Substitution of acetylenic groups for halogen in the quinonoid ring

Article abstract of DOI:10.1007/s11172-006-0023-7

The bromine or iodine atom in the quinonoid ring devoid of+M substituent in the position neighboring to the halogen is replaced by acetylenic groups on treatment with Cu^I acetylides, prepared either beforehand or in situ, in a mixture of DMSO a

Full text of DOI:10.1007/s11172-006-0023-7

1686
Russian Chemical Bulletin, International Edition, Vol. 54, No. 7, pp. 1686—1689, July, 2005
Substitution of acetylenic groups for halogen in the quinonoid ring
V. S. Romanov,a I. D. Ivanchikova,a A. A. Moroz,b and M. S. Shvartsberga
ꢀ
aInstitute of Chemical Kinetics and Combustion, Siberian Branch of the Russian Academy of Sciences,
3 ul. Institutskaya, 630090 Novosibirsk, Russian Federation.
Fax: +7 (383) 330 7350. Eꢀmail: shvarts@ns.kinetics.nsc.ru
bKemerovo State University,
6 ul. Krasnaya, 650099 Kemerovo, Russian Federation.
The bromine or iodine atom in the quinonoid ring devoid of +M substituent in the position
neighboring to the halogen is replaced by acetylenic groups on treatment with CuI acetylides,
prepared either beforehand or in situ, in a mixture of DMSO and CHCl3 in the presence of a Pd
complex catalyst. A series of monoꢀ and diacetylenic derivatives of 1,4ꢀnaphthoꢀ and
1,4ꢀbenzoquinone were prepared.
Key words: 2ꢀbromoꢀ and 2,3ꢀdibromonaphthoquinones, 2,5ꢀdiiodoꢀ1,4ꢀbenzoquinone,
CuI acetylides, crossꢀcoupling, alkynylquinones.
Quinones containing acetylenic substituents in the
It was found that 2ꢀbromoꢀ (1) and 2,3ꢀdibromoꢀ1,4ꢀ
naphthoquinone (2) react with cuprous acetylides 3 in a
(1—2) : 1 DMSO—CHCl3 mixture in the presence of
Pd(PPh3)2Cl2 at 35—50 °C to give the corresponding
2ꢀacetylenylꢀ (4) and 2,3ꢀdiacetylenylꢀ1,4ꢀnaphthoꢀ
quinones (5) in satisfactory yields (40—70%) (Scheme 1).
The reaction time is 15—130 min. The reaction can be
carried out not only with solid cuprous acetylides preꢀ
pared beforehand but also with those obtained in situ from
quinonoid ring are promising key intermediates in the
preparation of heterocyclic quinones1—3 and highly reacꢀ
tive unsaturated compounds.4,5 There are two approaches
to the synthesis of these acetylenylquinones: oxidation of
acetylenic derivatives of some aromatic compounds to
quinones6,7 and the introduction of acetylenic substituꢀ
ents directly into the quinoid ring.8 The implementation
of the former is often complicated by the large number of
stages, low accessibility of aromatic precursors, and inꢀ
sufficient selectivity of oxidants. The direct introduction
of acetylenic substituents into the quinonoid ring is posꢀ
sible either through the addition of alkali metal acetylide
to the carbonyl groups of dialkoxybenzoquinone followed
by acidic hydrolysis and dehydration,9 or through cataꢀ
lyzed substitution of halogen atoms on treatment with
terminal acetylenes or metal acetylides.8 The application
of the alkynol route is limited exclusively by benzoquinone
derivatives. The condensation of haloquinones, which
seems a priori to be the most facile and efficient method,
is hampered by the enhanced sensitivity of the quinonoid
ring to the bases and nucleophiles used most often in
these reactions.
Scheme 1
Previously,8 we found that haloquinones having a
dialkylamino group or another substituent possessing a
pronounced +Mꢀeffect in the position adjoining the haloꢀ
gen atom in the quinoid ring are less labile in the nucleoꢀ
philic media and react with terminal acetylenes under
usual Pdꢀ and Cuꢀcatalyzed crossꢀcoupling conditions.
