Iridium complex-catalyzed allylic alkylation of allylic esters and allylic alcohols: Unique regio- and stereoselectivity

Article abstract of DOI:10.1021/ja981560p

An iridium complex was found to be an efficient catalyst for allylic alkylation of allylic esters with a stabilized carbon nucleophile. Highly regioselective alkylation at the substituted allylic terminus was achieved. The catalytic activity and regioselectivity were affected by the ligand used. The reaction of (E)-2-alkenyl acetates or 1-substituted 2-propeny acetates with dialkyl sodiomalonate in the presence of a catalytic amount of [Ir(COD)Cl]₂/P(OPh)₃ (P/Ir = 1-2) gave a product alkylated at the substituted allylic terminus in 95-99% selectivity. Construction of a quaternary carbon center is possible by this methodology. The reaction of 1,1-dialkyl-2-propenyl acetates gave a product alkylated at the disubstituted allylic terminus exclusively. (E)-2-Alken-1-ol could be successfully used as a substrate. The products alkylated at the substituted allylic terminus were obtained in 93-99% selectivity. A ³¹P NMR study of the reaction of [Ir(COD)Cl]₂ with P(OPh)₃ revealed that a catalytically active species is a monophosphite species. The π-acceptor property of P(OPh)₃ promotes a carbonium ion character at the substituted allylic terminus and directs the nucleophilic attack to this position. The stereochemistry of the allyl system affected the regioselectivity. In contrast to the reaction of (E)-2-alkenyl acetates, the reaction of (Z)-2-alkenyl acetates gave a product alkylated at the unsubstituted allylic terminus predominantly. This shows that the regioselectivity of the alkylation of the syn π-allyl iridium intermediate is different from that of the anti π-allyl iridium intermediate. (Z)- Selective allylic alkylation of (Z)-2-alkenyl esters is also possible by iridium catalysis.

Full text of DOI:10.1021/ja981560p

J. Am. Chem. Soc. 1998, 120, 8647-8655
8647
Iridium Complex-Catalyzed Allylic Alkylation of Allylic Esters and
Allylic Alcohols: Unique Regio- and Stereoselectivity
Ryo Takeuchi* and Mikihiro Kashio
Contribution from the Department of EnVironmental Science, Faculty of Science and Graduate School of
Integrated Science, Yokohama City UniVersity, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan
ReceiVed May 5, 1998
Abstract: An iridium complex was found to be an efficient catalyst for allylic alkylation of allylic esters with
a stabilized carbon nucleophile. Highly regioselective alkylation at the substituted allylic terminus was achieved.
The catalytic activity and regioselectivity were affected by the ligand used. The reaction of (E)-2-alkenyl
acetates or 1-substituted 2-propeny acetates with dialkyl sodiomalonate in the presence of a catalytic amount
of [Ir(COD)Cl]2/P(OPh)3 (P/Ir ) 1-2) gave a product alkylated at the substituted allylic terminus in 95-99%
selectivity. Construction of a quaternary carbon center is possible by this methodology. The reaction of
1,1-dialkyl-2-propenyl acetates gave a product alkylated at the disubstituted allylic terminus exclusively. (E)-
2-Alken-1-ol could be successfully used as a substrate. The products alkylated at the substituted allylic terminus
were obtained in 93-99% selectivity. A 31P NMR study of the reaction of [Ir(COD)Cl]2 with P(OPh)3 revealed
that a catalytically active species is a monophosphite species. The π-acceptor property of P(OPh)3 promotes
a carbonium ion character at the substituted allylic terminus and directs the nucleophilic attack to this position.
The stereochemistry of the allyl system affected the regioselectivity. In contrast to the reaction of (E)-2-
alkenyl acetates, the reaction of (Z)-2-alkenyl acetates gave a product alkylated at the unsubstituted allylic
terminus predominantly. This shows that the regioselectivity of the alkylation of the syn π-allyl iridium
intermediate is different from that of the anti π-allyl iridium intermediate. (Z)-Selective allylic alkylation of
(Z)-2-alkenyl esters is also possible by iridium catalysis.
Introduction
as catalysts or reagents for allylic alkylation. The control of
regioselectivity in allylic alkylation is important. The selectivity
depends on many factors, for example, the central metal, ligand,
nucleophile, and substituent on the π-allyl system. Terminally
monosubstituted palladium complexes generally lead to pref-
erential alkylation at the unsubstituted allylic terminus14 while
such molybdenum,10a,b,f,g,i-k,m tungsten,12a-c,f,g and ruthenium13b
complexes tend to lead to preferential alkylation at the substi-
tuted allylic terminus. Gaining complete regiocontrol of alky-
lation at the substituted allylic terminus is a challenging problem.
We wish to report herein iridium complex-catalyzed highly
Transition metal complexes are indispensable tools for organic
synthesis. Many useful organic transformations have been
achieved. A wide variety of transition metal complexes are
extensively studied as reagents or catalysts for organic synthe-
sis.1 The use of iridium complexes for organic synthesis is
relatively unexplored. Since Crabtree reported that a cationic
iridium complex is a highly active catalyst for hydrogenation
of highly hindered alkenes such as 2,3-dimethyl-2-butene2
iridium complexes have received much attention as efficient
hydrogenation catalysts.3 Iridium complex-catalyzed hydrosi-
lylations have also been reported.4 On the other hand, the
development of iridium complex-catalyzed carbon-carbon bond
forming reactions lags far behind.5 A limited number of
synthetically useful stereo- and regiocontrolled carbon-carbon
bond forming reactions are reported.6
(3) (a) Schnider, P.; Koch, G.; Pretot, R.; Wang, G.; Bohnen, F. M.;
Kruger, C.; Pfaltz, A. Chem.sEur. J. 1997, 3, 887. (b) Bedford, R. B.;
Castillon, S.; Chaloner, P. A.; Claver, C.; Fernandez, E.; Hitchcock, P. B.;
Ruiz, A. Organometallics 1996, 15, 3990. (c) Tani, K.; Onouchi, J.;
Yamagata, T.; Kataoka, Y. Chem. Lett. 1995, 955. (d) Zhang, X.; Taketomi,
T.; Yoshizumi, T.; Kumobayashi, H.; Akutagawa, S.; Mashima, K.; Takaya,
H. J. Am. Chem. Soc. 1993, 115, 3318. (e) Esteruelas, M. A.; Lopez, A.
M.; Oro, L. A.; Perez, A.; Schultz, M.; Werner, H. Organometallics 1993,
12, 1823. (f) Mashima, K.; Akutagawa, T.; Zhang, X.; Takaya, H. J.
Organomet. Chem. 1992, 428, 213. (g) Chan, Y. Ng. C.; Osborn, J. A. J.
Am. Chem. Soc. 1990, 112, 9400. (h) Spindler, F.; Pugin, B.; Blaser, H. U.
Angew. Chem., Int. Ed. Engl. 1990, 29, 558. (i) Oro, L. A.; Cabeza, J. A.;
Cativiela, C.; Diaz de Villegas, M. D.; Malendez, E. J. Chem. Soc., Chem.
Commun. 1983, 1383. (j) Stork, G.; Kahne, D. E. J. Am. Chem. Soc. 1983,
105, 1072. (k) Crabtree, R. H.; Demou, P. C.; Eden, D.; Mihelcic, J. M.;
Parnell, C. A.; Quirk, J. M.; Morris, G. E. J. Am. Chem. Soc. 1982, 104,
6994.
(4) (a) Esteruelas, M. A.; Olivan, M.; Oro, L. A.; Tolosa, J. I. J.
Organomet. Chem. 1995, 487, 143. (b) Jun, C.-H.; Crabtree, R. H. J.
Organomet. Chem. 1993, 447, 177. (c) Esteruelas, M. A.; Nurnberg, O.;
Olivan, M.; Oro, L. A.; Werner, H. Organometallics 1993, 12, 3264. (d)
Tanke, R. S.; Crabtree, R. H. Organometallics 1991, 10, 415. (e) Tanke,
R. S.; Crabtree, R. H. J. Am. Chem. Soc. 1990, 112, 7984. (f) Fernandez,
M. J.; Esteruelas, M. A.; Jimenez, M. S.; Oro, L. A. Organometallics 1986,
5, 1519.
One of the important carbon-carbon bond forming reactions
catalyzed by a transition metal complex is allylic alkylation via
a π-allyl complex, which is widely used for constructing
complex organic molecules.7 Palladium,8 nickel,9 molybde-
num,10 iron,11 tungsten,12 and ruthenium13 complexes are used
(1) (a) Gibson, S. E. Transition Metals in Organic Synthesis: A Practical
Approach; Oxford University Press: Oxford, 1997. (b) Hegedus, L. S. In
ComprehensiVe Organometallic Chemistry II; Abel, E. W., Stone, F. G.
A., Wilkinson, G., Eds.; Pergamon: Oxford, 1995; Vol. 12. (c) Hegedus,
L. S. Transition Metals in the Synthesis of Complex Organic Molecules;
University Science Books: Mill Valley, 1994. (d) McQuillin, F. J.; Parker,
D. G.; Stephenson, G. R. Transition Metal Organometallics for Organic
Synthesis; Cambridge University Press: Cambridge, 1991. (e) Harrington,
P. J. Transition Metals in Total Synthesis: John Wiley & Sons: New York,
1990.
(2) (a) Crabtree, R. H. Acc. Chem. Res. 1979, 12, 331. (b) Crabtree, R.
H.; Felkin, H.; Morris, G. E. J. Organomet. Chem. 1977, 141, 205.
S0002-7863(98)01560-1 CCC: $15.00 © 1998 American Chemical Society
Published on Web 08/15/1998

8648 J. Am. Chem. Soc., Vol. 120, No. 34, 1998
Takeuchi and Kashio
Table 1. Effect of Ligand on Allylic Alkylation of 1 with 2aa
entry
substrate
ligand
P/Ir
conditions
yield/%b
ratio 3/4 (E/Z)c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1a
1a
1a
1a
1b
1c
1a
1a
1a
1a
1a
1a
1a
1a
1a
0
1
2
3
2
2
2
2
2
2
2
2
2
2
2
reflux 19 h
66
90
89
29
94
85
81
55
64
52
81
44
6
12/88 (97/3)
96/4 (78/22)
96/4 (81/19)
76/24 (96/4)
97/3 (77/23)
89/11 (90/10)
95/5 (73/27)
94/6 (94/6)
P(OPh)3
P(OPh)3
P(OPh)3
P(OPh)3
room temp 3 h
room temp 3 h
reflux 24 h
room temp 1 h
room temp 4 h
room temp 8 h
room temp 23 h
room temp 18 h
room temp 16 h
reflux 3 h
reflux 3 h
reflux 16 h
reflux 16 h
reflux 16 h
P(OPh)3
P(O4-MeC6H4)3
P(O4-FC6H4)3
P(O2-Naph)3
PPh(OPh)2
P(OEt)3
P(Oi-Pr)3
PPh3
96/4 (92/8)
98/2 (75/25)
59/41 (90/10)
53/47 (91/9)
24/76 (63/37)
P(n-Bu)3
dppe
0
18
39/61 (94/6)
a A mixture of 1 (2 mmol), 2 (4 mmol), [Ir(COD)Cl]2 (0.04 mmol), ligand, and THF (10 mL) was stirred under argon. b Isolated yield. c Determined
by GLC.
regioselective allylic alkylation at the substituted allylic terminus
the most efficient ligand (entries 2 and 3). The reaction was
completed in 3 h at room temperature to give an excellent yield
of the products. Product 3a was obtained in 96% selectivity
(entry 3). The alkylation was highly selective at the substituted
allylic terminus. The ratio of P(OPh)3 to Ir was also important.
