Nickel-catalyzed addition of organoboronates to 1,2-dienes and the corresponding three-component reaction with an alkyne

Article abstract of DOI:10.1002/adsc.200505445

A Ni(cod)₂-aminophosphine complex catalyzed the addition of aryl- and alkenylboronates to 1,2-dienes to give the hydroarylation and hydroalkenylation products of the 1,2-dienes, whereas the hydroarylation products of a 1,2-diene and an alkyne w

Full text of DOI:10.1002/adsc.200505445

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DOI: 10.1002/adsc.200505445
Nickel-Catalyzed Addition of Organoboronates to 1,2-Dienes and
the Corresponding Three-Component Reaction with an Alkyne
Go Takahashi,a Eiji Shirakawa,b,* Teruhisa Tsuchimoto,a Yusuke Kawakamia
a
Graduate School of Materials Science, Japan Advanced Institute of Science and Technology, Asahidai, Nomi, Ishikawa
923-1292, Japan
b
Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
Fax: (þ81)-75-753-3988, e-mail: shirakawa@kuchem.kyoto-u.ac.jp
Received: November 15, 2005; Accepted: February 28, 2006
Supporting Information for this article is available on the WWW under http://asc.wiley-vch.de/home/.
Abstract: A Ni(cod)2–aminophosphine complex cat-
alyzed the addition of aryl- and alkenylboronates
to 1,2-dienes to give the hydroarylation and hydroal-
kenylation products of the 1,2-dienes, whereas the
hydroarylation products of a 1,2-diene and an alkyne
were obtained with a Ni(cod)2–PPh3 catalyst.
(1a) to 4,5-nonadiene (2a). Thus, treatment of 1a and 2a
with Ni(cod)2 (5 mol %), 1-dimethylamino-3-(diphenyl-
phosphino)propane (AP: 5 mol %) and H2O (1.0 equiv.)
in NMP at 808C for 24 h gave 6-(p-tolyl)-4-nonene (3a)
in 82% yield with a high stereoselectivity (E:Z¼91:9),
whereas a regioisomer, (Z)-5-(p-tolyl)-4-nonene (4a),
was generated only in 1% yield [Eq. (1) and entry 1 of
Table 1]. The use of triphenylphosphine (10 mol %) as
a ligand instead of AP gave no 3a but rather a mixture
of 1:2 adducts of 1a with 2a in low yields. Bisphosphine
ligands (5 mol %) in combination with Ni(cod)2
(5 mol %) were also ineffective, giving no hydroaryla-
Keywords: alkynes; allenes; arylboronates; hydroal-
kenylation; hydroarylation; nickel
The transition metal-catalyzed addition of organoboron tion product or 1:2 adducts. The scope of the hydroary-
compounds to carbon–carbon unsaturated bonds has re- lation of 2a was next examined. High yields and high
cently attracted much attention due mainly to the high stereoselectivities were observed also in the addition
chemoselectivity and low toxicity of organoboron com- of arylboronates having an electron-donating or -with-
pounds. In particular, rhodium catalysts have establish- drawing group (entries 2 and 3). The bulky 1,3-disubsti-
ed their place since the pioneering report on the conju- tuted allene 2b also accepted the addition of 1a with per-
gate addition of arylboronic acids to enones by Miyaura fect regio- and stereoselectivities (entry 4). Tetramethy-
and co-workers in 1997,[1] which was followed by reports lallene (2c) underwent the hydroarylation with various
on the addition to other Michael acceptors,[1c, d] al- arylboronates, completely controlling the regiochemis-
kenes[2] and alkynes.[3] We reported in 2001 the nickel- try (entries 5–7). These di- and tetrasubstituted allenes
catalyzed hydroarylation of alkynes with arylboron reacted also with a styryl boronate albeit in low yields
compounds as the first example of the group 10 metal- (entries 8 and 9). The trisubstituted allene 2d also par-
catalyzed addition of organoboron compounds to car- ticipated in the hydroarylation with 1a to give a regioiso-
bon–carbon unsaturated bonds.[4] The nickel catalysis meric mixture of hydroarylation products in high yields
was further applied to the addition of aryl- and alkenyl- [Eq. (2)]. Unfortunately, the addition to monosubstitut-
boronates to 1,3-dienes[5] and aldehydes.[6] On the other ed allenes such as 1,2-heptadiene gave a complex mix-
hand, the palladium-catalyzed addition of organoboron ture including 1:2 adducts of 1a to the allene.
