8 Hz)
(Ir-CHdCH2), 130.4 (s, CH carbon of (Ir-CtC-)3C6H3), 124.9
and 123.0 (br s, Ir-CHdCH2), 112.9 (s, Ir-CtC), 85.8 (t, J (CP)
) 13.0 Hz, Ir-CtC). HETCOR (1H (500 MHz) f 13C (125.7
MHz)): δ 6.35 f 130.4; 6.17 f 143.8; 5.93, 5.25 f 124.9; 5.71,
4.95 f 123.0. 31P{1H} NMR (81 MHz, CDCl3): δ -12.31 (s,
PPh3). IR (KBr, cm-1): 2101 (m, νCtC), 2029 (s, νCO). Anal.
Calcd for Ir3O3P6C135H111: C, 68.95; H, 4.76. Found: C, 68.55;
H, 4.69. MS (FAB) m/z Calcd for [M + H]+: 2544.8. Found:
2545.6 ([M + H]+).
Rea ction s. (a ) Rea ction s of 2 a n d 3 w ith RCtCH(D):
Isola tion of R-HEX a n d R2-OCT (R ) C6H5 (a ), p-C6H4CH3
(b), Cycloh ex-1-en yl (c), C(CH 3)dCH2 (d ), C(CH3)3 (e)).
These reactions were carried out in the same manner as
described below for 2 with C6H5CtCH. A CHCl3 (10 mL)
solution of 2 (0.30 g, 0.3 mmol) and C6H5CtCH (0.12 g, 1.2
mmol) was stirred at 50 °C for 12 h before n-pentane (20 mL)
was added to precipitate brown microcrystals of “Ir-A” which
were removed by filtration. The filtrate was distilled at 25 °C
under vacuum to less than 1.0 mL and the residue was eluted
with n-pentane through a silica gel packed column to separate
the pale yellow oil of C6H5-HEX and (C6H5)2-OCT. The yields
were 0.15 mmol (49%) based on C6H5-HE X and 0.09 mmol
(30%) based on (C6H5)2-OCT measured by 1H NMR, respec-
tively.
H
d′-cis), 2.36 (s, 3H, p-C6H4CH3). 13C NMR (75 MHz, CDCl3):
δ 138.0 and 133.6 (s, Cc and Cc′), 118.0 and 115.7 (s, Cd and
Cd′), 129.6 (s, Ca), 21.2 (s, p-C6H4CH3), 137.2, 137.0 and 134.2
(Cb and Cipso of p-C6H4CH3 carbons), 129.6 and 128.8 (CH of
p-C6H4CH3 carbons). MS m/z 170 (M+).
1
Cyclohex-1-enyl-HEX: H NMR (300 MHz, CDCl3): δ 6.75
(dd, J (HH) ) 17.5 Hz, J (HH) ) 11.1 Hz) and 6.48 (dd, J (HH)
) 17.5 Hz, J (HH) ) 10.7 Hz) (2H, Hc and Hc′), 6.03 (br s, 1H,
Ha), 5.81 (m, 1H, CdCH-(CH2)3-CH2), 5.41 (dd, J (HH) )
17.5 Hz, J (HH) ) 1.7 Hz) and 5.31 (dd, J (HH) ) 17.5 Hz,
J (HH) ) 1.7 Hz) (2H, Hd-trans and Hd′-trans), 5.24 (dd, J (HH) )
11.1 Hz, J (HH) ) 1.7 Hz,) and 5.11 (dd, J (HH) ) 10.7 Hz,
J (HH) ) 1.7 Hz) (2H, Hd-cis and Hd′-cis), 0.8-1.2 (m, 8H,
CdCH-(CH2)3-CH2). MS m/z 160 (M+).
CH2d(CH3)C-HEX: 1H NMR (300 MHz, CDCl3): δ 6.75 (dd,
J (HH) ) 17.8 Hz, J (HH) ) 11.1 Hz) and 6.46 (dd, J (HH) )
17.3 Hz, J (HH) ) 11.0 Hz) (2H, Hc and Hc′), 6.09 (br s, 1H,
Ha), 5.44 (dd, J (HH) ) 17.3 Hz, J (HH) ) 1.8 Hz) and 5.34 (dd,
J (HH) ) 17.8 Hz, J (HH) ) 1.8 Hz) (2H, Hd-trans and Hd′-trans),
5.28 (dd, J (HH) ) 11.1 Hz, J (HH) ) 1.8 Hz) and 5.14 (dd,
J (HH) ) 11.0 Hz, J (HH) ) 1.8 Hz) (2H, Hd-cis and Hd′-cis), 5.11
and 5.00 (s, 2H,C(CH3)dCH2), 1.93 (s, 3H, C(CH3)dCH2). MS
m/z 120 (M+).