When using 1 equiv of P(OPh)3 to each equivalent of Ir, 3a
was obtained in 96% selectivity and the reaction proceeded at
with a stabilized carbon nucleophile.15
Results
Allylic Alkylation of (E)-Allylic Esters and 1-Substituted
2-Propenyl Esters. The reaction of (E)-2-hexenyl acetate (1a)
with diethyl sodiomalonate (2a) in the presence of a catalytic
amount of [Ir(COD)Cl]2 and ligand gave 3a, (E)-4a, and (Z)-
4a. Product 3a arose from alkylation at the substituted allylic
terminus, and 4a arose from alkylation at the unsubstituted
allylic terminus (eq 1). The phosphorus ligand that was added
(9) (a) Nomura, N.; RajanBabu, T. V. Tetrahedron Lett. 1997, 38, 1713.
(b) Kobayashi, Y.; Mizojiri, R.; Ikeda, E. J. Org. Chem. 1996, 61, 5391.
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6105. (d) Mizoziri, R.; Kobayashi, Y. J. Chem. Soc., Perkin Trans. 1 1995,
2073. (e) Bricout, H.; Carpentier, J. F.; Mortreux, A. J. Chem. Soc., Chem.
Commun. 1995, 1863. (f) Trost, B. M.; Spagnol, M. D. J. Chem. Soc., Perkin
Trans. 1 1995, 2083. (g) Consiglio, G.; Indolese, A. Organometallics 1994,
13, 2230. (h) Consiglio, G.; Indolese, A. Organometallics 1991, 10, 3425.
(i) Alvarez, E.; Cuvigny, T.; Julia, M. J. Organomet. Chem. 1988, 339,
199. (j) Cuvigny, T.; Julia, M. J. Organomet. Chem. 1986, 317, 383. (k)
Minami, I.; Shimizu, I.; Tsuji, J. J. Organomet. Chem. 1985, 296, 269.
(10) (a) Trost, B. M.; Hachiya, I. J. Am. Chem. Soc. 1998, 120, 1104.
(b) Sjogren, M. P. T.; Frisell, H.; Akermark, B.; Norrby, P.-O.; Eriksson,
L.; Vintagliano, A. Organometallics 1997, 16, 942. (c) Dvorak, D.; Stary,
I.; Kocovsky, P. J. Am. Chem. Soc. 1995, 117, 6130. (d) Dvorakova, H.;
Dovorak, D.; Srogl, J.; Kocovsky, P. Tetrahedron Lett. 1995, 36, 6351. (e)
Yu, R. H.; McCallum, J. S.; Liebeskind, L. S. Organometallics 1994, 13,
1476. (f) Trost, B. M.; Merlic, C. A. J. Am. Chem. Soc. 1990, 112, 9590.
(g) Trost, B. M.; Merlic, C. A. J. Org. Chem. 1990, 55, 1127. (h) Faller, J.
W.; Linebarrier, D. Organometallics 1988, 7, 1670. (i) Trost, B. M.; Lautens,
M. Tetrahedron 1987, 43, 4817. (j) Trost, B. M.; Lautens, M. J. Am. Chem.
Soc. 1987, 109, 1469. (k) Trost, B. M.; Lautens, M. J. Am. Chem. Soc.
1983, 105, 3343. (l) Trost, B. M.; Lautens, M. Organometallics 1983, 2,
1687. (m) Trost, B. M.; Lautens, M. J. Am. Chem. Soc. 1982, 104, 5543.
(11) (a) Enders, D.; Jandeleit, B.; Raabe, G. Angew. Chem., Int. Ed. Engl.
1994, 33, 1949. (b) Green, J. R.; Carroll, M. K. Tetrahedron Lett. 1991,
32, 1141. (c) Xu, Y.; Zhou, B. J. Org. Chem. 1987, 52, 974. (d) Silverman,
G. S.; Strickland, S.; Nicholas, K. M. Organometallics 1986, 5, 2117. (e)
Roustan, J. L.; Merour, J. Y.; Houlihan, F. Tetrahedron Lett. 1979, 3721.
(f) Roustan, J. L.; Houlihan, F. Can. J. Chem. 1979, 57, 2790.
(12) (a) Lloyd-Jones, G. C.; Pfaltz, A. Angew. Chem., Int. Ed. Engl. 1995,
34, 462. (b) Lloyd-Jones, G. C.; Pfaltz, A. Z. Naturforsch. 1995, 50b, 361.
(c) Lehman, J.; Lloyd-Jones, G. C. Tetrahedron 1995, 51, 8863. (d) Frisell,
H.; Akermark, B. Organometallics 1995, 14, 561. (e) Trost, B. M.;
Tometzki, G. B.; Hung, M.-H. J. Am. Chem. Soc. 1987, 109, 2176. (f) Trost,
B. M.; Hung, M.-H. J. Am. Chem. Soc. 1984, 106, 6837. (g) Trost, B. M.;
Hung, M.-H. J. Am. Chem. Soc. 1983, 105, 7757.
(13) (a) Kondo, T.; Ono, H.; Satake, N.; Mitsudo, T.; Watanabe, Y.
Organometallics 1995, 14, 1945. (b) Zhang, S.; Mitsudo, T.; Kondo, T.;
Watanabe, Y. J. Organomet. Chem. 1993, 450, 197.
(14) For examples of allylic alkylation of a terminaly substituted π-allyl
palladium intermediate, see: (a) Sjogren, M. P. T.; Hansson, S.; Akermark,
B.; Vitagliano, A. Organometallics 1994, 13, 1963. (b) Trost, B. M.;
Verhoeven, T. R. J. Am. Chem. Soc. 1980, 102, 4730. (c) Fiaud, J. C.;
Malleron, J. L. Tetrahedron Lett. 1980, 21, 4437. (d) Trost, B. M.; Weber,
L.; Strege, P. E.; Fullerton, T. J.; Dietsche, T. J. J. Am. Chem. Soc. 1978,
100, 3416. (e) Trost, B. M.; Weber, L.; Strege, P. E.; Fullerton, T. J.;
Dietsche, T. J. J. Am. Chem. Soc. 1978, 100, 3426.
had a substantial effect on the selectivity and the yield of the
products. The results are summarized in Table 1. P(OPh)3 was
(5) (a) Maitlis, P. M.; Haynes, A.; Sunley, G. J.; Howard, M. J. J. Chem.
Soc., Dalton Trans. 1996, 2187. (b) Patil, R. P.; Kelkar, A. A.; Chaudhari,
R. V. J. Mol. Catal. 1992, 72, 153. (c) Behr, A.; Herdtweck, E.; Herrmann,
W. A.; Keim, W.; Kipshagen, W. Organometallics 1987, 6, 2307. (d) Kunin,
A. J.; Eisenberg, R. J. Am. Chem. Soc. 1986, 108, 535. (e) Pruett, R. L.;
Kacmarcik, R. T. Organometallics 1982, 1, 1693.
(6) For a catalytic reaction see: (a) Takaya, H.; Naota, T.; Murahashi,
S.-I. J. Am. Chem. Soc. 1998, 120, 4244. (b) Murakami, M.; Itami, K.;
Ubukata, M.; Tsuji, I.; Ito, Y. J. Org. Chem. 1998, 63, 4. (c) Chatani, N.;
Yamaguchi, S.; Fukumoto, Y.; Murai, S. Organometallics 1995, 14, 4418.
(d) Chatani, N.; Ikeda, S.; Ohe, K.; Murai, S. J. Am. Chem. Soc. 1992,
114, 9710. (e) Jun, C.-H.; Crabtree, R. H. Tetrahedron Lett. 1992, 33, 7119.
(f) Rappoli, B. J.; Churchill, M. R.; Janik, T. S.; Rees, W. M.; Atwood, J.
D. J. Am. Chem. Soc. 1987, 109, 5145. For a stoichiometric reaction see:
(g) Schwiebert, K. E.; Stryker, J. M. J. Am. Chem. Soc. 1995, 117, 8275.
(h) Wakefield, J. B.; Stryker, J. M. J. Am. Chem. Soc. 1991, 113, 7057.
(7) See ref 1e, p 25.
(8) For review see: (a) Trost, B. M.; Varanken, D. L. V. Chem. ReV.
1996, 96, 395. (b) Tsuji, J. Palladium Reagents and Catalysts; John Wiley
& Sons: New York, 1995; p 290. (c) Harrington, P. J. In ComprehensiVe
Organometallic Chemistry II; Abel, E. W., Stone, F. G. A., Wilkinson, G.,
Eds.; Pergamon: Oxford, 1995; Vol. 12, p 797. (d) Godleski, S. A. In
ComprehensiVe Organic Synthesis; Trost, B. M., Fleming, I., Eds.;
Pergamon: Oxford, 1991; Vol. 4, p 585.
(15) For a preliminary report of the work described here, see: Takeuchi,
R.; Kashio, M. Angew. Chem., Int. Ed. Engl. 1997, 36, 263.

Iridium Complex-Catalyzed Allylic Alkylations
J. Am. Chem. Soc., Vol. 120, No. 34, 1998 8649
Table 2. Effect of Catalyst Precursor on Allylic Alkylation of 1a
with 2aa
in 3 h at room temperature, while the reaction with 2c required
heating for 7 h to go to completion. Increasing the steric bulk
of carbon nucleophile reversed the regioselectivity.17 The
reaction with diethyl sodiomethylmalonate (2d) gave product
4d, resulting from alkylation at the unsubstituted allylic
terminus, in 71% selectivity (entry 4).
We examined the reaction of a series of acyclic allylic acetates
with diethyl sodiomalonate (2a) in the presence of a catalytic
amount of [Ir(COD)2Cl]2/P(OPh)3 (P/Ir ) 2) (eq 2). The results
ratio 3a/4a
entry
Ir complex
conditions
yield/%b
(E/Z)c
1d
2
3
[Ir(COD)Cl]2
room temp 3 h
89
90
84
64
0
96/4 (81/19)
95/5 (90/10)
78/22 (82/18)
60/40 (99/1)
[Ir(COD)2]BF4 THF reflux 9 h
Ir(COD)(acac) THF reflux 5 h
IrH(CO)(PPh3)3 THF reflux 28 h
4
5e
Ir4(CO)12
THF reflux 9 h
a A mixture of 1a (2 mmol), 2a (4 mmol), Ir complex (008 mmol),
P(OPh)3 (0.16 mmol), and THF (10 mL) was stirred under argon.
b Isolated yield. c Determined by GLC. d [Ir(COD)Cl]2 (0.04 mmol).
e Ir4(CO)12 (0.02 mmol).