compounds to alkynes[7] or 1,2-dienes[8,9] was reported
by Oh as well as Ma in 2003, although the addition to
1,2-dienes is applicable mainly to heteroatom-contain-
ing 1,2-dienes and relatively electron-rich organoboron
compounds. Here we report the nickel-catalyzed addi-
tion of organoboronates to di-, tri- and tetrasubstituted
allenes as well as the hydroarylation of 1,2-dienes and al-
kynes through a three-component reaction.[10–12]
We first investigated suitable conditions for the nick-
el-catalyzed addition of 2-(p-tolyl)-1,3,2-dioxaborinane
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837

Go Takahashi et al.
Product
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Table 1. Nickel-catalyzed addition of organoboronates to 1,2-dienes.[a]
Entry
R1
R2
R3
Yield [%][b]
E :Z[c]
91: 9[d]
1
2
3
4
5
6
7
8
9
4-Me-C6H4 (1a)
4-MeO-C6H4 (1b)
4-Ac-C6H4 (1c)
4-Me-C6H4 (1a)
4-Me-C6H4 (1a)
4-MeO-C6H4 (1b)
4-Ac-C6H4 (1c)
styryl (1d)
Pr
Pr
Pr
i-Pr
Me
Me
Me
Pr
H (2a)
H (2a)
H (2a)
H (2b)
Me (2c)
Me (2c)
Me (2c)
H (2a)
Me (2c)
82
77
85
83
94
79
84
42
37
3a
3b
3c
3d
3e
3f
92: 8[e]
93: 7
>99: 1
–
–
–
>99: 1
–
3g
3h
3i
styryl (1d)
Me
[a]
The reaction was carried out in NMP (0.45 mL) at 808C for 24 h using an organoboronate (0.30 mmol) and a 1,2-diene
(0.90 mmol) in the presence of Ni(cod)2 (15 mmol), 1-dimethylamino-3-(diphenylphosphino)propane (AP: 15 mmol) and
H2O (0.30 mmol).
[b]
[c]
[d]
[e]
Isolated yield based on the arylboronate.
1
Determined by H NMR.
(Z)-5-(p-Tolyl)-4-nonene (4a) was also produced in 1% yield.
(Z)-5-(4-Methoxyphenyl)-4-nonene (4b) was also produced in 2% yield.
In the present nickel-catalyzed reaction of arylboro-
nates with the aid of H2O, aryl groups add to a terminal
sp2-carbon atom of allenes, in contrast to which arylbor-
onic acids attack the central allene carbon in the pres-
ence of a palladium catalyst and acetic acid as reported
by Oh or Ma.[8,9] The difference in regioselectivities
should imply that these reactions proceed through dif-
ferent catalytic cycles. Ma and co-workers have recently
clarified the mechanism of the palladium-catalyzed hy-
The present catalyst system was found to be applicable droarylation using ESI-FT-MS analysis, where the cata-
also to the three-component reaction between an aryl- lytic cycle includes oxidative addition of acetic acid to a
boronate, a 1,2-diene and an alkyne. Treatment of p-tol- palladium(0) complex.[9b] On the other hand, H2O in the
ylboronate 1a, 4,5-nonadiene (2a) and 4-octyne (7) with addition to organoboronates seem not to undergo oxi-
Ni(cod)2 (5 mol %), AP (5 mol %) and H2O (1.0 equiv.) dative addition to a nickel(0) complex in our reaction
in NMP at 808C for 24 h gave a three-component reac- conditions.[5] Thus, based on the mechanism of the nick-
tion product, (4E,6Z)-5-propyl-6-[1-(p-tolyl)but-1-yl]- el-catalyzed addition of organoboronates to 1,3-di-
4,6-decadiene (8a), in 54% yield in addition to10% yield enes,[5] a nickel(0) complex may first react with 1,2-di-
of 3a [Eq. (3)]. Use of triphenylphosphine as a ligand in- enes and/or alkynes. Possible catalytic cycles exempli-
stead of AP slightly increased the yield of 8a. 2,6-Di- fied by the reaction of 2-(p-tolyl)-1,3,2-dioxaborinane
methyl-3,4-heptadiene (2b) also underwent the three- (1a), 4,5-nonadiene (2a) and 4-octyne (7) are shown in
component reaction with 1a and alkyne 7.