In the present study we demonstrate the possibility and
elucidate plausible conditions for the substitution of acetyꢀ
lenic groups for the halogen atoms in the quinonoid ring
not deactivated by the neighboring +M substituent.
R = Ph (a), 4ꢀO2NC6H4 (b), 4ꢀMeOC6H4 (c), C(OH)Me2 (d),
C(OMe)Me2 (e)
Reagents: i. CuC≡CR (3a—c), Pd(PPh3)2Cl2 or
HC≡CR (6d), CuI, NEt3, Pd(PPh3)2Cl2; ii. HC≡CR (6a,d,e),
CuI, NEt3, Pd(PPh3)2Cl2.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1636—1639, July, 2005.
1066ꢀ5285/05/5407ꢀ1686 © 2005 Springer Science+Business Media, Inc.

Substitution of halogen in quinones
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 7, July, 2005
1687
Scheme 3
terminal acetylenes 6, CuI, and Et3N. This allows one to
use acetylenic compounds forming no acetylides stable in
the solid state, for example, tertiary αꢀacetylenic alcohols.
This extends the scope of applicability of this reaction.
It should be emphasized that the palladium catalyst
should be used in any case; without the catalyst, the conꢀ
densation does not take place (it has been demonstrated
previously10 that in the presence of palladium complexes,
the temperature of cuprous phenylacetylide condensation
with aryl halides can be markedly decreased). The choice
of DMSO is due to the fact that bromides 1 and 2 are
relatively stable in this solvent, as opposed to solvents
traditional for crossꢀcoupling (pyridine, DMF, Et3N, and
so on). However, the condensation of these compounds
with cuprous acetylides 3 in DMSO is accompanied by
significant resinification, which can be appreciably reꢀ
duced by adding a second solvent component, CHCl3.
Under these conditions, not only halo derivatives of
polycyclic 1,4ꢀquinones, such as bromonaphthoquinones
1 and 2, but also halobenzoquinones, for example, 2,5ꢀdiꢀ
iodoꢀ1,4ꢀbenzoquinone (7) are condensed with cuprous
acetylides (Scheme 2).
R = Ph (12a, 13, 14), C(OH)Me2 (12d);
Z = NHAc (9, 12a,d), N(Ac)Ph (10, 13), OEt (11, 14)
of solid acetylide 3а prepared beforehand was required;
the condensation lasted for 6 h at 37 °C and was accomꢀ
panied by substantial resinification. In the series of 2ꢀsubꢀ
stituted 3ꢀbromoꢀ1,4ꢀnaphthoquinones, the ethoxy group,
which exerts a pronounced +Mꢀeffect, is apparently reꢀ
sponsible for the limit of applicability of the method. As
has been shown previously,8 3ꢀbromoꢀ2ꢀethoxyꢀ1,4ꢀ
naphthoquinone 11 reacts satisfactorily with terminal
acetylenes under conditions used for condensation of staꢀ
bilized 2ꢀdialkylaminoꢀ3ꢀbromoꢀ1,4ꢀnaphthoquinones.
However, the same bromide 11 retains the ability to be
coupled with acetylides under specific conditions of conꢀ
densation of reactive nonstabilized haloquinones.
It is noteworthy that the proposed crossꢀcoupling proꢀ
cedure seems to be the only existing method for the reꢀ
placement of a nondeactivated halogen atom in the
quinoid ring.11
Scheme 2
The condensation of diiodide 7 with cuprous phenylꢀ
acetylide 3а takes place even at 20 °C with selfꢀheating
and ends after 20 min; the yield of 2,5ꢀdi(phenylethynyl)ꢀ
1,4ꢀbenzoquinone (8) reaches 84%.