Table 3. Allylic Alkylation of 1a with 2a
ratio 3/4
entry nucleophile
conditions
yield/%b
(E/Z)c
1
2
3
4
2a
2b
2c
2d
room temp 3 h
room temp 3 h
reflux 7 h
89
90
85
87
96/4 (81/19)
97/3 (79/21)
93/7 (80/20)
29/71 (90/10)
reflux 1 h
are summarized in Table 4. As shown in Table 4, highly
regioselective alkylation at the substituted allylic terminus was
achieved. All reactions proceeded at room temperature to give
products in an excellent yield. The reaction of cinnamyl acetate
(5b) gave 6b, resulting from alkylation at the substituted allylic
terminus, in 99% selectivity (entry 2). The regioselectivity of
5b was the same as that of 1a. The phenyl substituent on the
allylic terminus did not alter the regioselectivity as the alkyl
substituent did. With (E)-crotyl acetate (5a), (E)-2-nonenyl
acetate (5c), and (E)-2-undecenyl acetate (5d), the product from
the alkylation at the substituted allylic terminus was obtained
in 95-97% selectivity (entries 1, 3, and 4). The most unique
feature of iridium complex catalysis was demonstrated for the
reactions of 5e-g. The reactions were regiospecific at the
tertiary allylic terminus to give a product bearing a quaternary
carbon center exclusively (entries 5-9). Iridium complex-
catalyzed allylic alkylation provides an efficient method for the
construction of a quaternary carbon center,18 which is a feature
of a broad range of natural products. Several transition metal
complex-catalyzed reactions of 5g with 2a or 2b have been
reported. The iridium complex only led to exclusive formation
of a product bearing a quaternary carbon center. A Pd(PPh3)4-
catalyzed reaction19 and a NiCl2(dppe)-catalyzed reaction9j gave
7g in 38% and 10% selectivity, respectively. A Mo(CO)6-
catalyzed reaction10f gave 7gb in 85% selectivity.
a A mixture of 1a (2 mmol), 2 (4 mmol), [Ir(COD)Cl]2 (0.04 mmol),
P(OPh)3 (0.16 mmol), and THF (10 mL) was stirred under argon.
b Isolated yield. c Determined by GLC.
room temperature (entry 2). The reaction using 3 equiv of
P(OPh)3 to each equivalent of Ir did not go to completion (entry
4). The yield of products and the selectivity of 3a were
decreased. The use of P(O4-MeC6H4)3, P(O4-FC6H4)3, P(O-
2-naph)3, and PPh(OPh)2 as ligands gave an excellent selectivity
of 3a, but the reactions required a longer reaction time compared
to that needed when using P(OPh)3 (entries 7-10). With
P(OEt)3 or P(Oi-Pr)3, the reaction gave 3a in a much decreased
selectivity (entries 11 and 12). Reactions in which a more
electron-donating phosphorus ligand such as PPh3, P(n-Bu)3,
or dppe was used gave products in poor yields (entries 13-
15). Carbonate 1b and phosphate 1c could be used as substrates
successfully. The reaction of carbonate 1b gave 3a in 97%
selectivity (entry 5), but the reaction of phosphate 1c decreased
the selectivity of 3a slightly (entry 6). It is well-known that
the palladium complex-catalyzed reaction of allylic carbonates
with dialkyl malonate proceeds under neutral conditions.16 The
reaction of 1b with diethyl malonate under refluxing THF in
the presence of [Ir(COD)Cl]2/P(OPh)3 for 24 h gave no
corresponding products. The starting materials were recovered.
The catalytic activity of several iridium complexes combined
with P(OPh)3 (P(OPh)3/Ir ) 2) was examined in the reaction
of 1a with diethyl sodiomalonate (2a) (Table 2). [Ir(COD)-
Cl]2 gave the best result (entry 1). The reaction using a cationic
iridium complex required heating, but the yield of products and
the selectivity of 3a were the same as in the reaction using [Ir-
(COD)Cl]2 (entry 2). Use of Ir(COD)(acac) decreased the
selectivity of 3a (entry 3). IrH(CO)(PPh3)3 alone was totally
ineffective as a catalyst. IrH(CO)(PPh3)3/P(OPh)3 showed some
catalytic activity (entry 4). Ir4(CO)12/P(OPh)3 was totally
ineffective as a catalyst (entry 5).
Regioisomeric acetates of 1a, 5b, and 5d were used as
substrates (eq 3). Reactions with 2a gave the same product
Reaction of 1a with various stabilized carbon nucleophiles
was examined. The results are summarized in Table 3. The
reaction of 1a with 2a-c gave products 3a-c, resulting from
alkylation at the substituted allylic terminus, in 93-97%
selectivity (entries 1-3). Nucleophiles 2a and 2b were more
reactive than 2c. Reaction of 1a with 2a and 2b was completed
(16) (a) Tsuji, J.; Minami, I. Acc. Chem. Res. 1987, 20, 140. (b) Tsuji,
J. Tetrahedron 1986, 42, 4361. (c) Tsuji, J.; Shimizu, I.; Minami, I.; Ohashi,
Y.; Sugiura, T.; Takahashi, K. J. Org. Chem. 1985, 50, 1523. (d) Tsuji, J.;
Shimizu, I.; Minami, I.; Ohashi, Y. Tetrahedron Lett. 1982, 23, 4809.
distributions as those given by 1a, 5b, and 5d. The selectivity

8650 J. Am. Chem. Soc., Vol. 120, No. 34, 1998
Table 4. Allylic Alkylation of 5a
Takeuchi and Kashio
entry
substrate
nucleophile
product
conditions
yield/%b
ratio 6/7c
1
2
3
4
5a R1 ) Me, R2 ) R3 ) H
2a
2a
2a
2a
2a
2a
2a
2b
2b
6a, 7a
6b, 7b
6c, 7c
6d, 7d
6e, 7e
room temp 2 h
room temp 3 h
room temp 5 h
room temp 5 h
room temp 2 h
room temp 16 h
room temp 16 h
room temp 2 h
room temp 16 h
77
98
99
95
80
80
85
70
80
97/3d
99/1e
95/5f
5b R1 ) Ph, R2 ) R3 ) H
5c R1 ) n-Hex, R2 ) R3 ) H
5d R1 ) n-Oct, R2 ) R3 ) H
5e R1 ) H, R2 ) R3 ) Me
95/5g
0/100
0/100
0/100
0/100
0/100
5h
6h
7h
8
5f R1 ) H, R2 ) Me, R3 ) n-Bu
5g R1 ) H, R2 ) Me, R3 ) CH2CH2C ) CMe2
5e R1 ) H, R2 ) R3 ) Me
6f, 7f
6g, 7g
6eb, 7eb
6gb, 7gb
9h,i
5g R1 ) H, R2 ) Me, R3 ) CH2CH2C ) CMe2
a A mixture of 5 (2 mmol), 2 (4 mmol), [Ir(COD)Cl]2 (0.04 mmol), P(OPh)3 (0.16 mmol), and THF (10 mL) was stirred under argon. b Isolated
yield. c Determined by GLC. d Ratio fo E/Z was not determined. e E/Z ) 100/0. f E/Z ) 66/34. g E/Z ) 69/31. h 2 (6 mmol). i [Ir(COD)Cl]2 (0.08
mmol), P(OPh)3 (0.32 mmol).
Table 5. Allylic Alkylation of Allylic Alcohol 10 with 2aa
of the alkylation at the substituted allylic terminus was 95-
99%. The result strongly suggests the intermediacy of a π-allyl
iridium complex.
3-Methyl-2-butenyl acetate (9a) failed to react with 2a under
refluxing dioxane for 24 h. The corresponding product was
not obtained at all. 3-Substituted 2-alkenyl acetate was much
less reactive than 2-alkenyl acetate. Changing the leaving group
enhanced the reactivity of the substrate (eq 4). The reactions
entry
substrate
yield/%b
product
ratioc
1
2
3
4
5
6
10a R1 ) n-Pr, R2 ) H
10b R1 ) Me, R2 ) H
10c R1 ) Ph, R2 ) H
10d R1 ) n-Hex, R2 ) H
10e R1 ) n-Oct, R2 ) H
10f R1 ) H, R2 ) Me
100
74
98
84
80
71
3a/4a
6a/7a
6b/7b
6c/7c
6d/7d
11
96/4d
96/4e
99/1f
95/5g
93/7n
a A mixture of 10 (2 mmol), 2a (6 mmol), [Ir(COD)Cl]2 (0.04 mmol),
P(OPh)3 (0.16 mmol), and THF (10 mL) was stirred under reflux for
1 h. b Isolated yield. c Determined by GLC. d E/Z ) 68/32. e Ratio of
E/Z was not determined. f E/Z ) 100/0. g E/Z ) 63/37. h E/Z ) 71/
29.
gioselective and required extreme reaction conditions. Several
allylic alcohols were smoothly alkylated at the substituted allylic
terminus in high selectivities under mild conditions (eq 5).
Results are summarized in Table 5. The reaction (E)-2-hexen-
1-ol (10a) with 2a under refluxing THF for 1 h gave products
in a quantitative yield (entry 1). The selectivity of 3a was 96%.
(E)-Crotyl alcohol (10b), (E)-cinnamyl alcohol (10c), (E)-2-
nonen-1-ol (10d), and (E)-2-undecen-1-ol (10e) reacted with
2a similarly to give products from alkylation at the substituted
allylic terminus in high selectivities (entries 2-5). 1-Alken-
3-ol was less reactive than 2-alken-1-ol. The reaction of
1-hexen-3-ol with 2a was sluggish (eq 6). The yield of products
of diethyl 3-methyl-2-butenyl phosphate (9d) and 3-methyl-2-
butenyl trifluoroacetate (9c) with 2a proceeded at room tem-
perature. Product 7e from the alkylation at the disubstituted
allylic terminus was obtained in 96% and 95% selectivity,
respectively. The reactivity of leaving groups was in the order
of (EtO)2PO2 ∼ CF3CO2 > MeO2CO > AcO. The low
reactivity of 3-methyl-2-butenyl acetate compared to that of
2-alkenyl acetate is attributed to the difficulty in the coordination
of the carbon-carbon double bond to an iridium complex prior
to the oxidative addition. It is well-known that the coordination
of an alkene to the transition metal complexes is quite sensitive
to steric effects.20
Allylic Alkylation of Allylic Alcohols. Allylic esters were
successfully used as substrates. If allylic alcohols can be used
as substrates, the reaction might be far more beneficial.
Bergbreiter reported that Pd(PPh3)4 catalyzed the reaction of
allylic alcohols with R-ketoesters.21 The reaction was nonre-
(17) Use of a steric demanding nucleophile increased the selectivity of
alkylation at the unsubstituted allylic terminus; see ref 14e.
(18) Martine, S. F. Tetrahedron 1980, 36, 419.
(19) Cuvigny, T.; Julia, M.; Roland, C. J. Organomet. Chem. 1985, 285,
395.
(20) (a) Tolman, C. A. J. Am. Chem. Soc. 1974, 96, 2780. (b) Cramer,
R. J. Am. Chem. Soc. 1967, 89, 4621.
and the selectivity of 3a were decreased. The reaction of
(21) Bergbreiter, D. E.; Weatherford, D. A. J. Chem. Soc., Chem.
Commun. 1989, 883.