(CH3)3C-HEX: 1H NMR (300 MHz, CDCl3): δ 6.64 (ddd,
J (HH) ) 18.0 Hz, J (HH) ) 11.3 Hz, J (HH) ) 1.0 Hz) and 6.35
(ddd, J (HH) ) 17.3 Hz, J (HH) ) 10.5 Hz, J (HH) ) 1.0 Hz)
(2H, Hc and Hc′), 5.60 (br s, 1H, Ha), 5.27 (dd, J (HH) ) 11.3
Hz, J (HH) ) 2.0 Hz) and 4.98 (dd, J (HH) ) 10.5 Hz, J (HH) )
1.8 Hz) (2H, Hd-cis and Hd′-cis), 5.24 (dd, J (HH) ) 17.3 Hz,
J (HH) ) 1.8 Hz) and 5.18 (dd, J (HH) ) 18.0 Hz, J (HH) ) 2.0
Hz) (2H, Hd-trans and Hd′-trans), 1.15 (s, 9H, C(CH3)3). MS m/z
136 (M+).
(C6H5)2-OCT: 1H NMR (500 MHz, CDCl3): δ 7.1-7.6 (m,
10H, C6H5), 6.98 (dd, J (HH) ) 17.4 Hz, J (HH) ) 10.5 Hz) and
6.65 (dd, J (HH) ) 17.1 Hz, J (HH) ) 10.3 Hz) (2H, Hc and Hc′),
6.65 and 6.45 (br s, 2H, Ha and Ha′), 5.37 (dd, J (HH) ) 17.4
Hz, J (HH) ) 1.75 Hz) and 5.28 (dd, J (HH) ) 17.1 Hz, J (HH)
) 1.5 Hz) (2H, Hd-trans and Hd′-trans), 5.20 (dd, J (HH) ) 10.5
Hz, J (HH) ) 1.75 Hz) and 5.16 (dd, J (HH) ) 10.3 Hz, J (HH)
) 1.5 Hz) (2H, Hd-cis and Hd′-cis). 13C NMR (125.7 MHz,
CDCl3): δ 140.5 and 132.0 (s, Cc and Cc′), 132.0 and 131.8 (s,
Ca and Ca′), 118.4 and 115.6 (s, Cd and Cd′). HETCOR (1H (500
MHz) f 13C (125.7 MHz)): δ 6.98 f 132.0; 6.65 f 140.5; 6.65
f 131.8; 6.45 f 132.0; 5.37, 5.20 f 118.4; 5.28, 5.16 f 115.6.
MS m/z 258 (M+).
The reaction of 3 (0.30 g, 0.3 mmol) with C6H5CtCH (0.092
g, 0.9 mmol) gave brown microcrystals of “Ir-B” which were
removed by filtration and C6H5-HEX of which the yield was
0.26 mmol and 87% based on C6H5-HEX measured by 1H
NMR.
C6H5-HEX: 1H NMR (500 MHz, CDCl3): δ 7.2-7.5 (m, 5H,
C6H5), 6.68 (br s, 1H, Ha), 6.74 (dd, J (HH) ) 17.7 Hz, J (HH)
) 11.3 Hz) and 6.59 (dd, J (HH) ) 17.3 Hz, J (HH) ) 10.5 Hz)
(2H, Hc and Hc′), 5.57 (dd, J (HH) ) 17.3 Hz, J (HH) ) 1.5 Hz)
and 5.48 (dd, J (HH) ) 17.7 Hz, J (HH) ) 1.5 Hz) (2H, Hd-trans
and Hd′-trans), 5.38 (dd, J (HH) ) 11.3 Hz, J (HH) ) 1.5 Hz) and
5.24 (dd, J (HH) ) 10.5 Hz, J (HH) ) 1.5 Hz) (2H, Hd-cis and
(C6H5)2-OCT-d2. 1H NMR spectrum of the isotopomer (C6H5)2-
OCT-d2 shows all the signals for (C6H5)2-OCT except the
resonance at δ 6.65 and 6.45 ppm assigned to Ha and Ha′ of
(C6H5)2-OCT. MS m/z 260 (M+).
