Three-component coupling reaction: Palladium-catalyzed coupling of norbornadiene and iodonium salts or diazonium salts with organostannanes, alkynes, and sodium tetraphenylborate

Article abstract of DOI:10.1055/s-1998-6086

A ternary coupling of norbornadiene and iodonium salts or diazonium salts with organostannanes, alkynes, or sodium tetraphenylborate catalyzed by ligand-free palladium was accomplished at ambient temperature under mild conditions.

Full text of DOI:10.1055/s-1998-6086

SYNTHESIS
September 1998
1249
Three-Component Coupling Reaction: Palladium-Catalyzed Coupling of
Norbornadiene and Iodonium Salts or Diazonium Salts with Organostannanes,
Alkynes, and Sodium Tetraphenylborate
Suk-Ku Kang,* Jae-Sun Kim, Sang-Chul Choi, Kwon-Ho Lim
Department of Chemistry, Sung Kyun Kwan University, Natural Science Campus, Suwon 440-746, Korea
Fax +82 (331) 2907079; E-mail: skkang@ chem.skku.ac.kr
Received 4 January 1998; revised 3 March 1998
Abstract: A ternary coupling of norbornadiene and iodonium
summarized in Table 1. When norbornadiene (1) (2 equiv)
was reacted with diphenyliodonium tetrafluoroborate (1
equiv) in anhydrous DMF in the presence of Pd(OAc)2 (5
mol %) at room temperature followed by addition of tribu-
tylphenylstannane (1 equiv) in DMF slowly via a syringe
pump for 1 h and then stirred for 1 hour at room temperature,
the coupled product 8a was obtained in 84% yield (entry 1
in Table 1). By the same method, alkynyltributylstannane
4b was also coupled to give compound 9 (entry 2). Alterna-
tively, norbornadiene (1) was also coupled with phenylacet-
ylene (5) to afford 9 in 76% yield (entry 3). This is the com-
bination of Heck and Sonogashira reactions. Heck addition
followed by coupling with a nucleophile was accomplished
with sodium tetraphenylborate (entry 4). Sodium tetraphen-
ylborate (6) was coupled to norbornadiene (1) with diphen-
yliodonium tetrafluoroborate (2) to afford 8a in 72% yield.
However, Heck addition of 2 to norbornadiene (1) followed
by Suzuki-type addition gave the coupled product 8a in a
low yield (38%) (entry 5). It is notable that biscarbonylative
ternary coupling was carried out at atmospheric pressure of
CO with NaBPh4 (6) to afford diketone 107 in 73% yield
(entry 6). The use of PhB(OH)2 (1) instead of NaBPh4 (6)
afforded diketone 10 in 32% yield (entry 7).
salts or diazonium salts with organostannanes, alkynes, or sodium
tetraphenylborate catalyzed by ligand-free palladium was accom-
plished at ambient temperature under mild conditions.
Key words: norbornadiene, aryldiazonium tetrafluoroborates,
sodium tetraphenylborate, organostannanes, 3-component cou-
pling, palladium-catalyzed coupling, Heck reaction
Combination of the Heck-type arylation of olefins with
palladium-catalyzed cross-coupling reactions (the so
called three-component coupling reaction or ternary cou-
pling reaction) is an important methodology to construct
complex molecules directly,1 especially to construct the
prostaglandin analogues. However, there was a restriction
in the applicable olefins which have high insertion and no
effect in β-elimination. Previously the palladium-cata-
lyzed three-component coupling of organic halides and
organostannanes, alkynes, or tetraphenylborate ion was
restricted to norbornene. Kosugi et al.2 reported the cou-
pling of norbornadiene in the ternary coupling with orga-
nostannanes. Recently, Kosugi et al.3 reported that 1,3-di-
oxole was utilized as the olefin in this coupling. In con-
nection with our programs to utilize iodonium salts and
diazonium salts in palladium-catalyzed cross-coupling,4
we have investigated the ternary coupling of iodonium
salts5 and diazonium salts6 with norbornadiene in the
presence of organostannanes, alkynes, and sodium tet-
raphenylborate. Here, we wish to report the mild ternary
coupling and carbonylative coupling of norbornadiene
and iodonium or diazonium salt with organostannanes,
alkynes, and sodium tetraphenylborate (Scheme).