Iridium Complex-Catalyzed Allylic Alkylations
J. Am. Chem. Soc., Vol. 120, No. 34, 1998 8651
Table 6. Allylic Alkylation of (Z)-Allylic Esters (13) with 2aa
entry
substrate
ligand
conditions
yield/%b
product
ratioc
1d
2
3
4
5
6
7
13a R1 ) n-Pr, X ) Ac
P(OPh)3
room temp 2 h
reflux 5 h
room temp 5 h
reflux 22 h
reflux 3 h
reflux 3 h
reflux 4 h
81
85
81
72
86
84
85
3a/(E)-4a/(Z)-4a
3a/(E)-4a/(Z)-4a
3a/(E)-4a/(Z)-4a
6b/(E)-7b/(Z)-7b
6c/(E)-7c/(Z)-7c
6d/(E)-7d/(Z)-7d
14f/(E)-15f/(Z)-15f
25/5/70
3/7/90
8/5/87
55/5/40
2/9/89
2/11/87
4/21/75
13a R1 ) n-Pr, X ) Ac
P(O2-t-Bu4-MeC6H3)3
P(O2-t-Bu4-MeC6H3)3
P(O2-t-Bu4-MeC6H3)3
P(O2-t-Bu4-MeC6H3)3
P(O2-t-Bu4-MeC6H3)3
P(O2-t-Bu4-MeC6H3)3
13b R1 ) n-Pr, X ) PO(OEt)2
13c R1 ) Ph, X ) Ac
13d R1 ) n-Hex, X ) Ac
13e R1 ) n-Oct, X ) Ac
13f R1 ) PhCH2CH2CH2, X ) Ac
a A mixture of 13 (2 mmol), 2a (4 mmol), [Ir(COD)Cl]2 (0.04 mmol), P(O2-t-Bu4-MeC6H3)3 (0.08 mmol), and THF (10 mL) was stirred under
argon. b Isolated yield. c Determined by GLC. d P(OPh)3 (0.16 mmol).
3-methyl-2-buten-1-ol and linalol with 2a did not give the
corresponding products.
plexes undergo syn-anti isomerization.22 If such isomerization
occurs prior to the alkylation, the reactions of (E)-2-alkenyl ester
and (Z)-2-alkenyl ester should give the same product distribu-
tion. This result showed that the alkylation occurred prior to
syn-anti isomerization and the regioselectivity of the alkylation
to syn π-allyl iridium complex was different from that of
alkylation to the anti π-allyl iridium complex.
Allylic alcohols were found to be good substrates for our
allylic alkylation. The low reactivity of allylic alcohol toward
oxidative addition is well known. Transesterification of allylic
alcohol to the more reactive ester 12 prior to oxidative addition
might be possible. The resulting ester 12 would oxidatively
add to an iridium center to give a π-allyl iridium intermediate.
We examined the possibility of formation of ester 12 during
the reaction. The reaction of 12a (R ) n-Pr) with 2a under
refluxing THF for 1 h gave products in 99% yield. The
selectivity of 3a was 95%. Ester 12a (R ) n-Pr) gave the same
results as alcohol 10a. We carried out the reaction of 10a with
1 equiv of 2a. If transesterification occured, the yields of 3a
and 4a should have decreased below 50%. The reaction gave
products in 40% yield. Furthermore, a considerable formation
of ester 12a (R ) n-Pr) was observed in the reaction of 10a
with 2a under refluxing THF in the absence of catalyst.
According to these results, we concluded that an initial
intermediate was ester 12 formed by the transesterification.
However, allylic alcohols could be practically used as a substrate
for the reaction.
Palladium complex-catalyzed allylic alkylation of (Z)-2-
alkenyl acetate resulted in a loss of the geometry of the starting
material14a,b because the anti π-allyl palladium complex easily
isomerized to the thermodynamically more stable syn π-allyl
palladium complex.23 As mentioned above, the ratio of (Z)-
4a/(E)-4a was 93/7. Syn-anti isomerization of a terminally
monosubstituted π-allyl iridium complex is quite slow compared
to that of a terminally monosubstituted π-allyl palladium
complex. Iridium catalysis provides a possibility of (Z)-selective
allylic alkylation.10b,12d,24 However, in the reaction of (Z)-2-
alkenyl acetate, the regioselectivity of alkylation leading to (Z)-
alkene is not satisfactory. To improve the selectivity of (E)-
and (Z)-alkene, alkylation must be directed to the unsubstituted
allylic terminus. A bulky phosphite ligand is expected to
increase such selectivity. We examined the reaction of (Z)-2-
alkenyl ester with 2a using a bulky phosphite ligand. The results
are summarized in Table 6. The reaction using 1 equiv of tris-
(2-tert-butyl-4-methylphenyl)phosphite to each equivalent of
iridium under refluxing THF for 3 h gave the product in 85%
yield (entry 2). The selectivity of (Z)-4a was increased to 90%.
The ratio of phosphite to iridium was critical. The same reaction
using 2 equiv of tris(2-tert-butyl-4-methylphenyl)phosphite to
each equivalent of iridium under refluxing THF for 24 h gave
no product. The starting material was recovered. Phosphate
was more reactive than acetate. The reaction of diethyl (Z)-2-
hexenyl phosphate (13b) was completed in 3 h at room
temperature, but the selectivity of (Z)-4a was not improved
(entry 3). The phenyl substituent showed a preference for
alkylation at the substituted allylic terminus to decrease (Z)-
selectivity. The reaction of (Z)-cinnamyl acetate (13c) using
tris(2-tert-butyl-4-methylphenyl)phosphite gave (Z)-7b in 40%
selectivity (entry 4). Compound 6b resulting from the alkylation
at the substituted allylic terminus was obtained in 55% selectiv-
ity. The reactions of (Z)-2-nonenyl acetate (13d) and (Z)-2-
undecenyl acetate (13e) with 2a gave (Z)-7c and (Z)-7d in 89%
and 87% selectivity, respectively (entries 5 and 6). The reaction
Allylic Alkylation of (Z)-Allylic Esters. The stereochemistry
of the carbon-carbon double bond in the allyl system affected
the regiochemistry of the allylic alkylation. The reaction of
(Z)-2-hexenyl acetate (13a) with 2a at room temperature gave
products in 81% yield (eq 7). The major product was (Z)-4a
(22) (a) Crabtree, R. H. The Organometallic Chemistry of the Transition
Metals; John Wiley & Sons: New York, 1994; p 112. (b) Collman, J. P.;
Hegedus, L. S.; Norton, J. R.; Finke, R. G. Principles and Applications of
Organotransition Metal Chemistry; University Science Book: Mill Valley,
1987; p 175.
(23) (a) Sjogren, M.; Hansson, S.; Norrby, P.; Akermark, B.; Cucciolito,
M. E.; Vitagliano, A. Organometallics 1992, 11, 3954. (b) Akermark, B.;
Hansson, S.; Vitagliano, A. J. Am. Chem. Soc. 1990, 112, 4587.
(24) Akermark reported that 2,9-disubstituted-1,10-phenanthroline could
stabilize anti π-allyl palladium complex and its use for Pd-catalyzed allylic
alkylation. The reaction of (Z)-2-hexenyl acetate with diethyl sodiometh-
ylmalonate gave (Z)-product in 72% selectivity; see ref 14a.
resulting from alkylation at the unsubstituted allylic terminus.
The selectivity of 4a was 75% (E/Z ) 7/93) (Table 6 entry 1).
The regioselectivity was opposite that for the reaction of (E)-
2-hexenyl acetate (1a) with 2a.
Oxidative addition of (E)-2-alkenyl acetate gives a syn π-allyl
iridium complex as an intermediate, while oxidative addition
of (Z)-2-alkenyl acetate gives an anti π-allyl iridium complex
as an intermediate. It is well-known that π-allyl metal com-

8652 J. Am. Chem. Soc., Vol. 120, No. 34, 1998
Takeuchi and Kashio
of 13f, where a phenyl group is substituted away from the allylic
terminus, gave (Z)-15f in 75% selectivity (entry 7).
(P/Ir ) 3) showed three doublets of doublets (δ 71.7, 86.1, and
95.9 J ) 30, 24 Hz). The singlet and two sets of doublets shown
in the reaction at P/Ir ) 2 disappeared. As mentioned above,
the allylic alkylation was highly regioselective at the ratios of
P/Ir ) 1 and 2 (Table 1 entries 2-4). It is clear that the
monophosphite species is catalytically active. The presence of
one molecule of P(OPh)3 on the π-allyl iridium intermediate is
necessary for the high regioselectivity. Since P(OPh)3 is a better
π-acceptor,27 it promotes a carbonium ion character at the
substituted allylic terminus and directs the nucleophilic attack
to this position.28,29 In agreement with this, when a ligand with
weaker acceptor properties was used such as P(OEt)3 or P(Oi-
Pr)3, the reaction was much less selective (Table 1 entries 11
and 12).
The regioselectivity of the reaction of (Z)-2-alkenyl acetate
is different from that of (E)-2-alkenyl acetate. The difference
is explained as follows. Nucleophilic attack at the substituted
allylic terminus in the anti π-allyl iridium intermediate would
bring the anti substituent close to the iridium moiety. The steric
interaction gives an unfavorable transition state.30 On the other
hand, such steric interaction does not occur in the alkylation at
the substituted allylic terminus of the syn π-allyl iridium
intermediate. Thus, alkylation at the unsubstituted allylic
terminus is favored in the case of (Z)-2-alkenyl acetate.
The reaction of (Z)-2-alkenyl esters gave a small amount of
(E)-product. We examined the formation of the (E)-product
under the reaction conditions. Treatment of a 23:4:73 mixture
of 3a, (E)-4a, and (Z)-4a with 2 equiv of 2a in the presence of
a catalytic amount of [Ir(COD)Cl]2 and P(OPh)3 (P/Ir ) 2) for
4 h at room temperature gave a 23:17:60 mixture of 3a, (Z)-4a,
and (Z)-4a. The ratio of (Z)-4a decreased, while the ratio of
(E)-4a increased. Isomerization of (Z)-4a to (E)-4a occurred.
According to the result, we concluded that a small amount of
(E)-product was formed by the isomerization of an initially
formed (Z)-product during the alkylation.