(p-CH3-C6H4)2-OCT: 1H NMR (300 MHz, CDCl3): δ 7.1-
7.6 (m, 8H, p-C6H4CH3), 7.00 (dd, J (HH) ) 16.8 Hz, J (HH) )
10.2 Hz) and 6.64 (dd, J (HH) ) 17.1 Hz, J (HH) ) 10.5 Hz)
(2H, Hc and Hc′), 6.62 and 6.43 (br s, 2H, Ha and Ha′), 5.35 (d,
H
d′-cis). 13C NMR (125.7 MHz, CDCl3): δ 137.8 and 133.5 (s,
Cc and Cc′), 129.5 (s, Ca), 118.3 and 116.1 (s, Cd and Cd′), 137.9

Synthesis of Cross-Conjugated Olefins from Alkynes
Organometallics, Vol. 21, No. 19, 2002 3895
J (HH) ) 16.8 Hz) and 5.26 (d, J (HH) ) 17.1 Hz) (2H, Hd-trans
and Hd′-trans), 5.18 (d, J (HH) ) 10.2 Hz) and 5.13 (d, J (HH) )
10.5 Hz) (2H, Hd-cis and Hd′-cis), 2.40 and 2.31(s, 6H, C6H5CH3).
MS m/z 286 (M+).
s, Cd), 21.1 (s, p-C6H4CH3). HETCOR (1H (500 MHz) f 13C
(125.7 MHz)): δ 6.83 f 128.9; 5.86, 5.73 f 124.5; 5.59 f 85.5;
2.37 f 21.1; 1.37 f 61.9; 2.43, 0.25 f 39.3. 31P{1H} NMR (81
MHz, CDCl3): δ 1.48 (d, J (PP) ) 10.8 Hz, PPh3), -5.94
(d, J (PP) ) 10.8 Hz, PPh3). IR (KBr, cm-1): 2019 (s, νCO),
1062 (s, due to uncoordinated BF4-). Anal. Calcd for IrBF4-
OP2C50H44: C, 59.94; H, 4.43. Found: C, 60.26; H, 4.51.
[Ir(η4-cyclohex-1-enyl-HEX)(CO)(PPh3)2]BF4 (5c): 1H NMR
(500 MHz, CDCl3): δ 6.9-7.5 (m, 30H, P(C6H5)3), 6.58
(dd, 1H, J (HH) ) 17.5 Hz, J (HH) ) 10.9 Hz, He), 5.96 (d, 1H,
J (HH) ) 17.5 Hz, Hf-trans), 5.77 (d, 1H, J (HH) ) 10.9 Hz, Hf-cis),
Detailed spectral data for (cyclohex-1-enyl)2-OCT, (CH2d
(CH3)C)2-OCT, and ((CH3)3C)2-OCT are not given here since
we have not been able to obtain a large enough amount of these
R2-OCT in high purity to measure the detailed spectra. GC/
mass spectra, however, unambiguously confirm (cyclohex-1-
enyl)2-OCT (m/z 266 (M+)), (CH2d(CH3)C)2-OCT (m/z 186
(M+)), and ((CH3)3C)2-OCT (m/z 218 (M+)).
5.62 (m, 1H, Hc), 5.17 (br s, 1H, Ir(η4-(CH2(CH2)3CHdC)-
HEX), 2.55 (quartetlike, 1H, Hd-cis), 1.4-2.0 (m, 8H, Ir(η4-
(b) Rea ction s of “Ir -A” a n d “Ir -B” w ith H2. Both
reactions were carried out in the same manner as described
below for the reaction of “Ir-A” with H2. A CHCl3 (10 mL)
solution of “Ir-A” (0.05 g) was stirred under H2 (3 atm) at 25
°C for 24 h in a bomb reactor before n-pentane (10 mL) was
added to precipitate beige microcrystals of [Ir(H)2(NCCH3)2-
(PPh3)2]OTf (1) which were collected by filtration, washed with
n-pentane (3 × 10 mL), and dried under vacuum. The yield
was 0.045 g. [Ir(H)2(CO)2(PPh3)2]OTf (1′): 1H NMR (300 MHz,
CDCl3): δ 7.4-7.7 (m, 30H, P(C6H5)3), -9.91 (t, 2H, J (HP) )
14.4 Hz, Ir-H).13C NMR (75.5 MHz, CDCl3): δ 170.4 (t, J (CP)
) 11.8 Hz, Ir-CO), 133.5, 132.7, 130.1 and 129.7 (P(C6H5)3).31P-
{1H} NMR (81 MHz, CDCl3): δ -16.3 (s, PPh3). IR (KBr, cm-1):
2148 (w, νIr-H), 2022, 2002 (s, νCO), 1270, 1151 and 1034 (s,
due to uncoordinated OTf).
