A novel tandem arylsulfonylation and cyclization of arylazoxy aryl sulfones with norbornene catalyzed by a palladium(O) complex

Article abstract of DOI:10.1016/0022-328X(91)86218-F

The reaction of arylazoxy aryl sulfones with norbornene in the presence of tetrakis(triphenylphosphine)palladium(O) was found to give cis, exo-2,3-norbornane-fused 2,3-dihydrobenzotiophene 1,1-dioxides in good yield.

Full text of DOI:10.1016/0022-328X(91)86218-F

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Journal of Organometallic Chemistry, 401 (1991) C26-C29
Elsevier SequoiaS.A., Lausanne
JOM 21465PC
Preliminary communication
A novel tandem arylsulfonylation and cyclization
of arylazoxy aryl sulfones with norbornene catalyzed
by a palladium(0) complex
Nobumasa Kamigata *, Mayumi Satoh and Masato Yoshida
Department of Chemistry, Faculty of Science, Tokyo Metropolitan University, Fukazawa, Setagaya-ku,
Tokyo 158 (Japan)
(Received June 21st, 1990)
A
~ t
The reaction of arylazoxy aryl sulfones with norbornene in the presence of tetrakis(triphenylphos-
phine)palladium(0) was found to give cis, exo-2,3-norbornane-fused 2,3-dihydrobenzo[b]thiophene 1,1-di-
oxides in good yield.
Recently, much attention has been paid to palladium catalyzed reactions in
organic syntheses [1]. Arylation of alkenes with aryl halides or aryl mercurious
compounds catalyzed by a palladium complex is the well known Heck reaction [2].
We previously reported a novel arylation of olefins [3] or a,fl-unsaturated esters and
nitriles [4] with arylazoxy aryl sulfones (1) catalyzed by a palladium(0) complex; a
reaction mechanism via a diarylpalladium(II) species was proposed. In the course of
our systematic studies on this reaction, we found a hitherto unknown tandem
arylsulfonylation and cyclization of 1 with norbornene.
The reaction of phenylazoxy phenyl sulfone (la) with norbornene proceeds
smoothly in the presence of a catalytic amount of tetrakis(triphenylphosphine)pal-
ladium(0) in benzene to give cis, exo-2,3-norbornane-fused 2,3-dihydrobenzo[b]thio-
phene 1,1-dioxide (2a) and biphenyl (3a) in 65 and 43% yield, respectively. Similarly,
the reactions of arylazoxy aryl sulfone (1b-e) with norbornene catalyzed by a
palladium(0) complex were also carried out to give the corresponding cis, exo-
norbornane-fused dihydrobenzothiophenes (2) and biaryls (3) in good yields. The
results are summarized in Table 1.
The catalytic cycle of this novel reaction of 1 with norbornene is accounted for
by Scheme 1. Oxidative addition of 1 to the palladium(0) catalyst forms adduct 4,
which selectively eliminates dinitrogen monoxide to give the aryl(arylsulfonyl)pal-
ladium(II) intermediate (5). Syn-addition of 5 to the carbon-carbon double bond of
norbornene from the exo-side gives adduct 6. Subsequently ortho-palladafion occurs
on the arylsulfonyl group to give the palladium(IV) complex 7. The reductive
elimination of 2 from 7 gives arylhydridopalladium(II) (8). The characteristic
0022-328X/91/$03.50
© 1991 - ElsevierSequoia S.A.

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o
Pd(PPha)4
X ~ - ~ = N - S ~ - ~ y
+
C6H6, 80 °C B
X O C 6 H 5
3
2
Table 1
Reactions of azoxysulfones 1 with norbornene catalyzed by a palladium(O) complex
X and Y in 1
X
Products, Yield (%)
Y
la
lb
ic
ld
le
H
H
CH 3
CH3
CI
H
CH3
H
CH3
CI
2a
2b
2a
2b
2c
65
70
62
80
61
3a
3a
3b
3b
3c
43
45
40
43
45
0
~ArI-I~=N-~-Ar 2
o'-
°
C6H6 " ~
Ar1-1~=N-ed(ll)-~-Ar2
ArLPd(II)-H
8
O-
4
>N20
O
II
Ar~ /H
Ar"Pd(ll) -S-Ar2
5
2
Y
O*"O
7
~
,.,.~fPd(ll)Ar'
/ . ~ $ O 2 A r2
6
Scheme I