Stereochemical Course of Allylic Alkylation. The stereo-
chemical course of the reaction was examined. We chose (Z)-
5-(methoxycarbonyl)-2-cyclohexen-1-yl methyl carbonate (16)
as a substrate because it was extensively used to examine the
stereochemical course of palladium14b and molybdenum complex-
catalyzed10f,j allylic alkylation. Unlike the reactions with the
acyclic systems mentioned above, this reaction was quite
sluggish and did not go to completion (eq 8). Product 17 was
Conclusion
An iridium complex was found to be a new and efficient
catalyst for allylic alkylation. The structure of the allyl system
greatly affected the reaction. With (E)-2-alkenyl esters and
1-substituted-2-propenyl esters, highly regioselective alkylation
at the substituted allylic terminus was achieved. With (Z)-2-
alkenyl esters, the regioselectivity was opposite that of the (E)-
2-alkenyl esters. (Z)-Selective allylic alkylation at the unsub-
stituted allylic terminus could be achieved. The selectivity
described here complements palladium catalysis. These unique
features will make iridium complexes a useful tool for the
carbon-carbon bond forming reaction.
obtained in 37% yield. The starting material was recovered in
40% yield. The product of net retention of configuration was
obtained exclusively. This suggests the reaction proceeds with
a double inversion mechanism.25
Discussion
Regioselectivity of allylic alkylation is controlled by three
factors: (1) the steric interaction between the incoming nucleo-
phile and the allylic terminus, (2) the charge distribution of the
π-allyl ligand on the metal, and (3) the stability of the resulting
alkene-metal complexes as an initial product. When the
nucleophile is 2a, results described here indicate factor 1 is not
important. With regard to factor 3, it is clear that alkylation at
the substituted allylic terminus results in the formation of the
more stable terminal alkene complex as an initial product.26
P(OPh)3 plays a crucial role with regard to factor 2. We
examined the reaction of [Ir(COD)Cl]2 with P(OPh)3 in d8-THF
by 31P NMR. The 31P NMR spectra of a mixture of [Ir(COD)-
Cl]2 and P(OPh)3 (P/Ir ) 1) showed a singlet (δ 86.9). No
free P(OPh)3 was detected. This indicated the formation of a
monophosphite species. Increasing the amount of P(OPh)3 led
to the appearance of a new set of signals. The 31P NMR spectra
of a mixture of [Ir(COD)Cl]2 and P(OPh)3 (P/Ir ) 2) showed a
singlet (δ 86.9), three sets of doublets of doublets (δ 71.7, 86.1,
and 95.9, J ) 30, 24 Hz), and two sets of doublets (δ 96.3 and
101.8, J ) 24 Hz) in a ratio of 42:42:16. The reaction of [Ir-
(COD)Cl]2 with 2 equiv of P(OPh)3 formed three species. The
31P NMR spectra of a mixture of [Ir(COD)Cl]2 and P(OPh)3
Experimental Section
Materials. All reagents and solvents were dried and purified before
use by the usual procedures. Allylic esters were prepared by the
(27) P(OPh)3 is more electron withdrawing than PPh3; see Tolman, C.
A. Chem. ReV. 1997, 77, 313.
(28) (a) Akermark, B.; Hansson, S.; Krankenberger, B.; Vitagliano, A.;
Zetterberg, K. Organometallics 1984, 3, 679. (b) Akermark, B.; Zetterberg,
K.; Hansson, S.; Krankenberger, B.; Vitagliano, A. J. Organomet. Chem.
1987, 335, 133. (c) Pretot, R.; Pfaltz, A. Angew. Chem., Int. Ed. Engl. 1998,
37, 323.
(29) The reaction of 1b with diethyl malonate resulted in the recovery
of the starting material, while the reaction of 1b with diethyl sodiomalonate
gave products in 94% yield (Table 1, entry 5). It is well-known that the
formation of MeO- by the dissociation from the metal center is necessary
for the reaction of allylic carbonates under neutral conditions.16 The result
indicates that dissociation of MeO- from the iridium center did not occur.
The leaving group from the allylic ester coordinates on iridium. According
to the result, an intermediate is presumed to be [Ir(π-allyl)Cl(OAc)-
(P(OPh)3)]. To avoid a steric repulsion of the substituted allylic terminus,
triphenyl phosphite coordinates trans to the substituted allylic terminus.
(30) (a) Birch, A. J.; Pearson, A. J. J. Chem. Soc., Perkin Trans. 1 1976,
954. (b) Similar dependency of the regioselectivity on the stereochemistry
of the allyl system was observed. The Fe2(CO)9-catalyzed reaction of (E)-
crotyl acetate with dimethyl sodiomalonate gave the product from the
alkylation at the substituted allylic terminus as a major product, whereas
the same reaction of (Z)-crotyl acetate gave the product from the alkylation
at the unsubstituted allylic terminus as a major product; see ref 11d.
(25) For a mechanism with double inversion of configuration, see: (a)
Hayashi, T.; Yamamoto, A.; Hagihara, T. J. Org. Chem. 1986, 51, 723. (b)
Fiaud, J. C.; Legros, J. Y. J. Org. Chem. 1987, 52, 1907. A mechanism
with double retention of configuration cannot be ruled out; see ref 10h.
(26) A complex of terminal alkenes is more stable than that of internal
alkenes: see ref 20b.

Iridium Complex-Catalyzed Allylic Alkylations
J. Am. Chem. Soc., Vol. 120, No. 34, 1998 8653
reaction of the corresponding alcohols with acetyl chloride, methyl
chloroformate, diethyl chlorophosphate, or trifluoroacetic anhydride.
Acetates 1a, 5b, and 5g were purchased. Alcohols 10a-f, 2-methyl-
3-buten-2-ol, 1-hexen-3-ol, and (Z)-2-hexen-1-ol were purchased.
1-Phenyl-2-propen-1-ol was prepared by the reaction of benzaldehyde
with vinylmagnesium bromide. 2-Alkyn-1-ols were prepared by the
reaction of 1-alkynyllithium with paraformaldehyde.31 (Z)-3-Phenyl-
2-propen-1-ol, (Z)-2-nonen-1-ol, (Z)-2-undecen-1-ol, and (Z)-6-phenyl-
2-hexen-1-ol were prepared by the hydrogenation of the corresponding
2-alkyn-1-ols. Ester 12a was prepared by the transesterification of
diethyl malonate with sodium (E)-2-hexenyloxide. Methyl (Z)-5-
hydroxy-3-cyclohexenecarboxylate was prepared according to the
published method.14b [Ir(COD)Cl]2,32 [Ir(COD)2]BF4,33 and IrH(CO)-
(PPh3)334 were prepared according to the published methods. Ir(COD)-
(acac) and Ir4(CO)14 were purchased. P(O-4-MeC6H4)3,35 P(O-4-
FC6H4)3,35 P(O-2-Naph)3,35 P(O-2-tert-Bu-4-MeC6H4)3,35 and PPh(OPh)236
were prepared according to the published methods. Lindlar catalyst
was purchased from Wako.
General Methods. 1H NMR and 13C NMR spectra were measured
on a JEOL-EX-270 spectrometer using Me4Si as an internal standard.
Samples were dissolved in CDCl3 solutions. 31P NMR spectra were
measured on a JEOL JNM GX-400 spectrometer using H3PO4 as an
external standard. GC analyses were performed on a Shimadzu GC-
14A using 3 mm × 2 m glass columns packed with either 5% PEG-
HT on 60/80 mesh Chromosorb w, AW-DMCS or 5% OV-17 on 60/
80 mesh chromosorb w, AW-DMCS, and a Shimadzu GC-17A using
60 m × 0.25 mm SP-2331 and 30 m × 0.25 mm DB-17 columns.
Column chromatography was carried out on 70/230 mesh silica gel
(Merk; Silica Gel 60). Elemental analyses were performed at the
Microanalytical Center of Kyoto University. Samples for elemental
analysis were purified by preparative gas chromatography.
under Ar atmosphere. In a separate flask, diethyl malonate (640 mg,
4.0 mmol) was added to a slurry of hexane-washed sodium hydride
(96 mg, 4.0 mmol) in 5.0 mL of THF. The resulting clear solution
was added to the former by a syringe, and the combined mixture was
stirred at room temperature for 3 h. The progress of the reaction was
monitored by GLC. After 1a was consumed, the reaction mixture was
partitioned between ether and water. The organic layer was separated,
and the aqueous layer was extracted with ether. The combined organic
layer was concentrated in vacuo. The residue was purified by column
chromatography (n-hexane/ethyl acetate (98/2)) to give 3a and 4a as a
mixture (431 mg, yield 89%).
Allylic Alkylation of Allylic Alcohols. A typical procedure is
described for the reaction of 10a with 2a. (E)-2-Hexen-1-ol 10a (200
mg, 2.0 mmol), triphenyl phosphite (49.6 mg, 0.16 mmol), and [Ir-
(COD)Cl]2 (26.9 mg, 0.04 mmol) were stirred in 5.0 mL of THF under
Ar atmosphere. In a separate flask, diethyl malonate (640 mg, 4.0
mmol) was added to a slurry of hexane-washed sodium hydride (96
mg, 4.0 mmol) in 5.0 mL of THF. The resulting clear solution was
added to the former by a syringe, and the combined mixture was stirred
under refluxing THF for 1 h. The progress of the reaction was
monitored by GLC. After 10a was consumed, the reaction mixture
was partitioned between ether and water. The organic layer was
separated, and the aqueous layer was extracted with ether. The
combined organic layer was concentrated in vacuo. The residue was
purified by column chromatography (n-hexane/ethyl acetate (98/2)) to
give 3a and 4a as a mixture (480 mg, yield 99%).
Ethyl 3-Ethenyl-2-ethoxycarbonylhexanoate (3a): 1H NMR δ 0.88
(t, J ) 6.9 Hz, 3H), 1.25 (t, J ) 7.3 Hz, 3H), 1.27 (t, J ) 7.3 Hz, 3H),
1.33-1.45 (m, 4H), 2.78 (qd, J ) 8.9, 3.3 Hz, 1H), 3.33 (d, J ) 8.9
Hz, 1H), 4.15 (q, J ) 7.3 Hz, 2H), 4.20 (q, J ) 7.3 Hz, 2H), 5.06 (dd,
J ) 10.2, 2.0 Hz, 1H), 5.07 (dd, J ) 17.5, 2.0 Hz, 1H), 5.65 (dt, J )
17.5, 9.9 Hz, 1H); 13C NMR δ 13.7, 14.0 (2C), 20.0, 34.3, 43.8, 56.9,
61.0, 61.1, 117.1, 138.1, 168,1, 168.3. Anal. Calcd for C13H22O4: C,
64.44; H, 9.15; O, 26.41. Found: C, 64.37; H, 9.16.
Ethyl (E)-2-Ethoxycarbonyl-4-octenoate ((E)-4a):37 1H NMR δ
0.86 (t, J ) 7.3 Hz, 3H), 1.26 (t, J ) 7.3 Hz, 6H), 1.35 (sextet, J )
7.6 Hz, 2H), 1.95 (q, J ) 6.9 Hz, 2H), 2.58 (t, J ) 6.9 Hz, 2H), 3.37
(t, J ) 6.9 Hz, 1H), 4.19 (q, J ) 7.3 Hz, 4H), 5.36 (dt, J ) 15.5, 6.9
Hz, 1H), 5.52 (dt, J ) 15.5, 6.9 Hz, 1H); 13C NMR δ 13.4, 14.0 (2C),
22.3, 31.8, 34.4, 52.3, 61.2 (2C), 125.4, 133.6, 169.0 (2C).
Preparation of (Z)-2-Alken-1-ol. A typical procedure is described
for preparation of (Z)-3-phenyl-2-propen-1-ol. A mixture of 3-phenyl-
2-propyn-1-ol (3.272 g, 24.4 mmol), Lindlar catalyst (1.316 g), and
3,6-dithia-1,8-octanediol (4.1 mg) was vigorously stirred in toluene (20
mL) at room temperature under a hydrogen atmosphere for 24 h. The
progress of the reaction was monitored by GLC. After the 3-phenyl-
2-propyn-1-ol was consumed, the reaction mixture was filtered. After
toluene was removed in vacuo, distillation of the residue gave (Z)-3-
phenyl-2-propen-1-ol (3.274 g, yield 95%).
(Z)-3-Phenyl-2-propen-1-ol: 1H NMR δ 2.82 (br, 1H), 4.37 (dd, J
) 6.6, 2.0 Hz, 2H), 5.81 (dt, J ) 11.9, 6.3 Hz, 1H), 6.49 (d, J ) 11.9
Hz, 1H), 7.14-7.33 (m, 5H); 13C NMR δ 59.3, 127.0, 128.1 (2C),
128.6 (2C), 130.5, 131.2, 136.4.