Experimental
The functional groups exhibiting no or weak +Mꢀeffect
deactivate the neighboring position of the quinonoid ring
with respect to a nucleophilic attack to a lesser extent
than strong Mꢀdonors. Therefore, on the replacement of
strong electronꢀdonating groups (NR2, NHR, NH2, OH)
by weaker ones (NHAc, NRAc, etc.), vicꢀfunctionally
substituted haloquinones become able to undergo crossꢀ
coupling under the given conditions. Indeed, 2ꢀsubstiꢀ
tuted 3ꢀbromoꢀ1,4ꢀnaphthoquinones (9—11) condense
with acetylides in DMSO—CHCl3 similarly to bromide 1
to give the corresponding 2ꢀsubstituted 3ꢀacetylenylꢀ1,4ꢀ
naphthoquinones (12a,d, 13, 14) (Scheme 3).
Acetylides were prepared in situ from terminal acetyꢀ
lenes (6a,d). The reactions of bromides 9 and 10 were
carried out at 20—35 °C for 45—180 min. The greatest
difficulties were encountered in the condensation of
ethoxybromonaphthoquinone 11 with acetylide 3a. For
completion of the reaction, the addition of a large excess
1
H NMR spectra were recorded on a Bruker DPXꢀ200 inꢀ
strument (200 MHz) in CDCl3 at 25 °C. The course of the
reactions was monitored and the compound purity was checked
by TLC on Silufol UV 254 plates.
2ꢀPhenylethynylꢀ1,4ꢀnaphthoquinone (4a). А. Triethylamine
(3.30 g, 32.7 mmol, 4.5 mL), phenylacetylene 6а (4.20 g,
41.2 mmol, 4.5 mL), Pd(PPh3)2Cl2 (75 mg), and bromide 1
(7.10 g, 30.0 mmol) were added successively with stirring under
Ar to CuI (17.20 g, 90.1 mmol) in DMSO (100 mL) and CHCl3
(70 mL). The mixture was heated for 50 min at 35—36 °C until
the initial 1 disappeared and poured into 300 mL of CHCl3, the
resulting mixture was filtered, and the filtrate was washed many
times with water and dried with CаCl2. After removal of the
solvent, the residue was triturated with ether (20 mL), and the
precipitate was filtered off and dissolved in CHCl3 (30 mL).
Ethanol (25 mL) was added to the solution, and CHCl3 was
evaporated in vacuo to give 4.30 g (56%) of phenylethynylꢀ
naphthoquinone 4а, m.p. 147—148 °C (from CCl4).6

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Russ.Chem.Bull., Int.Ed., Vol. 54, No. 7, July, 2005
Romanov et al.
B. A mixture of bromonaphthoquinone 1 (2.20 g, 9.3 mmol),
cuprous phenylacetylide 3а (1.60 g, 9.7 mmol), and
Pd(PPh3)2Cl2 (20 mg) in DMSO (20 mL) and CHCl3 (10 mL)
was stirred under argon for 75 min at 35—37 °C. Acetylene 4а
was isolated as described above; yield 1.30 g (54%).
2ꢀ(4ꢀNitrophenylethynyl)ꢀ1,4ꢀnaphthoquinone (4b). Bromoꢀ
naphthoquinone 1 (0.60 g, 2.5 mmol) was condensed with
acetylide 3b (0.70 g, 3.3 mmol) in the presence of Pd(PPh3)2Cl2
(10 mg) in a mixture of DMSO (10 mL) and CHCl3 (5 mL) for
15 min at 35—37 °C. (Nitrophenylethynyl)naphthoquinone 4b
was isolated similarly to acetylene 4а; the yield was 0.53 g (69%)
(Table 1).
2ꢀ(4ꢀMethoxyphenylethynyl)ꢀ1,4ꢀnaphthoquinone (4c). Cuꢀ
prous 4ꢀmethoxyphenylacetylide prepared from acetylene 6c
(0.80 g, 6.1 mmol), CuI (1.50 g, 12.4 mmol), and Et3N (0.55 g,
5.4 mmol, 0.74 mL) in a mixture of DMSO (15 mL) and CHCl3
(8 mL) were condensed with bromonaphthoquinone 1 (1.20 g,
5.1 mmol) in the presence of Pd(PPh3)2Cl2 (12 mg) for 70 min
at 40—41 °C as described in the synthesis of acetylene 4а
(method А). The yield of quinone 4с was 0.75 g (51%) (see
Table 1).