Table 1. Palladium-Catalyzed Coupling of Norbornadiene and
Diphenyliodonium Tetrafluoroborate (2) with Organostannanes 4,
Alkynes 5, or Sodium Tetraphenylborate (6)a
Entry Substrate
Reaction Time (h) Product Yield (%)b
1
2
3
4
5
PhSnBu3
4a
Ph–C≡C–SnBu3 1.5
4b
PhC≡CH
5
NaBPh4
6
PhB(OH)2
7
2
8a
9
84
88
76
72
38
1
1
2
9
8a
8a
6
7
6, CO
7, CO
1
2
10
10
73
32
a
Reaction conditions: Pd(OAc)2 (5 mol %), DMF, norbornadiene
(2 equiv), diphenyliodonium tetrafluoroborate (1 equiv), substrate
(1 equiv).
Isolated yield.
Scheme
b
The results of the ternary coupling of norbornadiene and This ternary coupling was extended to arenediazonium
diphenyliodonium tetrafluoroborate with organostan- tetrafluoroborates and the results are summarized in Table
nanes, phenylacetylene, sodium tetraphenylborate, and 2. Because of the economic advantage of anilines over
phenylboronic acid catalyzed by palladium acetate are aryl bromides or iodides, the palladium-catalyzed cou-

SYNTHESIS
Short Papers
1250
MS (EI): m/z (%) = 246 (M+, 1), 202 (12), 180 (100), 179 (31), 115
(4).
Table 2. Palladium-Catalyzed Coupling of Norbornadiene and Aryl-
diazonium Tetrafluoroborate 3 with Organostannanes 4, Alkynes 5,
or Sodium Tetraphenylborate (6)a
2-exo-Phenyl-3-exo-(p-nitrophenyl)bicyclo[2.2.1]hept-5-ene (8b):1
To a stirred solution of p-nitrophenyldiazonium tetrafluoroborate (3b;
128 mg, 0.54 mmol) and norbornadiene (1; 100 mg, 1.09 mmol) in
anhyd DMF (2 mL) at r.t. was added Pd(OAc)2 (6.1 mg, 5 mol %)
followed by sodium tetraphenylborate (6; 185 mg, 0.54 mmol) in an-
hyd DMF (2 mL) for 1 h via a syringe pump and then stirred for 1 h
more. The reaction mixture was quenched with sat. KF solution and
extracted with Et2O (3 × 10 mL). The organic layer was dried
(MgSO4) and evaporated in vacuo. The crude product was separated
by silica gel column chromatography (hexanes, Rf 0.36) to afford 8b
(98 mg, 62%).
Entry Diazonium
Salt
Substrate
Reaction Product Yield
Time (h)
(%)b
1
2
3
4
PhN2BF4
3a
3a
PhSnBu3
4a
Ph–C≡C–SnBu3 1.5
4b
NaBPh4
6
2
8a
74
9
72
9
3a
1
2
8a
70
4-NO2C6H4N2BF4 4a
10
65
3b
1H NMR (CDCl3, 400 MHz): δ = 1.78 (m, 1H), 2.33 (d, J = 8.8 Hz,
1H), 3.12 (m, 2H), 3.21 (d, J = 1.8 Hz, 2H), 6.45 (d, J = 1.8 Hz, 2H),
6.90–7.26 (m, 9H).
5
6
3b
6
6
1
1
8b
8a
62
52
4-BrC6H4N2BF4
3c
IR (KBr): ν = 3087, 1634, 1457, 812 cm–1.
a
MS (EI): m/z (%) = 291 (M+, 1), 167 (32), 149 (100), 71 (54).
Reaction conditions: Pd(OAc)2 (5 mol %), DMF, norbornadiene
(2 equiv), aryldiazonium tetrafluoroborate (1 equiv), substrate
(1 equiv).
Isolated yield.
b
2-exo-Phenyl-3-exo-(phenylethynyl)bicyclo[2.2.1]heptene (9):2a
Method A: To a stirred solution of 2 (200 mg, 0.54 mmol) and norbor-
nadiene (1; 100 mg, 1.09 mmol) in anhyd DMF (2 mL) at r.t. was
added Pd(OAc)2 (6.1 mg, 5 mol %) followed by phenylacetylene (5;
55.5 mg, 0.54 mmol) in anhyd DMF (2 mL) for 1 h via a syringe pump
and then stirring was continued for 1 h more. The reaction mixture
was quenched with sat. KF solution and extracted with Et2O (3 ×
10 mL). The organic layer was dried (MgSO4) and evaporated in vac-
uo. The crude product was separated by silica gel column chromatog-
raphy (hexanes, Rf 0.34) to afford 9 (112 mg, 76%).
pling of arenediazonium salts received much attention.