(CH2(CH2)3CHdC)-HEX), 0.61 (t, 1H, J (HP) ) 9.5 Hz, J (HH)
) 9.5 Hz, Ha), 0.04 (m, 1H, Hd-trans).13C NMR (125.7 MHz,
CDCl3): δ 172.0 (d, J (CP) ) 11.7 Hz, Ir-CO), 133.7 (d, J (CP)
) 2.7 Hz, Ir(η4-(CH2(CH2)3CHdC)-HEX)), 130.8 (d, J (CP) )
3.1 Hz, Ir(η4-(CH2(CH2)3CHdC)-HEX)), 129.4 (d, J (CP) ) 2.4
Hz, Ce), 123.3 (br s, Cf), 107.3 (t, J (CP) ) 3.7 Hz, Cb), 84.2 (br
s, Cc), 69.2 (d, J (CP) ) 34.8 Hz, Ca), 38.5 (br s, Cd), 30.7 (d,
J (CP) ) 4.9 Hz, Ir(η4-(CH2(CH2)3-CHdC)-HEX)), 25.6, 22.9,
and 21.6 (s, Ir(η4-(CH2(CH2)3-CHdC)-HEX)), 133.2, 133.1,
131.6, 131.4, 130.5, 130.1, 129.0 and 128.5 (P(C6H5)3). HET-
COR (1H (500 MHz) f 13C (125.7 MHz)): δ 6.58 f 129.4; 5.96,
5.77 f 123.3; 5.62 f 84.2; 5.17 f 130.8; 0.61 f 69.2; 2.55,
0.04 f 38.5. 31P{1H} NMR (81 MHz, CDCl3): δ 5.71 (d, J (P-
P) ) 10.3 Hz, PPh3), -7.76 (d, J (P-P) ) 10.3 Hz, PPh3). IR
(KBr, cm-1): 2011 (s, νCO), 1063 (s, due to uncoordinated BF4-).
Anal. Calcd for IrBF4OP2C49H46: C, 59.34, H, 4.67. Found: C,
59.62; H, 4.74. 1H NMR spectrum of 5c shows the four terminal
olefinic protons of the two -CHdCH2 groups at δ 5.77 (Hf-cis),
5.96 (Hf-trans), 0.04 (Hd-trans), and 2.55 (Hd-cis). The large
separation between the two groups (Hd at δ 0.04-2.55 and Hf
at δ 5.77-5.96) strongly suggests that these two groups are
very much different in interaction with the central metal
suggesting one -CHdCH2 group (Hd-cis and Hd-trans) being
coordinated to the metal and the other (Hf-cis and Hf-trans) being
free from the metal as shown by 5c. The larger NOE enhance-
ment between Hc and Hf-trans (4.50%) and the smaller one
between Hc and He (0.86%) on irradiation at Hc (δ 5.70)
resonance of 5c also strongly suggest a shorter distance
between Hc and Hf-trans than the one between Hc and He.
(c) Rea ction s of Ir (-CtCR)(-CHdCH2)2(CO)(P P h 3)2
(4, R ) C6H5 (a ), p-CH3C6H4 (b), cycloh ex-1-en yl (c)) w ith
HBF 4: F or m a t ion of [Ir (η4-R -HE X)(CO)(P P h 3)2]BF 4 (5)
a n d Deta iled NMR Sp ectr a l Da ta An a lysis for 5c. These
reactions were carried out in the same manner as described
below for the reaction of 4a . A reaction mixture of 4a (0.10 g,
0.1 mmol) and HBF4 (8.4 µL, 54 wt % in Et2O) in CHCl3 (10
mL) was stirred for 1 h at 25 °C before Et2O (30 mL) was added
to precipitate beige microcrystals which were collected by
filtration, washed with n-pentane (3 × 10 mL), and dried under
vacuum. The yield was 0.092 g and 93% based on [Ir(η4-C6H5-
HEX)(CO)(PPh3)2]BF4 (5a ).