2ꢀ(3ꢀHydroxyꢀ3ꢀmethylbutynyl)ꢀ1,4ꢀnaphthoquinone (4d).
The reaction of bromide 1 (2.40 g, 10.1 mmol), 2ꢀmethylbutꢀ
3ꢀynꢀ2ꢀol (6d) (1.30 g, 15.5 mmol, 1.5 mL), CuI (3.80 g,
19.9 mmol), Et3N (1.10 g, 10.9 mmol, 1.48 mL), and
Pd(PPh3)2Cl2 (40 mg) in a mixture of DMSO (40 mL) and
CHCl3 (30 mL) was carried out as described for the preparation
of acetylenylquinone 4а (method A) at 45—47 °C for 60 min.
The product in ether was filtered through a small SiO2 layer, the
solvent was removed, and the product was recrystallized in dibuꢀ
tyl ether and filtered off. Recrystallization from hexane gave
1.20 g (49%) (see Table 1).
2,3ꢀDi(phenylethynyl)ꢀ1,4ꢀnaphthoquinone (5а). А. The comꢀ
pound was prepared similarly to 2ꢀphenylethynylnaphthoꢀ
Table 1. Acetylenic derivatives of naphthoquinone
Comꢀ M.p./°C
pound (solvent)
Found
Calculated
Molecular
formula
1H NMR (δ, J/Hz)
IR,
ν/cm–1
(%)
N
С
H
4b
4c
4d
203—205
(decomp.,
CHCl3—
ethanol)
153—154
(decomp.,
ether)
70.83 3.07 4.95
71.29 2.99 4.62
C18H9NO4
C19H12O3
C15H12O3
7.24 (s, 1 H, Н(3)); 7.75—7.85 (m, 2 H, Н(6),
Н(7)); 7.77 (d, 2 H, Н(2´), Н(6´), J = 8.5);
8.10—8.25 (m, 2 H, Н(5), Н(8));
1665, 1685
(C=O);
2210 (C=C)
8.26 (d, 2 H, Н(3´), Н(5´), J = 8.5)
78.90 4.22
79.15 4.19
—
—
3.84 (s, 3 H, Me); 6.90 (d, 2 H, Н(3´), Н(5´),
J = 8.5); 7.12 (s, 1 H, Н(3)); 7.56 (d, 2 H,
Н(2´), H(6´), J = 8.5); 7.70—7.90 (m, 2 H,
Н(6), Н(7)); 8.05—8.15 (m, 2 H, Н(5), Н(8))
1.64 (s, 6 H, Me); 3.14 (s, 1 H, ОН); 7.05 (s,
1 H, Н(3)); 7.70—7.75 (m, 2 H, Н(6), Н(7));
8.00—8.05 (m, 2 H, Н(5), H(8))
1660, 1680
(С=О);
2200, 2230
(С≡С)
82—83
(dibutyl
ether)
75.02 4.98
74.99 5.03
1680 (С=О);
2210, 2230
(С≡С);
3520 br (ОН)
5а
5d
>150
87.07 3.95
87.13 3.94
—
—
C26H14O2
C20H18O4
7.30—7.45 (m, 6 H, 4 H Phm, 2 Н Php);
7.60—7.70 (m, 4 H, 4 Н Pho); 7.70—7.80 (m, 2 H, 1695 (С=О);
Н(6), H(7)); 8.10—8.20 (m, 2 H, Н(5), H(8))
1.67 (s, 12 H, Me); 3.90 (s, 2 H, OН);
7.70—7.80 (m, 2 H, Н(6), H(7));
1675 sh,
(decomp.,
ethanol)
140—141
(decomp.,
CHCl3—
hexane)
2200 (С≡С)
1675 sh,
1715 (С=О);
2230 (С≡С);
3470 br,
74.42 5.54
74.52 5.63
8.00—8.10 (m, 2 H, Н(5), H(8))
3610 (ОН)
1675 (С=О);
2220 (С≡С)
5e
78—80
(benzene— 75.41 6.33
hexane)
75.16 6.23
—
C22H22O4