The norbornadiene (1) was reacted with phenyldiazonium
tetrafluoroborate (3a) in the presence of tributylphenyltin
(4a) and Pd(OAc)2 (5 mol %) as a catalyst to afford the
coupled product 8a in 74% yield (entry 1 in Table 2). By
the same method, alkynylorganostannane 4b was also
coupled to give the compound 9 (entry 2). The ternary
coupling with NaBPh4 (6) was also carried out to give the
compound 8a (entry 3). The phenyl-substituted diazoni-
um salts were also utilized in this coupling. The p-nitro-
phenyldiazonium tetrafluoroborate (3b) and norborna-
diene (1) were treated with PhSnBu3 (4a) and NaBPh4 (6)
to provide 10 and 8b, respectively (entries 4 and 5). Final-
ly, it is noteworthy to note that p-bromophenyldiazonium
tetrafluoroborate (3c) was coupled with norbornadiene (1)
and NaBPh4 to afford 8a in 52% yield (entry 6).
1H NMR (CDCl3, 400 MHz): δ = 1.68 (m, 1H), 2.18 (m, 1H), 2.94 (m,
1H), 3.03 (m, 1H), 3.15 (m, 2H), 6.24 (d, J = 3.6 Hz, 1H), 6.39 (d, J
= 3.6 Hz, 1 H), 6.85 (m, 2H), 7.12–7.31 (m, 8 H).
IR (KBr): ν = 3112, 1628, 1469, 780 cm–1.
MS (EI): m/z (%) = 246 (M+, 1), 202 (12), 180 (100), 179 (31), 115
(4).
Method B: To a stirred solution of phenydiazonium tetrafluoroborate
(3a; 104 mg, 0.54 mmol) and norbornadiene (1; 100 mg, 1.09 mmol)
in anhyd DMF (2 mL) at r.t. was added Pd(OAc)2 (6.1 mg, 5 mol%)
followed by 4b (189 mg, 0.54 mmol) in anhyd DMF (2 mL) for 1 h
via a syringe pump and the stirring was continued for 1 h more. The
reaction mixture was quenched with sat. KF solution and extracted
with Et2O (3 × 10 mL). The organic layer was dried (MgSO4) and
evaporated in vacuo. The crude product was separated by silica gel
column chromatography (hexanes, Rf 0.34) to afford 9 (106 mg,
72%).
However, in our hands the reaction of norbornadiene and
aryldiazonium salts with alkynes and boronic acids gave
low yields in this ternary coupling.
Three-Component Coupling Reaction: Palladium-Catalyzed Cou-
pling of Norbornadiene and Iodonium Salts or Diazonium Salts with
Organostannanes, Alkynes, and Sodium Tetraphenylborate; Typical
procedures:
2-exo-3-exo-Bis[(phenyl)methanoyl]bicyclo[2.2.1]heptene (10):7
To a stirred solution of 2 (200 mg, 0.54 mmol) and norbornadiene (1;
100 mg, 1.09 mmol) under carbon monoxide (1 atm) in anhyd DMF
(2 mL) at r.t. was added Pd(OAc)2 (6.1 mg, 5 mol %) followed by
NaBPh4 (6; 186 mg, 0.54 mmol) in anhyd DMF (2 mL) for 1 h via a
syringe pump and the stirring was continued for 1 h more. To the
reaction mixture was added Et2O (20 mL) and the Et2O layer was
washed with H2O (3 × 20 mL). The organic layer was dried (MgSO4)
and evaporated in vacuo. The crude product was separated by silica
gel column chromatography (EtOAc/ hexanes, 1:6, Rf 0.38) to afford
10 (119 mg, 73%).
2-exo-3-exo-Diphenylbicyclo[2.2.1]hept-5-ene (8a):1
To a stirred solution of diphenyliodonium tetrafluoroborate (2; 200 mg,
0.54 mmol) and norbornadiene (1; 100 mg, 1.09 mmol) in anhyd DMF
(2 mL) at r.t. was added Pd(OAc)2 (6.1 mg, 5 mol %) followed by tribut-
ylphenyltin (4a; 200 mg, 0.54 mmol) in anhyd DMF (2 mL) for 1 h via
a syringe pump and the stirring was continued for 1 h more. The reac-
tion mixture was quenched with sat. KF solution and extracted with
Et2O (3 × 10 mL). The organic layer was dried (MgSO4) and evaporat-
ed in vacuo. The crude product was separated by silica gel column
chromatography (hexanes, Rf 0.35) to afford 8a (112 mg, 84%).
1H NMR (CDCl3, 400 MHz): δ = 1.78 (m, 1H), 2.32 (d, J = 8.8 Hz,
1H), 3.11 (m, 2H), 3.21 (d, J = 1.8 Hz, 2H), 6.44 (d, J = 1.8 Hz, 2H),
6.89–7.26 (m, 10H).