(d ) Rea ction s of Ir (-CtCR)(-CHdCH2)2(CO)(P P h 3)2
(4, R ) C6H5 (a ), p-CH3C6H4 (b), cycloh ex-1-en yl (c)) w ith
DBF 4: F or m a tion of [Ir (η4-R-HEX-d 1)(CO)(P P h 3)2]BF 4 (5-
d 1). Reactions with deutrated acid, DBF4, were carried out in
1H NMR (500 MHz, CDCl3): δ 6.8-7.5 (m, 36H, P(C6H5)3,
C6H5 and He), 5.87 (d, 1H, J (HH) ) 17.5 Hz, Hf-trans), 5.74 (d,
1H, J (HH) ) 11.0 Hz, Hf-cis), 5.61 (m, 1H, Hc), 2.44 (quartet-
like, 1H, Hd-cis), 1.37 (dd, 1H, J (HP) ) 11.3, 9.0 Hz, Ha), 0.29
(m, 1H, Hd-trans). 13C NMR (125.7 MHz, CDCl3): δ 172.5 (dd,
J (CP) ) 12.8 Hz, Ir-CO), 130.3 (br s, Ce), 124.7 (br s, Cf), 106.2
(br s, Cb), 85.5 (br s, Cc), 61.5 (d, J (CP) ) 31.7 Hz, Ca), 39.3 (br
s, Cd). HETCOR (1H (500 MHz) f 13C (125.7 MHz)): δ 5.87,
5.74 f 124.7; 5.61 f 85.5; 1.37 f 61.5; 2.44, 0.29 f 39.2. 31P-
{1H} NMR (81 MHz, CDCl3): δ 1.55 (d, J (PP) ) 11.3 Hz, PPh3),
-6.00 (d, J (PP) ) 11.3 Hz, PPh3). IR (KBr, cm-1): 2019 (s,
1
the same manner as described above for that of 4a . H NMR
spectra of the isotopomer [Ir(η4-R-HEX-d1)(CO)(PPh3)2]BF4 (5-
d1) show all the signals for 5 except the resonance assigned to
Ha of 5.
(e) Rea ction s of [Ir (η4-R-HEX)(CO)(P P h 3)2]BF 4 (5, R )
C6H5 (a ), p-CH3C6H4 (b), cycloh ex-1-en yl (c)) w ith Et4NCl,
CH3CN, or P P h 3. These reactions were carried out in a
similar manner as described below for the reaction of 5a with
Et4NCl. A light brown solution of 5a (0.1 mmol) and Et4NCl
(0.025 g, 0.15 mmol) in CHCl3 (10 mL) was stirred at 25 °C
under N2 for 1 h before excess Et4NCl was removed by
extraction with H2O (2 × 10 mL). Addition of n-pentane (30
ν
CO), 1057 (s, due to uncoordinated BF4-). Anal. Calcd for
IrBF4OP2C49H42: C, 59.58; H, 4.29. Found: C, 59.87; H, 4.41.
[Ir(η4-p-C6H4CH3-HEX)(CO)(PPh3)2]BF4 (5b): 1H NMR (500
MHz, CDCl3): δ 6.8-7.5 (m, 34H, P(C6H5)3 and p-C6H4CH3),
6.83 (dd, 1H, J (HH) ) 17.3 Hz, J (HH) ) 10.7 Hz, He), 5.86 (d,
1H, J (HH) ) 17.3 Hz, Hf-trans), 5.73 (d, 1H, J (HH) ) 10.7 Hz,
Hf-cis), 5.59 (m, 1H, Hc), 2.43 (quartetlike, 1H, Hd-cis), 2.37 (s,
3H, CH3), 1.37 (dd, 1H, J (HP) ) 11.0 and 8.8 Hz, Ha), δ 0.25
(m, 1H, Hd-trans). 13C NMR (125.7 MHz, CDCl3): δ 172.2 (d,
J (CP) ) 10.5 Hz, Ir-CO), 128.9 (br s, Ce), 124.5 (br s, Cf), 106.1
(br s, Cb), 85.5 (br s, Cc), 61.9 (d, J (CP) ) 31.6 Hz, Ca), 39.3 (br
12
mL) resulted in yellow microcrystals of IrCl(CO)(PPh3)2
which were removed by filtration. The filtrate was concen-
trated to less than 1.0 mL by distillation at 25 °C under
vacuum and the residue was eluted through a silica gel column
with n-hexane to obtain C6H5-HEX. The yield was 0.089 mmol
1
and 89% based on C6H5-HEX measured by H NMR.