Ethyl (Z)-2-Ethoxycarbonyl-4-octenoate ((Z)-4a): 1H NMR δ 0.90
(t, J ) 7.3 Hz, 3H), 1.27 (t, J ) 7.3 Hz, 6H), 1.37 (sextet, J ) 7.3 Hz,
2H), 2.04 (q, J ) 7.3 Hz, 2H), 2.64 (t, J ) 7.3 Hz, 2H), 3.35 (t, J )
7.3 Hz, 1H), 4.19 (q, J ) 7.3 Hz, 4H), 5.32 (dt, J ) 10.9, 7.3 Hz, 1H),
5.48 (dt, J ) 10.9, 7.3 Hz, 1H); 13C NMR δ 13.6, 14.0 (2C), 22.5,
26.6, 29.1, 52.0, 61.2 (2C), 124.7, 132.8, 169.0 (2C). Anal. Calcd
for C13H22O4: C, 64.44; H, 9.15; O, 26.41. Found: C, 64.64; H, 9.34.
Methyl 3-Ethenyl-2-methoxycarbonylhexanoate (3b):14c 1H NMR
δ 0.89 (t, 3H, J ) 7.3 Hz), 1.19-1.45 (m, 4H), 2.78 (qd, J ) 8.9, 3.3
Hz, 1H), 3.39 (d, J ) 8.9 Hz, 1H), 3.69 (s, 3H), 3.73 (s, 3H), 5.07 (dd,
J ) 9.4, 1.7 Hz, 1H), 5.08 (ddd, J ) 17.8, 2.0, 0.7 Hz, 1H), 5.63 (dt,
J ) 17.8, 9.7 Hz, 1H); 13C NMR δ 13.6, 20.0, 34.3, 43.9, 52.0, 56.8
(2C), 117.2, 138.0, 168.4, 168.6.
Methyl (E)-2-Methoxycarbonyl-4-octenoate ((E)-4b):38 1H NMR
δ 0.86 (t, J ) 7.3 Hz, 3H), 1.35 (sextet, J ) 7.3 Hz, 2H), 1.95 (q, J )
6.9 Hz, 2H), 2.58 (td, J ) 6.9, 1.0 Hz, 2H), 3.42 (t, J ) 7.6 Hz, 1H),
3.72 (s, 6H), 5.35 (dt, J ) 15.2, 6.6 Hz, 1H), 5.52 (dt, J ) 15.2, 6.6
Hz, 1H); 13C NMR δ 13.3, 22.3, 31.8, 34.4, 51.9, 52.2 (2C), 125.2,
133.8, 169.3 (2C).
(Z)-2-Nonen-1-ol: 1H NMR δ 0.88 (t, J ) 6.6 Hz, 3H), 1.22-1.40
(m, 8H), 2.06 (q, J ) 6.6 Hz, 2H), 2.32 (br, 1H), 4.17 (d, J ) 5.6 Hz,
2H), 5.51 (dt, J ) 11.2, 6.9 Hz, 1H), 5.58 (dt, J ) 11.2, 6.3 Hz, 1H);
13C NMR δ 14.0, 22.5, 27.3, 28.8, 29.5, 31.6, 58.3, 128.4, 132.8.
(Z)-2-Undecen-1-ol: 1H NMR δ 0.88 (t, J ) 6.6 Hz, 3H), 1.20-
1.35 (m, 12H), 1.82 (br, 1H), 2.06 (q, J ) 6.3 Hz, 2H), 4.18 (d, J )
5.9 Hz, 2H), 5.52 (dt, J ) 11.2, 6.9 Hz, 1H), 5.59 (dt, J ) 11.2, 5.9
Hz, 1H); 13C NMR δ 14.0, 22.6, 27.4, 29.18, 29.22, 29.4, 29.6, 31.8,
58.4, 128.3, 133.0.
1
(Z)-6-Phenyl-2-hexen-1-ol: H NMR δ 1.69 (quintet, J ) 7.3 Hz,
2H), 1.94 (br, 1H), 2.09 (q, J ) 7.3 Hz, 2H), 2.60 (t, J ) 7.3 Hz, 2H),
4.12 (d, J ) 5.9 Hz, 2H), 5.52 (dt, J ) 11.2, 6.9 Hz, 1H), 5.60 (dt, J
) 11.2, 6.3 Hz, 1H), 7.14-7.33 (m, 5H); 13C NMR δ 26.8, 31.1, 35.2,
58.3, 125.7, 128.2 (2C), 128.3 (2C), 128.9, 132.2, 142.0.
Allylic Alkylation of Allylic Esters. A typical procedure is
described for the reaction of 1a with 2a. (E)-2-Hexenyl acetate 1a
(284 mg, 2.0 mmol), triphenyl phosphite (49.6 mg, 0.16 mmol), and
[Ir(COD)Cl]2 (26.9 mg, 0.04 mmol) were stirred in 5.0 mL of THF
Methyl (Z)-2-Methoxycarbonyl-4-octenoate ((Z)-4b): 1H NMR
δ 0.90 (t, J ) 7.3 Hz, 3H), 1.37 (sextet, J ) 7.3 Hz, 2H), 2.04 (q, J )
7.3 Hz, 2H), 2.65 (t, J ) 7.6 Hz, 2H), 3.40 (t, J ) 7.6 Hz, 1H), 3.73
(s, 6H), 5.30 (dt, J ) 10.9, 7.3 Hz, 1H), 5.49 (dt, J ) 10.9, 7.3 Hz,
1H); 13C NMR δ 13.6, 22.5, 26.7, 29.1, 51.7, 52.3 (2C), 124.4, 133.0,
169.3 (2C). Anal. Calcd for C11H18O4: C, 61.66; H, 8.47; O, 29.87.
Found: C, 61.77; H, 8.68.
(31) Denis, J.-N.; Greene, A. E.; Serra, A. A.; Luche, M.-J. J. Org. Chem.
1986, 51, 46.
(32) Crabtree, R. H.; Quirk, J. M.; Felkin, H.; Fillebeen-Khan, T. Synth.
React. Inorg. Met.-Org. Chem. 1982, 12, 407.
(33) Schenck, T. G.; Downs, J. M.; Milne, C. R. C.; Mackenzie, P.;
Boucher, H.; Whealan, J.; Bosnich, B. Inorg. Chem. 1985, 24, 2334.
(34) Wilkinson, G. Inorg. Synth. 1972, 13, 126.
Ethyl 3-Ethenyl-2-(1-oxoethyl)hexanoate (3c):13b A mixture of 1:1
diastereomer 1H NMR δ 0.86-0.90 (m, 3H × 2), 1.25 (t, J ) 7.3 Hz,
(35) Van Rooy, A.; Orij, E. N.; Kamer, P. C. J.; Van Leeuwen, P. W.
N. M. Organometallics 1995, 14, 34.
(36) Hoffmann, F. W.; Moore, T. R. J. Am. Chem. Soc. 1958, 80, 1150.
(37) Hiyama, T.; Morizawa, Y.; Yamamoto, H.; Nozaki, H. Bull. Chem.
Soc. Jpn. 1981, 54, 2151.
(38) Shaw, G. J. J. Labelled Compd. Radiopharm. 1981, 18, 1641.

8654 J. Am. Chem. Soc., Vol. 120, No. 34, 1998
Takeuchi and Kashio
3H), 1.27 (t, J ) 7.3 Hz, 3H), 1.30-1.41 (m, 4H × 2), 2.17 (s, 3H),
2.23 (s, 3H), 2.81 (q, J ) 9.2 Hz, 1H × 2), 3.42 (d, J ) 9.9 Hz, 1H),
3.43 (d, J ) 9.2 Hz, 1H), 4.14 (q, J ) 6.9 Hz, 2H), 4.20 (q, J ) 6.9
Hz, 2H), 5.06 (d, J ) 10.0 Hz, 1H × 2,), 5.07 (d, J ) 17.5 Hz, 1H ×
2,), 5.53 (dt, J ) 17.5, 10.0 Hz, 1H), 5.61 (dt, J ) 17.5, 10.0 Hz, 1H);
13C NMR δ 13.6 (2C), 13.9 (2C), 19.8, 19.9, 29.2 (2C), 34.4 (2C),
43.6, 43.7, 61.0, 61.1, 65.0, 65.1, 117.1, 117.3, 138.0 (2C), 168.4, 168.6,
202.3 (2C).
(2C). Anal. Calcd for C16H20O4: C, 69.55; H, 7.29; O, 23.16.
Found: C, 69.82; H, 7.25.
Ethyl 3-Ethenyl-2-ethoxycarbonylnonanate (6c): 1H NMR δ 0.87
(t, J ) 6.9 Hz, 3H), 1.21-1.45 (m, 16H), 2.76 (qd, J ) 8.9, 3.6 Hz,
1H), 3.33 (d, J ) 8.9 Hz, 1H), 4.15 (q, J ) 6.9 Hz, 2H), 4.20 (q, J )
7.3 Hz, 2H), 5.06 (d, J ) 10.2 Hz, 1H), 5.07 (d, J ) 17.5 Hz, 1H),
5.65 (dt, J ) 17.2, 9.6 Hz, 1H); 13C NMR δ 13.9, 14.0 (2C), 22.5,
26.8, 28.9, 31.6, 32.2, 44.0, 57.0, 61.0, 61.1, 117.1, 138.2, 168,1, 168.3.
Anal. Calcd for C16H28O4: C, 67.57; H, 9.92; O, 22.50. Found: C,
67.36; H, 10.20.
Ethyl (E)-2-(1-Oxoethyl)-4-octenoate ((E)-4c):13b 1H NMR δ 0.86
(t, J ) 7.3 Hz, 3H), 1.26 (t, J ) 7.3 Hz, 3H), 1.35 (sextet, J ) 7.3 Hz,
2H), 1.95 (q, J ) 6.9 Hz, 2H), 2.21 (s, 3H), 2.53 (t, J ) 6.6 Hz, 2H),
3.47 (t, J ) 6.6 Hz, 1H), 4.19 (q, J ) 7.3 Hz, 2H), 5.33 (dt, J ) 15.5,
6.6 Hz, 1H), 5.51 (dt, J ) 15.5, 6.6 Hz, 1H); 13C NMR δ 13.4, 14.0,
20.0, 22.3, 31.1, 34.4, 59.8, 61.1, 125.4, 133.5, 169.3, 202.5.
Ethyl (Z)-2-(1-Oxoethyl)-4-octenoate ((Z)-4c): 1H NMR δ 0.90
(t, J ) 7.3 Hz, 3H), 1.27 (t, J ) 7.3 Hz, 3H), 1.37 (sextet, J ) 7.3 Hz,
2H), 2.04 (q, J ) 7.3 Hz, 2H), 2.23 (s, 3H), 2.59 (t, J ) 7.3 Hz, 2H),
3.45 (t, J ) 7.3 Hz, 1H), 4.19 (q, J ) 7.3 Hz, 2H), 5.27 (dt, J ) 10.9,
7.3 Hz, 1H), 5.47 (dt, J ) 10.9, 7.3 Hz, 1H); 13C NMR δ 13.6, 13.9,
19.8, 22.5, 25.9, 29.0, 59.5, 61.2, 124.7, 132.7, 169.3, 202.6. Anal.