Scheme 1. In the addition to 2a (Cycle A), oxidative cyc-
lization of 2a to a nickel(0) complex gives nickelacyclo-
propane 9, which reacts with the 1a–H2O complex 10,
making bonds with the p-tolyl group and a proton of
10 at Ni and the C(sp2) of nickelacycle 9, respectively.
The resulting anti-p-allylnickel complex 11 isomerizes
to the thermodynamically more stable syn-isomer 12,
which undergoes reductive elimination to give (E)-3a
as the main product and regenerate the nickel(0) com-
plex. In contrast, in the presence of 4-octyne (7), nickel-
acyclopropane 9 accepts insertion of 7 to give nickelacy-
clopentene 13 (Cycle B).[13] Complex 10 reacts with 13,
2
ꢀ
cleaving the Ni C(sp ) bond to give p-allylnickel com-
plex 14. After isomerization from the anti- to the syn-
p-allylnickel complex 15, reductive elimination gives
8a and the nickel(0) complex.
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Addition of Organoboronates to 1,2-Dienes
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Scheme 1. Proposed catalytic cycles A and B.
none ketyl just prior to use. 1,2-Dienes, 4-octyne and
NMP were degassed through four freeze-thaw cycles just be-
fore use.
In conclusion, we have disclosed that nickel(0) com-
plexes are effective catalysts for the addition of organo-
boron compounds to 1,2-dienes, where hydroarylation
and hydroalkenylation products of 1,2-dienes in addi-
tion to the corresponding three-component reaction
product with an alkyne are obtained. Further studies
on details of the reaction mechanism as well as applica-
tion of the reaction to other substrates are in progress.
Nickel-Catalyzed Hydroarylation and
hydroalkenylation of 1,2-Dienes with
Organoboronates; General Procedure
To a mixture of an organoboronate (0.30 mmol), a 1,2-diene
(0.90 mmol) and 1-(dimethylamino)-3-(diphenylphosphino)-
propane (8.1 mg, 30 mmol) were added successively an NMP
(0.45 mL) solution of Ni(cod)2 (4.1 mg, 15 mmol) and water
(5.4 mg, 0.30 mmol). After the mixture had been stirred at
808C for 24 h, the resulting mixture was treated with saturated
NaHCO3 aqueous solution and extracted with diethyl ether
(10 mLꢁ3). The combined organic layer was washed with
brine (10 mL), and then dried over anhydrous magnesium sul-
fate. Filtration and evaporation of the solvent followed by col-
umn chromatography on silica gel (hexane–ethyl acetate) gave
the corresponding products. The results are summarized in Ta-
ble 1.
Experimental Section
General Remarks
All manipulations of oxygen- and moisture-sensitive materials
were conducted with standard Schlenk techniques under a ni-
trogen atmosphere. Column chromatography was performed
using silica gel 60N purchased from Kanto Chemicals. Nuclear
magnetic resonance spectra were taken on a Varian Gemini
2000 (1H, 300 MHz; 13C, 75 MHz) spectrometer using tetrame-
thylsilane (1H and 13C) as an internal standard. High-resolution
mass spectra were obtained with a Bruker Bio APEX 70e spec-
trometer. Unless otherwise noted, reagents were commercially
available and used without further purification. Anhydrous
NMP was purchased from Kanto Chemicals. Bis(1,5-cycloocta-
diene)nickel was purchased from Kanto Chemicals or Strem
and recrystallized from toluene/1,5-cyclooctadiene (50:1). Or-
ganoboronic acids were purchased from Aldrich Chemical Co.
4-Octyne was purchased from Kanto Chemicals and fractional-
ly distilled. Grignard reagents were purchased from Kanto
Chemicals. CuBr was washed with methanol prior to use. Di-
ethyl ether and THF were distilled from sodium/benzophe-
Nickel-Catalyzed Tandem Hydroarylation of 1,2-
Dienes and 4-Octyne with 2-(p-Tolyl)-1,3,2-
dioxaborinane; General Procedure
To a mixture of 2-(p-tolyl)-1,3,2-dioxaborinane (52.8 mg,
0.300 mmol), a 1,2-diene (0.60 or 0.90 mmol), 4-octyne
(0.26 mL, 1.8 mmol) and PPh3 (7.9 mg, 30 mmol) were added
an NMP (0.45 mL) solution of Ni(cod)2 (4.1 mg, 15 mmol)
and water (5.4 mg, 0.30 mmol), successively. After the mixture
Adv. Synth. Catal. 2006, 348, 837 – 840
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asc.wiley-vch.de
839

Go Takahashi et al.