(12) (a) Vaska, L. J . Am. Chem. Soc. 1966, 88, 4100. (b) Inorg. Synth.
1968, 11, 101.

3896 Organometallics, Vol. 21, No. 19, 2002
Chin et al.
IrCl(CO)(PPh3)2, [Ir(NCCH3)(CO)(PPh3)2]BF4,13 and [Ir(CO)-
Ta ble 2. Deta ils of Cr ysta llogr a p h ic Da ta
Collection for 4ca
14
(PPh3)3]BF4 obtained from the reactions of 5 with Et4NCl,
CH3CN, or PPh3, respectively, have been identified by 1H NMR
and IR spectral measurements.
chemical formula
fw
C49H45IrOP2
903.99
(f) Rea ction s of 7 a n d 8 w ith HBF 4 follow ed by
Tr ea tm en t w ith Et4NCl, CH3CN, or P P h 3: Isola tion of
p-C6H4-(HEX)2 a n d m ,m -C6H3-(HEX)3. These reactions were
carried out in the same manner as described above for those
of 4 with HBF4 and of 5 with Et4NCl, CH3CN, or PPh3. The
yields of light yellow microcrystals of p-C6H4-(HEX)2 and
yellow oil of m,m-C6H3-(HEX)3 were ca. 79% based on p-C6H4-
(HEX)2 and ca. 81% based on m,m-C6H3-(HEX)3 measured by
1H NMR, respectively.
temp, K
cryst size, mm3
cryst system
space group
color of crystal
a, Å
293(2)
0.8 × 0.3 × 0.2
monoclinic
P21/n
yellow
10.1830(10)
18.715(2)
21.413(4)
90.00
95.110(10)
90.00
4064.6(10)
4
1.477
3.400
1816
Mo ΚR
0.7107
b, Å
c, Å
R, deg.
â, deg.
p-C6H4-(HEX)2: 1H NMR (500 MHz, CDCl3): δ 7.35 (s, 4H,
C6H4), 6.62 (br s, 2H, Ha), 6.73 (dd, J (HH) ) 17.8 Hz, J (HH)
) 11.0 Hz) and 6.56 (dd, J (HH) ) 17.3 Hz, J (HH) ) 10.8 Hz)
(4H, Hc and Hc′), 5.55 (dd, J (HH) ) 17.3 Hz, J (HH) ) 1.5 Hz)
and 5.48 (dd, J (HH) ) 17.8 Hz, J (HH) ) 1.5 Hz) (4H, Hd-trans
and Hd′-trans), 5.39 (dd, J (HH) ) 11.0 Hz, J (HH) ) 1.5 Hz) and
5.22 (dd, J (HH) ) 10.8 Hz, J (HH) ) 1.5 Hz) (4H, Hd-cis and
γ, deg.
V, Å3
Z
F
(calc), g cm-1
µ, mm-1
F(000)
radiation
wavelength
2θ max, deg
hkl range
H
d′-cis). 13C NMR (125.7 MHz, CDCl3): δ 138.0 and 133.5 (s,
50
Cc and Cc′), 129.2 (s, Ca), 118.6 and 116.1 (s, Cd and Cd′), 138.0
and 136.0 (Cb and Cipso of C6H4 carbons), 129.5 (CH of C6H4
carbons). Mp 48-49 °C. Electronic absorption: λmax ) 333 nm.
MS m/z 234 (M+).