1.58 (s, 12 H, Me); 3.50 (s, 6 H, OMe);
7.70—7.80 (m, 2 H, Н(6), H(7));
8.05—8.15 (m, 2 H, Н(5), H(8))
12а
186—187
(decomp.,
ethanol)
76.17 4.06 4.40
76.18 4.16 4.44
C20H13NO3 2.33 (s, 3 H, COMe); 7.10—7.40 (m, 3 H,
2 H Phm, 1 Н Php); 7.50—7.65 (m, 2 H, 2 Н
Pho); 7.70—7.80 (m, 2 H, Н(6), H(7)); 7.99 (s,
1 H, NH); 8.05—8.20 (m, 2 H, Н(5), H(8))
C17H15NO4 1.24 (s, 6 H, Me); 2.29 (s, 3 H, COMe);
7.65—7.85 (m, 2 H, Н(6), H(7)); 7.98 (s, 1 H,
NH); 8.05—8.15 (m, 2 H, Н(5), H(8))
1660 (C=O);
1720 (NС=О);
2205 (С≡С);
3375 (NН)
1670 (C=O);
1725 (NС=О);
2215 (С≡С);
3380 (NН);
3500 (ОН)
12d
13
172—173
(decomp.,
CHCl3—
hexane)
68.70 5.05 4.95
68.68 5.09 4.71
195.5—196.5 79.63 4.30 3.65
C26H17NO3 2.16 (s, 3 H, COMe); 7.30—7.55 (m, 10 H,
Ph); 7.70—7.80 (m, 2 H, Н(6), H(7));
1680 (C=O);
2195 (С=С)
(decomp.,
CHCl3—
ether)
79.78 4.38 3.58
8.05—8.20 (m, 2 H, Н(5), H(8))

Substitution of halogen in quinones
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 7, July, 2005
1689
quinone (4а) (method А) from 2,3ꢀdibromonaphthoquinone (2)
(1.00 g, 3.2 mmol), phenylacetylene (6а) (1.00 g, 10 mmol),
CuI (1.30 g, 6.8 mmol), and Et3N (0.70 g, 8.0 mmol, 0.95 mL)
in the presence of Pd(PPh3)2Cl2 (8 mg) in a mixture of DMSO
(10 mL) and CHCl3 (5 mL) (40—42 °C, 40 min); yield 0.60 g
(53%) (see Table 1).
B. Dibromide 2 (6.00 g, 19.0 mmol) was condensed with
cuprous phenylacetylide (3а) (7.60 g, 46.0 mmol) in the presꢀ
ence of Pd(PPh3)2Cl2 (60 mg) in DMSO (60 mL) at 40—42 °C
for 50 min to give 2.30 g (34%) of 5a.
2,3ꢀDi(3ꢀhydroxyꢀ3ꢀmethylbutynyl)ꢀ1,4ꢀnaphthoquinone
(5d). The compound was prepared from dibromide 2 (1.60 g,
5.1 mmol), 2ꢀmethylbutꢀ3ꢀynꢀ2ꢀol (6d) (1.60 g, 19.0 mmol,
1.85 mL), CuI (2.50 g, 13.1 mmol), Et3N (1.10 g, 10.9 mmol,
1.48 mL), and Pd(PPh3)2Cl2 (15 mg) in a mixture of DMSO
(20 mL) and CHCl3 (15 mL) (50 °C, 130 min). The crude
product was dissolved in CHCl3 and precipitated with hexane;
the yield of glycol 5d was 0.80 g (49%) (see Table 1).
2,3ꢀDi(3ꢀmethoxyꢀ3ꢀmethylbutynyl)ꢀ1,4ꢀnaphthoquinone
(5e) was prepared similarly to diacetylene 5d from dibromide 2
(2.40 g, 7.6 mmol) and 2ꢀmethoxyꢀ2ꢀmethylbutyne (6e) (2.90 g,
30 mmol) (50 °C, 4 h). Yield 1.06 g (40%) (see Table 1).