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had been stirred at 80 or 608C for 24 h, the resulting mixture
was treated with saturated NaHCO3 aqueous solution and ex-
tracted with diethyl ether (10 mLꢁ3). The combined organic
layer was washed with brine (10 mL), and then dried over an-
hydrous magnesium sulfate. Filtration and evaporation of the
solvent followed by column chromatography on silica gel (hex-
ane–ethyl acetate) gave the corresponding products. The re-
sults are summarized in Eq. (3).
[7] a) C. H. Oh, H. H. Jung, K. S. Kim, N. Kim, Angew.
Chem. Int. Ed. 2003, 42, 805–808; 7b) N. Kim, K. S.
Kim, A. K. Gupta, C. H. Oh, Chem. Commun. 2004,
618–619.
[8] C. H. Oh, T. W. Ahn, V. R. Reddy, Chem. Commun.
2003, 2622–2623.
[9] Ma and co-workers also have reported the hydroaryla-
tion of 1,2-dienes, where a catalytic or stoichiometric
amount of acetic acid acts as an indispensable activator,
see: a) S. Ma, N. Jiao, L. Ye, Chem. Eur. J. 2003, 9, 6049–
6056; b) R. Qian, H. Guo, Y. Liao, Y. Gou, S. Ma, Angew.
Chem. Int. Ed. 2005, 44, 4771–4774.
References and Notes
[1] a) M. Sakai, H. Hayashi, N. Miyaura, Organometallics
1997, 16, 4229–4231; for the first asymmetric version of
the addition to enones, see: b) Y. Takaya, M. Ogasawara,
T. Hayashi, M. Sakai, N. Miyaura, J. Am. Chem. Soc.
1998, 120, 5579–5580; for reviews, see: c) K. Fagnou,
M. Lautens, Chem. Rev. 2003, 103, 169–196; d) T. Haya-
shi, K. Yamasaki, Chem. Rev. 2003, 103, 2829–2844.
[2] a) K. Oguma, M. Miura, T. Satoh, M. Nomura, J . Am.
Chem. Soc. 2000, 122, 10464–10465; b) M. Lautens, A.
Roy, K. Fukuoka, K. Fagnou, B. Martin-Matute, J. Am.
Chem. Soc. 2001, 123, 5358–5359.
[3] T. Hayashi, K. Inoue, N. Taniguchi, M. Ogasawara, J.
Am. Chem. Soc. 2001, 123, 9918–9919.
[4] E. Shirakawa, G. Takahashi, T. Tsuchimoto, Y. Kawaka-
mi, Chem. Commun. 2001, 2688–2689.
[5] E. Shirakawa, G. Takahashi, T. Tsuchimoto, Y. Kawaka-
mi, Chem. Commun. 2002, 2210–2211.
[10] An intramolecular version of the reaction using a palla-
dium catalyst, 1,6-allenynes and arylboronic acids has re-
cently been published: A. K. Gupta, C. Y. Rhim, C. H.
Oh, Tetrahedron Lett. 2005, 46, 2247–2250.
[11] We have already reported the nickel-catalyzed tandem
carbostannylation of 1,2-dienes and alkynes with alky-
nylstannanes, see: E. Shirakawa, Y. Yamamoto, Y. Na-
kao, S. Oda, T. Tsuchimoto, T. Hiyama, Angew. Chem.
Int. Ed. 2004, 43, 3448–3451.
[12] For a recent review on 1,2-dienes, see: N. Krause, S.
Hashmi, Modern Allene Chemistry, John Wiley & Sons,
Weinheim, 2004.
[13] As formation of nickelacyclopentene 13 should require
more coordination sites than nickelacyclopropane 9,
monodentate PPh3 is more effective than bidentate ami-
nophosphine AP in the three-component reaction.
[6] G. Takahashi, E. Shirakawa, T. Tsuchimoto, Y. Kawaka-
mi, Chem. Commun. 2005, 1459–1461.
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Adv. Synth. Catal. 2006, 348, 837 – 840