1H NMR (CDCl3, 400 MHz): δ = 1.51 (m, 1H), 2.08 (d, J = 9.0 Hz,
1H), 3.27 (m, 2H), 3.65 (d, J = 1.5 Hz, 2H), 6.43 (s, 2H), 7.29–7.47
(m, 6H), 7.75 (m, 4H).
IR (KBr): ν = 3088, 1699, 1600, 1468, 770 cm–1.
MS (EI): m/z (%) = 302 (M+, 2), 237 (11), 197 (15), 180 (12), 105
(100).
IR (KBr): ν = 3112, 1628, 1469, 780 cm–1.

SYNTHESIS
September 1998
1251
Generous financial supports from KOSEF-OCRC, KOSEF(97-0501-
02-01-3) and Ministry of Education (BSRI-97-3420) are gratefully
acknowledged.
(4) Kang, S-K.; Jung K-Y.; Park, C-H.; Jang, S-B. Tetrahedron Lett.
1995, 36, 8047.
Kang, S-K.; Lee, H-W.; Jang, S-B.; Kim, T-H.; Pyun, S.-J. J. Org.
Chem. 1996, 61, 2604.
Kang, S-K.; Lee, H-W.; Jang, S-B.; Ho, P-S. J. Chem. Soc.,
Chem. Commun. 1996, 835.
Kang, S-K.; Lee, H-W.; Kim, J-S.; Choi, S-C. Tetrahedron Lett.
1996, 37, 3723.
Kang, S-K.; Lee, H-W.; Jang, S-B.; Ho, P-S. J. Org. Chem. 1996,
61, 4720.
Kang, S-K.; Yamaguchi, T.; Hong, R-K.; Kim, T-H.; Pyun, S-J.
Tetrahedron 1997, 53, 3027.
Kang, S-K.; Lim, K-H.; Ho, P-S.; Kim, W-Y. Synthesis 1997,
874.
Kang, S-K.; Yamaguchi, T.; Ho, P-S.; Kim, W-Y.; Yoon, S-K.
Tetrahedron Lett. 1997, 38, 1947.
Kang, S-K.; Yamaguchi, T.; Kim, T-H.; Ho, P-S. J. Org. Chem.
1996, 61, 9082.
(1) Catellani, M.; Chiusoli, G. P. Tetrahedron Lett. 1982, 23, 4517.
Larock, R. C.; Babu, S. Tetrahedron 1987, 43, 2013.
Kosugi, M.; Tamura, H.; Sano, H.; Migita, T. Tetrahedron 1989,
45, 961.
Catellani, M.; Chiusoli, G. P.; Concari, S. Tetrahedron 1989, 45,
5263.
Larock, R. C.; Hershberger, S. S.; Takagi, K.; Mitchell, M. A.
J. Org. Chem. 1986, 51, 2450.
Torii, S.; Okumoto, H.; Ozaki, H.; Nakayasu, S.; Kotani, T.
Tetrahedron Lett. 1990, 31, 5319.
Torii, S.; Okumoto, H.; Ozaki, H.; Nakayasu, S.; Tadokoro, T.;
Kotani, T. Tetrahedron Lett. 1992, 33, 3499.
Torii, S.; Okumoto, H.; Kotani, T.; Nakayasu, S.; Ozaki, H.
Tetrahedron Lett. 1992, 33, 3503.
(5) Stang, P. J.; Zhdankin, V. V. Chem. Rev. 1996, 96, 1123.
(6) The palladium-catalyzed coupling of arenediazonium salts: Dar-
ses, S.; Jeffery, T.; Genet, J-P.; Brayer, J-L.; Demoute, J-P. Tetra-
hedron Lett. 1996, 37, 3857, and references cited therein.
Kikukawa, K.; Idemoto, T.; Katayama, A.; Kono, K.; Wada, F.;
Matsuda, T. J. Chem. Soc., Perkin Trans. I 1987, 1511, and ref-
erences cited therein.
Ozawa, F.; Kobatake, Y.; Kubo, A.; Hayashi, T. J. Chem. Soc.,
Chem. Commun. 1994, 1323.
Moinet, C.; Fiaud, J-C. Tetrahedron Lett. 1995, 36, 2051.
(2) Kosugi, M.; Kimura, T.; Oda, H.; Migita, T. Bull. Chem. Soc. Jpn.
1993, 66, 3522.
Oda, H.; Ito, K.; Kosugi, M.; Migita, T. Chem. Lett. 1994, 1443.
(3) Oda, H.; Hamataka, K.; Fugami, K.; Kosugi, M.; Migita, T.
Synlett 1995, 1225.
(7) Freeman, F.; Kim, J. D.; Lee, M. Y.; Wang, X. Tetrahedron 1996,
52, 5699, and references cited therein.