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differences found in the palladium(0)-catalyzed reaction of 1 and norbornene
compared with the reported reaction of 1 with acyclic and cyclic olefins [3] or
unsaturated esters and nitriles [4] may be accounted for as follows: (a) norbornene
is much more reactive than ordinary acyclic or cyclic olefins, and hence 5 adds to
norbornene before it eliminates sulfur dioxide; (b) ortho-palladation on the
arylsulfonyl group occurs in this case since there is no fl-hydrogen at the syn-posi-
tion to eliminate the arylpaUadium(II) moiety in adduct 6. Syn-addition and
syn-elimination of an arylpalladium(II) moiety (ArlPd) containing /J-hydrogen is
reported by Kikukawa et al. in the case of ordinary olefins [5].
The sole biphenyl derivative formed was Ar1C6H5 (3) and no Ar2C6H~ was
detected in the reaction mixtures. These findings suggest that the arylhydridopal-
ladium(II) species (8), once formed, reacts with the solvent benzene to give biphenyl
derivatives as shown in Scheme 1; however, no formation of hydrogen could be
confirmed. The yield of biphenyl derivative 3 was lower than that of 2 in all the
reactions. This may be accounted for by the reductive elimination occurring
competitively from arylhydridopalladium(II) (8) to give arene and palladium(0):
Ar'-Pd(II)-H
-~ Ar'H + Pd(0)
Recently, Catellani and Chiusoli have reported an interesting reaction of
bromobenzene with norbornene catalyzed by a palladium(0) complex in the pres-
ence of potassium butoxide to give double arylation and cyclization products,
hexahydromethanotriphenylenes [6]. However, the present palladium(0)-catalyzed
tandem arylsulfonylation/cyclization is a hitherto unknown reaction. Further stud-
ies on the scope and limitations of the novel reaction are in progress.
General procedure
A solution containing arylazoxy aryl sulfone (1) (1.0 mmol), norbornene (1.0
mmol), and tetrakis(triphenylphosphine)palladium(0) (0.01 mmol) in dry benzene (5
ml) was degassed by a freeze-thaw cycle, sealed in an ampoule, and kept at 80 °C
for 24 h. The reaction mixture was subjected to short column chromatography on
Florisil using benzene as eluent to remove the metal complex. The products were
isolated from the reaction mixture by column chromatography on Florisil using
hexane:ethyl acetate:chloroform (50:25:1) as the eluent and/or by gel-permea-
tion chromatography, and their structures were determined by IR, NMR, and mass
spectrometry. The structures of biphenyl, p-methylbiphenyl, and p-chlorobiphenyl
were identified by comparison of their IR, 1H NMR, and mass spectral data with
those of authentic samples.
cis,exo-2,3-Norbornane-fused 2,3-dihydrobenzo[b]thiophene 1,1-dioxide (2a):
m.p. 137-138°C; IR (neat) 1310 and 1145 c m - l ; 1H NMR (CDC13) 8 1.10 (1H, d,
J 11.0 Hz), 1.22 (1H, d, J 11.0 Hz), 1.26-1.78 (4H, m), 2.47 (1H, br s), 2.93 (1H, br
13
s), 3.27 and 3.54 (2H, ABq, J 8.0 Hz), and 7.36-7.70 (4H, m); C NMR (CDC13) 8
27.4, 28.1, 33.6, 39.1, 43.0, 50.1, 66.1, 121.2, 126.7, 128.3, 128.8, 133.5, and 139.3;
MS m/z 234 (M+), 216, 199, 167, 142, 137, and 129; HRMS found 234.0676;
C13H14025 calc.: M 234.0714.
cis, exo-2,3-Norbornane-fused 5-methyl-2,3-dihydrobenzo[b]thiophene 1,1-dioxide
(2b): m.p. 116-117°C; IR (neat) 1320 and 1150 c m - l ; 1H NMR (CDC13) 8 1.12
(1H, d, J 11.1 Hz), 1.18 (1H, d, J 11.1 Hz), 1.27-1.73 (4H, m), 2.39 (3H, s), 2.46

c29
(1H, br s), 2.92 (1H, br s), 3.23 and 3.47 (2H, ABq, J 7.8 Hz), 7.16 (1H, s), and 7.21
and 7.54 (2H, ABq, J 8.0 Hz); ~3C NMR (CDCI3) ~ 21.7, 27.4, 28.1, 33.6, 39.1,
43.0, 49.9, 66.5, 120.9, 126.9, 129.9, 138.5, 139.7, and 144.5; MS m/z 248 ( M + ) , 231,
213, 201, 181, 156, 151, and 143; HRMS found 248.0914; Clan1602S calc.:
M
248.0871.
cis,exo-2,3-Norbornane-fused 5-chloro-2,3-dihydrobenzo[b]thiophene 1,1-dioxide
(2e): m.p. 131-132°C; IR (neat) 1320 and 1160 cm-~; 1H NMR (CDC13) 8 1.11
(1H, d, J 11.0 Hz), 1.20 (1H, d, J 11.0 Hz), 1.28-1.76 (4H, m), 2.48 (1H, br s), 2.94
(1H, br s) 3.28 and 3.50 (2H, ABq, J 7.7 Hz), 7.35 and 7.60 (2H, ABq, J 9.2 Hz),
and 7.37 (1H, s): 13C NMR (CDC13) ~ 27.3, 28.1, 33.8, 39.2, 43.0, 49.7, 66.6, 122.5,
126.9, 129.5, 139.7, 140.0, and 141.4; MS m/z 268 ( M + ) , 234, 216, and 199; HRMS
found 268.0356, C13H1302SC1 calc.: M 268.0324.
References
1 J. Tsuji, Organic Synthesis with PalladiumCompounds, Springer-Vedag, New York, 1980; R.F. Heck,
Palladium Reagents in Organic Syntheses, Academic Press, New York, 1985.
2 R.F. Hock, Pure Appl. Chem., 50 (1978) 691; R.F. Heck, Acc. Chem. Res., 12 (1979) 146.
3 N. Kamigata, T. Fukushima, A. Satoh and M. Kameyama, Sulfur Lett., 7 (1988) 181; N. Kamigata, T.
Fukushima, A. Satoh and M. Kameyama, J. Chem. Soc., PerkinTrans. 1, (1990) 549.
4 N. Kamigata, M. Satoh and T. Fukushima, Bull. Chem. Soc. Jpn., 63 (1990) 2118.
5 K. Ikenaga, K. Kikukawa and T. Matsuda, J. Org. Chem., 52 (1987) 1276; K. Kikukawa, K. Ikenaga,
F. Wada and T. Matsuda, Chem. Lett., (1983) 1337.
6 M. Catellani and G.P. Chiusoli, J. Organomet. Chem., 286 (1985) C13.