-10 e h e 10
-1 e k e 19
-22 e l e 22
4949
4319
3849
478
ω/2θ scan
0.0486
no. of reflcns
no. of unique data
1
m,m-C6H3-(HEX)3: H NMR (500 MHz, CDCl3): δ 7.25 (s,
no. of obsd (|Fo| > 2σ Fo) data
3H, C6H3), 6.62 (br s, 3H, Ha), 6.72 (dd, J (HH) ) 17.8 Hz,
J (HH) ) 11.5 Hz) and 6.56 (dd, J (HH) ) 17.1 Hz, J (HH) )
10.5 Hz) (6H, Hc and Hc′), 5.56 (dd, J (HH) ) 17.1 Hz, J (HH)
) 1.5 Hz) and 5.47 (dd, J (HH) ) 17.8 Hz, J (HH) ) 1.5 Hz)
(6H, Hd-trans and Hd′-trans), 5.39 (dd, J (HH) ) 11.5 Hz, J (HH)
) 1.5 Hz) and 5.23 (dd, J (HH) ) 10.5 Hz, J (HH) ) 1.5 Hz)
(6H, Hd-cis and Hd′-cis). 13C NMR (125.7 MHz, CDCl3): δ 137.8
and 133.4 (s, Cc and Cc′), 129.8 (s, Ca), 118.6 and 116.3 (s, Cd
and Cd′), 138.3 and 136.7 (Cb and Cipso of C6H3 carbons), 129.2
(CH of C6H3 carbons). Electronic absorption: λmax ) 303 nm.
MS m/z 312 (M+).
X-r a y Str u ctu r e Deter m in a tion of Ir (-CtC-cycloh ex-
1-en yl)(-CHdCH2)2(CO)(P P h 3)2 (4c). Crystals were grown
from CHCl3. Diffraction data were collected on an Enraf-
Nonius CAD4 diffractometer with graphite-monochromated
Mo KR radiation at 20 °C. Accurate cell parameters were
determined from the least-squares fit of 24 accurately centered
reflections in each selected range. All data were collected with
the ω/ 2θ scan modes, and corrected Lp effects and absorption.
The structures of these compounds were solved by Patterson’s
heavy atom methods (SHELXS-97). Details of crystallographic
data collection are listed in Table 2. Bond distances and angles,
positional and thermal parameters, and anisotropic thermal
parameters have been included in the tables of Supporting
Information. The non-hydrogen atom was refined by full-
matrix least-squares techniques (SHELXL-97). 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 isotro-
no. of parameters
scan type
R1
wR2
0.1578
1.132
GOF
R1 ) [∑|Fo| - |Fc|/|Fo|], wR2 ) [∑w(Fo - Fc2)2/∑w (Fo2)2]0.5, w
a
2
2
2
) 1/[σ2Fo + (0.0865P)2 + 28.8775P], where P ) (Fo + 2Fc2)/3.
pic thermal parameters. The final R1 and wR2 (R1 ) [∑|Fo| -
|Fc|/|Fo| and wR2 ) [∑w(Fo - Fc2)2/∑w(Fo2)2]0.5) values were
2
0.0486 and 0.1578.
Ack n ow led gm en t. The authors wish to thank Prof.
Y. J . Park, Sookmyung Women’s University, for X-ray
crystal analysis and the Korea Science and Engineering
Foundation (Grant No. R01-2000-00044) for the finan-
cial support of this study.
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 complex 4c in CIF format
and 1H NMR (for 2, 2-d2, 4c, 5c, 6a , 7, 8, C6H5-HEX, C6H5-
HEX-d1, (C6H5)2-OCT, (C6H5)2-OCT-d2, p-C6H4-(HEX)2, and
m,m-C6H3-(HEX)3), 13C NMR (for 2, 4c, 5c, and 6a ), H NOE
1
(for 5c), 1H,13C-2D HETCOR (for 2, 5c, and 6a ), GC/mass (for
C6H5-H E X, C6H5-H E X-d1, (C6H5)2-OCT, (C6H5)2-OCT-d2,
p-C6H4-(HEX)2, and m,m-C6H3-(HEX)3), and FAB mass (for 7
and 8) data. This material is available free of charge via the
Internet at http://pubs.acs.org.
(13) Reed, C. A.; Roper, W. R. J . Chem. Soc., Dalton Trans. 1973,
1365.
(14) Peone, J ., J r.; Vaska, L. Angew. Chem., Int. Ed. Engl. 1971,
10, 551.
OM020410R