2,5ꢀDi(phenylethynyl)ꢀ1,4ꢀbenzoquinone (8). Catalyst
Pd(PPh3)2Cl2 (6 mg) was dissolved in a mixture of DMSO
(10 mL) and CHCl3 (10 mL) at 55 °C under argon, the solution
was cooled to 20 °C, diiodide 7 (0.50 g, 13.9 mmol) and cuprous
phenylacetylide 3а (0.60 g, 36.4 mmol) were added, and the
mixture was stirred for 20 min, while its temperature rose sponꢀ
taneously to 28 °C. Diacetylene 8 (0.36 g, 84%) was isolated by
the usual procedure, m.p. ~238—240 °C (with decomp., CCl4).7
2ꢀAcetylaminoꢀ3ꢀphenylethynylꢀ1,4ꢀnaphthoquinone (12a)
was prepared similarly to acetylenylquinone 4а from 2ꢀacetylꢀ
aminoꢀ3ꢀbromoꢀ1,4ꢀnaphthoquinone (9) (2.90 g, 10.0 mmol)
phenylacetylene (6а) (1.50 g, 15.0 mmol), CuI (3.00 g,
15.7 mmol), Et3N (1.30 g, 12.9 mmol, 1.75 mL), and
Pd(PPh3)2Cl2 (30 mg) in a mixture DMSO (50 mL) and CHCl3
(35 mL) (20—22 °C, 75 min); yield 2.50 g (81%) (see Table 1).
2ꢀAcetylaminoꢀ3ꢀ(3ꢀhydroxyꢀ3ꢀmethylbutynyl)ꢀ1,4ꢀnaphthoꢀ
quinone (12d) The reaction of bromide 9 (1.20 g, 3.0 mmol) and
2ꢀmethylbutꢀ3ꢀynꢀ2ꢀol (6d) (0.60 g, 7.1 mmol, 0.7 mL) under
conditions used in the synthesis of acetylenylquinone 12а (reacꢀ
tion time 45 min) gave 0.60 g (50%) of compound 12d (see
Table 1).
and the reaction time was 3 h. The yield of quinone 13 was
0.32 g (41%) (see Table 1).
3ꢀPhenylethynylꢀ2ꢀethoxyꢀ1,4ꢀnaphthoquinone
(14).
3ꢀBromoꢀ2ꢀethoxyꢀ1,4ꢀnaphthoquinone (11) (0.50 g,
1.8 mmol), phenylacetylene (6а) (0.46 g, 4.5 mmol), CuI (0.95 g,
5.0 mmol), Et3N (0.36 g, 3.6 mmol, 0.48 mL), and Pd(PPh3)2Cl2
(8 mg) in DMSO (10 mL) and CHCl3 (6.5 mL) were stirred for
3.5 h at 36—37 °C, phenylacetylide 3а (0.45 g, 2.7 mmol) was
added, and the mixture was stirred for additional 2 h. Chromaꢀ
tography on Аl2O3 in CHCl3 followed by crystallization from a
mixture of ether and hexane gave 0.18 g (34%) of compound 14,
m.p. 105.5—106 °C (from a CHCl3—EtOH mixture).8
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2ꢀNꢀAcetyl(phenylamino)ꢀ3ꢀphenylethynylꢀ1,4ꢀnaphthoꢀ
quinone (13). 2ꢀNꢀAcetyl(phenylamino)ꢀ3ꢀbromoꢀ1,4ꢀnaphthoꢀ
quinone (10) (0.74 g, 2.0 mmol) was condensed with acetylene
6а (0.41 g, 4.0 mmol) using the same reactant and solvent ratios
as in the preparation of 12а; the reaction temperature was 36 °C
11. E. Negishi and L. Anastasia, Chem. Rev., 2003, 103, 1979.
Received March 9, 2005;
in revised form June 7 2005