Calcd for C12H20O3: C, 67.89; H, 9.50; O, 22.61. Found: C, 67.83;
H, 9.55.
Ethyl (E)-2-Ethoxycarbonyl-4-undecenoate ((E)-7c):39 1H NMR
δ 0.88 (t, J ) 6.9 Hz, 3H), 1.22-1.45 (m, 14H), 1.96 (q, J ) 6.6 Hz,
2H), 2.57 (t, J ) 6.6 Hz, 2H), 3.36 (t, J ) 7.6 Hz, 1H), 4.19 (q, J )
6.9 Hz, 4H), 5.36 (dt, J ) 15.2, 6.6 Hz, 1H), 5.52 (dt, J ) 15.5, 6.6
Hz, 1H); 13C NMR δ 14.0 (3C), 22.5, 28.7, 29.2, 31.6, 31.8, 32.4, 52.3,
61.2 (2C), 125.2, 133.9, 169.0 (2C).
Ethyl (Z)-2-Ethoxycarbonyl-4-undecenoate ((Z)-7c):40 1H NMR
δ 0.88 (t, J ) 6.9 Hz, 3H), 1.24-1.29 (m, 14H), 2.05 (q, J ) 6.6 Hz,
2H), 2.64 (t, J ) 7.6 Hz, 2H), 3.34 (t, J ) 7.6 Hz, 1H), 4.19 (q, J )
6.9 Hz, 4H), 5.30 (dt, J ) 10.9, 7.6 Hz, 1H), 5.48 (dt, J ) 10.9, 7.6
Hz, 1H); 13C NMR δ 14.0 (3C), 22.5, 26.6, 27.1, 28.9, 29.4, 31.7, 52.0,
61.2 (2C), 124.5, 133.1, 169.0 (2C).
Ethyl 3-Ethenyl-2-ethoxycarbonylundecanoate (6d): 1H NMR δ
0.87 (t, J ) 7.3 Hz, 3H), 1.21-1.45 (m, 20H), 2.76 (qd, J ) 9.2, 3.3
Hz, 1H), 3.33 (d, J ) 8.9 Hz, 1H), 4.15 (q, J ) 7.3 Hz, 2H), 4.19 (q,
J ) 7.3 Hz, 2H), 5.06 (dd, J ) 9.6, 2.0 Hz, 1H), 5.07 (dd, J ) 17.8,
2.0 Hz, 1H), 5.65 (dt, J ) 17.8, 9.6 Hz, 1H); 13C NMR δ 14.0 (3C),
22.6, 26.9, 29.2, 29.3, 29.4, 31.8, 32.2, 44.0, 57.0, 61.0, 61.2, 117.1,
138.2, 168,1, 168.3. Anal. Calcd for C18H32O4: C, 69.19; H, 10.32;
O, 20.48. Found: C, 68.96; H, 10.38.
Ethyl (E)-2-Ethoxycarbonyl-4-tridecenoate ((E)-7d):39 1H NMR
δ 0.88 (t, J ) 6.9 Hz, 3H), 1.14-1.42 (m, 18H), 1.96 (q, J ) 6.6 Hz,
2H), 2.57 (t, J ) 7.6 Hz, 2H), 3.36 (t, J ) 7.6 Hz, 1H), 4.19 (q, J )
7.3 Hz, 4H), 5.35 (dt, J ) 15.2, 6.6 Hz, 1H), 5.53 (dt, J ) 15.2, 6.6
Hz, 1H); 13C NMR δ 14.0 (3C), 22.6, 29.0, 29.2 (2C), 29.4, 31.8 (2C),
32.4, 52.2, 61.1 (2C), 125.1, 133.9, 168.9 (2C).
Ethyl (Z)-2-Ethoxycarbonyl-4-tridecenoate ((Z)-7d): 1H NMR δ
0.88 (t, J ) 6.9 Hz, 3H), 1.24-1.29 (m, 18H), 2.05 (q, J ) 7.3 Hz,
2H), 2.64 (t, J ) 7.3 Hz, 2H), 3.35 (t, J ) 7.6 Hz, 1H), 4.19 (q, J )
7.3 Hz, 4H), 5.30 (dt, J ) 10.9, 7.3 Hz, 1H), 5.48 (dt, J ) 10.9, 7.3
Hz, 1H); 13C NMR δ 14.0 (3C), 22.5, 26.6, 27.1, 29.2 (2C), 29.4, 29.5,
31.8, 52.0, 61.2 (2C), 124.5, 133.1, 169.0 (2C). Anal. Calcd for
C18H32O4: C, 69.19; H, 10.32; O, 20.48. Found: C, 69.24; H, 10.55.
Ethyl 2-Ethoxycarbonyl-5-methyl-4-hexenoate (6e):19 1H NMR
δ 1.26 (t, J ) 7.3 Hz, 6H), 1.64 (s, 3H), 1.68 (s, 3H), 2.59 (t, J ) 7.6
Hz, 2H), 3.32 (t, J ) 7.6 Hz, 1H), 4.19 (q, J ) 7.3 Hz, 4H), 5.07 (tq,
J ) 7.3, 1.7 Hz, 1H); 13C NMR δ 14.0 (2C), 17.6, 25.6, 27.5, 52.1,
61.1 (2C), 119.7, 134.7, 169.1 (2C).
Ethyl 2-Ethoxycarbonyl-3-ethenyl-2-methylhexanoate (3d):14a
1
Compound 3d could not be isolated in pure form. Partial H NMR
spectra was obtained from the mixture of 3d and (E)-4d. 1H NMR δ
5.05 (dd, J ) 16.8, 2.3 Hz, 1H), 5.09 (dd, J ) 10.2, 2.3 Hz, 1H), 5.57
(dt, J ) 16.8, 10.2 Hz, 1H).
Ethyl (E)-2-Ethoxycarbonyl-2-methyl-4-octenoate ((E)-4d):14a 1
H
NMR δ 0.87 (t, J ) 7.3 Hz, 3H), 1.24 (t, J ) 7.3 Hz, 6H), 1.31-1.40
(m, 5H), 1.96 (q, J ) 6.9 Hz, 2H), 2.55 (d, J ) 6.9 Hz, 2H), 4.17 (q,
J ) 7.3 Hz, 4H), 5.29 (dt, J ) 15.2, 6.9 Hz, 1H), 5.50 (dt, J ) 15.2,
6.9 Hz, 1H); 13C NMR δ 13.5, 14.0 (2C), 19.6, 22.4, 34.6, 38.8, 53.7,
61.0 (2C), 122.8, 135.1, 172.0 (2C).
Ethyl (Z)-2-Ethoxycarbonyl-2-methyl-4-octenoate ((Z)-4d):14a 1
H
NMR δ 0.90 (t, J ) 7.3 Hz, 3H), 1.24 (t, J ) 7.3 Hz, 6H), 1.31-1.41
(m, 5H), 2.02 (q, J ) 7.6 Hz, 2H), 2.63 (d, J ) 7.6 Hz, 2H), 4.18 (q,
J ) 7.3 Hz, 4H), 5.26 (dt, J ) 10.9, 7.6 Hz, 1H), 5.53 (dt, J ) 10.9,
7.6 Hz, 1H); 13C NMR δ 13.9, 14.0 (2C), 19.5, 22.6, 29.3, 33.1, 53.4,
61.0 (2C), 123.0, 133.6, 172.0 (2C).
Ethyl 2-Ethoxycarbonyl-3-methyl-4-pentenoate (6a):13b 1H NMR
δ 1.11 (d, J ) 6.6 Hz, 3H), 1.25 (t, J ) 7.3 Hz, 3H), 1.27 (t, J ) 7.3
Hz, 3H), 2.95 (sextet, J ) 7.6 Hz, 1H), 3.27 (d, J ) 8.9 Hz, 1H), 4.17
(q, J ) 7.3 Hz, 2H), 4.20 (q, J ) 7.3 Hz, 2H), 5.01 (dd, J ) 10.2, 0.7
Hz, 1H), 5.07 (dd, J ) 17.5, 0.7 Hz, 1H), 5.65 (dt, J ) 17.2, 9.9 Hz,
1H); 13C NMR δ 14.0 (2C), 17.8, 37.8, 57.6, 61.0, 61.1, 115.2, 139.7,
168.1, 168.2.
Ethyl (E)-2-Ethoxycarbonyl-4-hexenoate ((E)-7a):13b 1H NMR δ
1.26 (t, J ) 6.9 Hz, 6H), 1.63 (dd, J ) 6.3, 1.0 Hz, 3H), 2.56 (t, J )
6.6 Hz, 2H), 3.36 (t, J ) 7.6 Hz, 1H), 4.19 (q, J ) 6.9 Hz, 4H), 5.38
(dtq, J ) 15.2, 6.6, 1.3 Hz, 1H), 5.55 (dq, J ) 15.2, 6.3 Hz, 1H); 13C
NMR δ 14.0 (2C), 17.7, 31.8, 52.1, 61.0, 61.1, 126.5, 128.1, 168.9
(2C).
Ethyl 2-Ethoxycarbonyl-3,3-dimethyl-4-pentenoate (7e):19 1H
NMR δ 1.24 (s, 6H), 1.26 (t, J ) 7.3 Hz, 6H), 3.32 (s, 1H), 4.17 (q,
J ) 7.3 Hz, 4H), 5.01 (dd, J ) 10.6, 1.0 Hz, 1H), 5.03 (dd, J ) 17.5,
1.0 Hz, 1H), 6.06 (dd, J ) 17.5, 10.6 Hz, 1H); 13C NMR δ 14.0 (4C),
25.0, 38.7, 60.8 (2C), 112.0, 144.8, 167.8 (2C).
Ethyl 2-Ethoxycarbonyl-3-phenyl-4-pentenoate (6b):13b 1H NMR
δ 1.26 (t, J ) 7.3 Hz, 3H), 1.27 (t, J ) 7.3 Hz, 3H), 3.83 (d, J ) 11.2
Hz, 1H), 4.11 (dd, J ) 11.2, 8.3 Hz, 1H), 4.20 (q, J ) 7.3 Hz, 4H),
5.06 (d, J ) 9.2 Hz, 1H), 5.11 (d, J ) 15.8 Hz, 1H), 6.00 (ddd, J )
15.8, 9.2, 8.3 Hz, 1H), 7.17-7.31 (m, 5H); 13C NMR δ 13.6 (2C),
49.5, 57.2, 61.1 (2C), 116.2, 126.9, 127.9 (2C), 128.4 (2C), 137.8, 139.9,
167.6 (2C).
Methyl 2-Methoxycarbonyl-3,3-dimethyl-4-pentenoate (7eb):19 1
H
NMR δ 1.24 (s, 6H), 3.38 (s, 1H), 3.70 (s, 6H), 5.01 (dd, J ) 10.1, 1.0
Hz, 1H), 5.03 (dd, J ) 18.3, 1.0 Hz, 1H), 6.04 (dd, J ) 18.3, 10.1 Hz,
1H); 13C NMR δ 24.9 (2C), 38.8, 51.9 (2C), 60.5, 112.2, 144.6, 168.2
(2C).
