6316
S. Kodama et al. / Tetrahedron Letters 48 (2007) 6312–6317
PdL4 (L = PPh3)
-2L
PdL2
References and notes
O
2L
1. For reviews concerning transition-metal-catalyzed addi-
tion reactions of group 16 heteroatom compounds to
carbon–carbon unsaturated bonds, see: (a) Ogawa, A. In
Main Group Metals in Organic Synthesis; Yamamoto, H.,
Oshima, K., Eds.; Wiley-VCH: Weinheim, 2004; Vol. 2,
Chapter 15; (b) Beletskaya, I.; Moberg, C. Chem. Rev.
2006, 106, 2320–2354; (c) Alonso, F.; Beletskaya, I. P.;
Yus, M. Chem. Rev. 2004, 104, 3079–3159; (d) Ogawa, A.
In Handbook of Organopalladium Chemistry for Organic
Synthesis; Negishi, E., Ed.; Wiley-Interscience: New York,
2002, Chapter VII.6; (e) El Ali, B.; Alper, H. In Handbook
of Organopalladium Chemistry for Organic Synthesis;
Negishi, E., Ed.; Wiley-Interscience: New York, 2002,
Chapter VI.2.1.1.2; (f) Kuniyasu, H. In Catalytic Hetero-
R
SPh
SPh
(PhS)2
O
L2Pd(SPh)2
R
Pd(SPh)L2
SPh
A
G
functionalization; Togni, A., Grutzmacher, H., Eds.;
¨
R
Wiley-VCH: Weinheim, 2001, Chapter 7; (g) Kondo, T.;
Mitsudo, T. Chem. Rev. 2000, 100, 3205–3220; (h) Ogawa,
A. J. Organomet. Chem. 2000, 611, 463–474; (i) Belets-
kaya, I.; Moberg, C. Chem. Rev. 1999, 99, 3435–3461; (j)
Han, L.-B.; Tanaka, M. Chem. Commun. 1999, 395–402.
2. (a) Ogawa, A.; Kawakami, J.-i.; Sonoda, N.; Hirao, T. J.
Org. Chem. 1996, 61, 4161–4163; (b) Ogawa, A.; Kudo,
A.; Hirao, T. Tetrahedron Lett. 1998, 39, 5213–5216; (c)
Xiao, W.-J.; Vasapollo, G.; Alper, H. J. Org. Chem. 1998,
63, 2609–2612; (d) Xiao, W.-J.; Alper, H. J. Org. Chem.
1999, 64, 9646–9652; (e) Kondo, T.; Uenoyama, S.; Fujita,
K.; Mitsudo, T. J. Am. Chem. Soc. 1999, 121, 482–483; (f)
Arisawa, M.; Suwa, A.; Fujimoto, K.; Yamaguchi, M.
Adv. Synth. Catal. 2003, 345, 560–563; (g) Kamiya, I.;
Nishinaka, E.; Ogawa, A. Tetrahedron Lett. 2005, 46,
3649–3652.
3. Transition-metal-catalyzed heterofunctionalization of
allenes was reported. For reviews, see: (a) Yamamoto,
Y.; Radhakrishnan, U. Chem. Soc. Rev. 1999, 28, 199–
207; (b) Zimmer, R.; Dinesh, C. U.; Nandanan, E.; Khan,
F. A. Chem. Rev. 2000, 100, 3067–3125; (c) Mandai, T. In
Modern Allene Chemistry; Krause, N., Hashmi, A. S. K.,
Eds.; Wiley-VCH: Weinheim, 2004; Vol. 2, pp 925–972.
4. Ogawa, A.; Yokoyama, K.; Yokoyama, H.; Sekiguchi,
M.; Kambe, N.; Sonoda, N. Tetrahedron Lett. 1990, 31,
5931–5934.
CO
•
Pd(SPh)L2
SPh
R
B
Scheme 2. A possible pathway for carbonylative bisthiolation of
allenes with (PhS)2.
Scheme 2 shows a possible reaction pathway for this car-
bonylative bisthiolation, which includes the following:
(i) After oxidative addition of (PhS)2 to Pd(PPh3)2, thio-
palladation of allene takes place at the terminal carbon–
carbon double bond to form vinylpalladium intermedi-
ate B; (ii) carbon monoxide inserts into the Pd–C bond
to form acylpalladium intermediate G; (iii) reductive
elimination takes place to form the carbonylative bisthi-
olation product with regeneration of the catalyst. In this
carbonylation, the product H derived from the carbon-
ylation at the terminal carbon of allenes was not
obtained at all. This result suggests that the thiopal-
ladation of allenes takes place at the terminal carbon–
carbon double bonds to form vinylpalladium intermedi-
ate B.
5. A stoichimetric reaction of a disulfide complex (Mo–Mn)
with allenes has been reported, see: Adams, R. D.;
Captain, B.; Kwon, O. S.; Miao, S. Inorg. Chem. 2003,
42, 3356–3365.
6. In addition, we conducted the Pd(PPh3)4-catalyzed addi-
tion of (PhS)2 to 1a in the presence of galvinoxyl to the
reaction mixture. As a result, the bisthiolation of 1a
proceeded successfully.
R
SPh
SPh
O
H
In summary, we have developed highly regioselective
bisthiolation of allenes with diphenyl disulfide catalyzed
by palladium(0) complex. Since radical addition of the
disulfide to allenes affords a complex mixture, the present
transition-metal-catalyzed reaction is useful for provid-
ing bisthiolated adducts. In addition, the carbonylative
bisthiolation and bisselenation are investigated in detail.
We believe that these reactions expand the utility of the
transition-metal-catalyzed reactions of group 16 hetero-
atom compounds.
7. General procedure for the Pd(PPh3)4-catalyzed bisthiola-
tion of allenes: To a mixture of allene (0.5–1.8 mmol) and
Pd(PPh3)4 (5 mol %) in solvent (0.5–1.5 mL) was added
diphenyl disulide (0.5–1.5 mmol) under N2 atmosphere.
The resulting mixture was stirred magnetically for 12 h
with heating at refluxing temperature (e.g., CH3CN;
82 °C). After the reaction was complete, the reaction
mixture was filtered through Celite, followed by washing
with diethyl ether. The combined filtrate was concentrated
under the reduced pressure. The products (2) were
1
confirmed by H NMR spectroscopy. The purification of
Acknowledgments
the products was performed by preparative TLC on silica
gel using hexane/AcOEt = 100:0–96:4 as an eluent.
This work is supported by Grant-in-Aid for Scientific
Research on Priority Areas (Area 444, No. 19020061)
and Scientific Research (B, 19350095), from the Minis-
try of Education, Culture, Sports, Science and Technol-
ogy, Japan.
8. The spectral and analytical data for the bisthiolation
product, for example, 2a is as follows: a yellow oil
(obtained as
a
stereoisomeric mixture); 1H NMR
(400 MHz, CDCl3) [E-isomer]: d 1.02–1.13 (m, 5H),
1.14–1.42 (m, 3H), 1.50–1.62 (m, 2H), 1.98–2.10 (m,