Ethyl 3-Ethenyl-2-ethoxycarbonyl-3-methylheptanoate (7f): 1H
NMR δ 0.88 (t, J ) 6.9 Hz, 3H), 1.17-1.31 (m, 13H), 1.47-1.60 (m,
2H), 3.41 (s, 1H), 4.15 (q, J ) 6.9 Hz, 2H), 4.17 (q, J ) 6.9 Hz, 2H),
4.99 (dd, J ) 17.5, 1.0 Hz, 1H), 5.08 (dd, J ) 10.9, 1.0 Hz, 1H), 5.99
(dd, J ) 17.5, 10.9 Hz, 1H); 13C NMR δ 13.9, 14.0 (2C), 19.8, 23.1,
26.0, 38.8, 42.0, 60.0, 60.7, 60.8, 113.3, 143.3, 167.8 (2C). Anal. Calcd
for C15H26O4: C, 66.64; H, 9.69; O, 23.67. Found: C, 66.40; H, 9.88.
Ethyl 3-Ethenyl-2-ethoxycarbonyl-3,7-dimethyl-6-octenoate (7g):
19 1H NMR δ 1.24 (t, J ) 6.9 Hz, 3H), 1.26 (t, J ) 6.9 Hz, 3H), 1.27
Ethyl (E)-2-Ethoxycarbonyl-5-phenyl-4-pentenoate ((E)-7b):13b 1
H
NMR δ 1.25 (t, J ) 7.3 Hz, 3H), 1.27 (t, J ) 7.3 Hz, 3H), 2.80 (td, J
) 7.3, 1.3 Hz, 2H), 3.49 (t, J ) 7.3 Hz, 1H), 4.20 (q, J ) 7.3 Hz, 4H),
6.15 (dt, J ) 15.8, 7.3 Hz, 1H), 6.47 (d, J ) 15.8 Hz, 1H), 7.16-7.34
(m, 5H); 13C NMR δ 14.0 (2C), 32.1, 51.9, 61.3 (2C), 125.5, 126.1
(2C), 127.2, 128.4 (2C), 132.7, 137.0, 168.7 (2C).
Ethyl (Z)-2-Ethoxycarbonyl-5-phenyl-4-pentenoate ((Z)-7b): 1H
NMR δ 1.22 (t, J ) 6.9 Hz, 3H), 1.28 (t, J ) 6.9 Hz, 3H), 2.94 (td, J
) 7.3, 1.7 Hz, 2H), 3.44 (t, J ) 7.3 Hz, 1H), 4.17 (q, J ) 6.9 Hz, 2H),
4.20 (q, J ) 6.9 Hz, 2H), 5.60 (dt, J ) 11.9, 7.3 Hz, 1H), 6.51 (d, J
) 11.9 Hz, 1H), 7.17-7.37 (m, 5H); 13C NMR δ 13.9 (2C), 41.5, 52.0,
61.3 (2C), 126.8, 127.9, 128.1 (2C), 128.6 (2C), 131.4, 137.9, 168.8
(39) Nii, H.; Furukawa, K.; Iwakiri, M. Nippon Kagaku Zasshi 1971,
92, 1214.
(40) Vig, O. P.; Sharma, M. L.; Taneja, K. C.; Malik, N. Indian J. Chem.
1981, 20B, 863.

Iridium Complex-Catalyzed Allylic Alkylations
J. Am. Chem. Soc., Vol. 120, No. 34, 1998 8655
(s, 3H), 1.50-1.61 (m, 5H), 1.66 (s, 3H), 1.90 (q, J ) 7.6 Hz, 2H),
3.41 (s, 1H), 4.15 (q, J ) 6.9 Hz, 2H), 4.17 (q, J ) 6.9 Hz, 2H), 5.01
(dd, J ) 17.5, 1.0 Hz, 1H), 5.03 (m, 1H), 5.10 (dd, J ) 10.9, 1.0 Hz,
1H), 6.00 (dd, J ) 17.5, 10.9 Hz, 1H); 13C NMR δ 14.0 (2C), 17.5,
19.7, 22.6, 25.6, 39.0, 42.0, 59.9, 60.8, 60.9, 113.3, 124.1, 131.4, 143.1,
167.8 (2C).
Methyl 3-Ethenyl-2-methoxycarbonyl-3,7-dimethyl-6-octenoate
(7gb):10f 1H NMR δ 1.27 (s, 3H), 1.49-1.59 (m, 5H), 1.66 (s, 3H),
1.90 (q, J ) 7.3 Hz, 2H), 3.46 (s, 1H), 3.68 (s, 3H), 3.70 (s, 3H), 5.01
(dd, J ) 17.5, 1.0 Hz, 1H), 5.03 (m, 1H), 5.11 (dd, J ) 10.9, 1.0 Hz,
1H), 5.98 (dd, J ) 17.5, 10.9 Hz, 1H); 13C NMR δ 17.5, 19.6, 22.6,
25.6, 39.0, 42.1, 51.9, 52.0, 59.8, 113.8, 124.0, 131.5, 142.9, 168.1,
168.2.
tet, J ) 7.6 Hz, 2H), 2.11 (q, J ) 7.3 Hz, 2H), 2.58-2.65 (m, 4H),
3.34 (t, J ) 7.6 Hz, 1H), 4.18 (q, J ) 6.9 Hz, 4H), 5.34 (dt, J )
10.9, 7.3 Hz, 1H), 5.50 (dt, J ) 10.9, 7.3 Hz, 1H), 7.13-7.29 (m,
5H); 13C NMR δ 13.9 (2C), 26.6, 26.7, 31.1, 35.3, 51.9, 61.2, 61.3,
125.0, 125.6, 128.2 (2C), 128.3 (2C), 132.4, 142.2, 166.5, 168.9. Anal.
Calcd for C19H26O4: C, 71.67; H, 8.23; O, 20.10. Found: C, 71.78;
H, 8.43.
Dimethyl (Z)-(5-Carbomethoxy-1-cyclohexen-3-yl)malonate (17):
14b
1H NMR δ 1.46 (q, J ) 12.5 Hz, 1H), 2.09-2.18 (m, 1H), 2.20-
2.33 (m, 2H), 2.61-2.70 (m, 1H), 2.99-3.03 (m, 1H), 3.30 (d, J )
8.9 Hz, 1H), 3.69 (s, 3H), 3.75 (s, 6H), 5.53 (d, J ) 9.6 Hz, 1H), 5.78
(ddt, J ) 10.2, 5.0, 2.3 Hz, 1H); 13C NMR δ 27.5, 29.3, 35.9, 39.3,
51.6, 52.3 (2C), 56.3, 127.2 (2C), 168.4 (2C), 175.3.
Ethyl 2-Ethoxycarbonyl-4-methyl-4-pentenoate (11):9i 1H NMR
δ 1.26 (t, J ) 7.3 Hz, 6H), 1.74 (s, 3H), 2.61 (d, J ) 7.9 Hz, 2H), 3.57
(t, J ) 7.9 Hz, 1H), 4.19 (q, J ) 7.3 Hz, 4H), 4.73 (s, 1H), 4.78 (s,
1H); 13C NMR δ 13.9 (2C), 22.1, 36.4, 50.4, 61.2 (2C), 112.1, 141.6,
168.9 (2C).
Isomerization of (Z)-4a in the Presence of Diethyl Sodiomalonate
(2a) and an Ir Catalyst. A 23:4:73 mixture of 3a, (E)-4a, (Z)-4a
(485 mg, 2.0 mmol), triphenyl phosphite (49.6 mg, 0.16 mmol), and
[Ir(COD)Cl]2 (26.9 mg, 0.04 mmol) was stirred in 5.0 mL of THF under
Ar atmosphere. In a separate flask, diethyl malonate (640 mg, 4.0
mmol) was added to a slurry of hexane-washed sodium hydride (96
mg, 4.0 mmol) in 5.0 mL of THF. The resulting clear solution was
added to the former by a syringe, and the combined mixture was stirred
for 4 h. The reaction mixture was partitioned between ether and water.
The organic layer was separated, and the aqueous layer was extracted
with ether. The combined organic layer was analyzed by GLC. The
ratio of 3a to (E)-4a to (Z)-4a was 23:17:60.
Ethyl 2-Ethenyl-2-ethoxycarbonyl-6-phenylhexanoate (14f): 1H
NMR δ 1.22 (t, J ) 7.3 Hz, 3H), 1.23 (t, J ) 7.3 Hz, 3H), 1.32-1.76
(m, 4H), 2.48-2.68 (m, 2H), 2.80 (qd, J ) 9.6, 3.3 Hz, 1H), 3.33 (d,
J ) 8.9 Hz, 1H), 4.14 (q, J ) 7.3 Hz, 2H), 4.17 (q, J ) 7.3 Hz, 2H),
5.07 (dd, J ) 9.6, 2.0 Hz, 1H), 5.08 (d, 1H, J ) 17.2 Hz, 1H), 5.63
(dt, 1H, J ) 17.2, 9.6 Hz, 1H), 7.13-7.28 (m, 5H); 13C NMR δ 13.9
(2C), 28.8, 31.8, 35.5, 43.9, 56.9, 61.2 (2C), 61.3, 117.4, 125.6, 128.1
(2C), 128.2 (2C), 137.9, 142.2, 168.0, 168.2. Anal. Calcd for
C19H26O4: C, 71.67; H, 8.23; O, 20.10. Found: C, 71.85; H, 8.18.
Acknowledgment. This work was supported by Grant-in-
Aid for Scientific Research on Priority Areas (No. 283,
“Innovative Synthetic Reactions”) from the Ministry of Educa-
tion, Science, Sports and Culture, Government of Japan. We
thank Kuraray Company Ltd. for financial support. We thank
Prof. T. Ohta for measuring the 31P-NMR spectra.
Ethyl (E)-2-Ethoxycarbonyl-8-phenyl-4-octenoate ((E)-15f):41 1
H
NMR δ 1.25 (t, J ) 6.9 Hz, 3H), 1.27 (t, J ) 6.9 Hz, 3H), 1.65 (quintet,
J ) 7.6 Hz, 2H), 2.01 (q, J ) 6.9 Hz, 2H), 2.54-2.60 (m, 4H), 3.37
(t, J ) 7.6 Hz, 1H), 4.17 (q, J ) 7.3 Hz, 2H), 4.18 (q, J ) 7.3 Hz,
2H), 5.38 (dt, J ) 15.2, 6.9 Hz, 1H), 5.55 (dt, J ) 15.2, 6.6 Hz, 1H),
7.14-7.29 (m, 5H); 13C NMR δ 13.9, 14.0, 30.9 (2C), 31.8, 35.1, 52.2,
61.2 (2C), 125.6, 125.8, 128.2 (2C), 128.3 (2C), 133.3, 142.3, 168.9
(2C).
Supporting Information Available: 31P NMR spectra of
the reaction of [Ir(COD)Cl]2 with P(OPh)3 in d8-THF (3 pages,
print/PDF). See any current masthead page for ordering
information and Web access instructions.
Ethyl (Z)-2-Ethoxycarbonyl-8-phenyl-4-octenoate ((Z)-15f): 1H
NMR δ 1.25 (t, J ) 6.9 Hz, 3H), 1.27 (t, J ) 6.9 Hz, 3H), 1.67 (quin-
(41) Larock, R. C.; Lu, Y.; Bain, A. C.; Russell, C. E. J. Org. Chem.
1991, 56, 4589.
JA981560P