Synthesis of diindeno-fused 4H-cyclopenta[def]phenanthren-4-ones and related compounds via benzannulated enediynyl propargylic alcohols

Article abstract of DOI:10.1021/jo047745y

(Chemical Equation Presented) Treatment of propargylic diols 5-7 with thionyl chloride promoted a cascade sequence of reactions leading to dichlorides 10-12 and, after reduction with tributyltin hydride, the diindeno-fused 4H-cyclopenta[def]phenanthrenes

Full text of DOI:10.1021/jo047745y

Condensation between 1 and 2 equiv of 3 led to
propargylic diol 5 as a mixture of the trans and cis
isomers. Treatment of trans-5 with thionyl chloride then
promoted a cascade sequence of reactions involving
initially two SNi′ reactions to produce in situ the benz-
Synthesis of Diindeno-Fused
4H-Cyclopenta[def]phenanthren-4-ones and
Related Compounds via Benzannulated
Enediynyl Propargylic Alcohols
annulated chloroenyne-allene
8 as described pre-
Xiaoqing Han, Yanzhong Zhang, and Kung K. Wang*
viously.1b,c,e Two subsequent formal Diels-Alder reac-
tions, presumably with each involving a Schmittel cy-
clization reaction to form the corresponding biradical1i-k
followed by an intramolecular radical-radical coupling
reaction, then gave 9, which in turn underwent two
prototropic rearrangements to furnish the diindeno-fused
4H-cyclopenta[def]phenanthrene derivative 10. Because
the relative reaction rates of the steps of the cascade
sequence have not been determined, it is also possible
that the first unit of the benzannulated enediynyl pro-
pargylic alcohol moiety could undergo a formal Diels-
Alder reaction and a prototropic rearrangement before
the second unit would begin its cyclization sequence.
Dichloride 10 is prone to hydrolysis as observed previ-
ously in related compounds.1b,c It was operationally
convenient to reduce the crude product of 10 without
further purification with tributyltin hydride to furnish
13 in 46% overall yield from trans-5. Hydrolysis of the
dimethyl ketal group then gave the diindeno-fused 4H-
cyclopenta[def]phenanthren-4-one 16. Similarly, 17 bear-
ing two additional 1,1,3,3-tetramethylbutyl (t-Oct) sub-
stituents was synthesized by treatment of either trans-6
or cis-6, prepared from condensation between 1 and 4,
with thionyl chloride followed by reduction and hydroly-
sis. Compared to 16, the presence of the two t-Oct
substituents in 17 greatly enhances its solubility in
common organic solvents. It was also possible to convert
crude dichloride 11 to diketone 18 in 45% overall yield
from trans-6 by air oxidation of 11 in the presence of a 2
M NaOH solution. By starting from 2,2-dimethyl-1,3-
indandione (2) for condensation with 3, the reaction
sequence likewise led to 15.
The success in using diols 5-7 for two cascade reaction
sequences in a single operation further demonstrates the
versatility of this synthetic pathway for the construction
of novel polycyclic aromatic structures. It is worth noting
that the diindeno-fused 4H-cyclopenta[def]phenanthrenes
13-18 have a 41-carbon framework, 38 carbons on the
aromatic rings and three carbons on the three five-
membered rings, that is represented on the surface of
C60. Several synthetic methods have been reported for
4H-cyclopenta[def]phenanthrenes,4 and a 4H-cyclopenta-
[def]phenanthrene derivative was used in the first syn-
thesis of corannulene, a bow-shaped C20H10 aromatic
hydrocarbon.4l,m
C. Eugene Bennett Department of Chemistry, West Virginia
University, Morgantown, West Virginia 26506-6045
kung.wang@mail.wvu.edu
Received December 23, 2004
Treatment of propargylic diols 5-7 with thionyl chloride
promoted a cascade sequence of reactions leading to dichlo-
rides 10-12 and, after reduction with tributyltin hydride,
the diindeno-fused 4H-cyclopenta[def]phenanthrenes 13-
15 in a single operation. Hydrolysis of 13 and 14 furnished
4H-cyclopenta[def]phenanthren-4-ones 16 and 17, respec-
tively. Air oxidation of an alkaline solution of dichloride 11
produced diketone 18.
Benzannulated enediynyl propargylic alcohols are use-
ful precursors of the corresponding enyne-allenes, which
have found applications in the synthesis of polycyclic
aromatic compounds.1 The ability of the reaction se-
quence to involve an aryl ring in a formal Diels-Alder
reaction under mild thermal conditions provides many
opportunities for the assembly of novel aromatic struc-
tures. We have successfully employed this synthetic
pathway for efficient transformations of 1,3-indandiones
12 and 23 to the diindeno-fused 4H-cyclopenta[def]-
phenanthrene derivatives 13-18 (Scheme 1).
* To whom correspondence should be addressed. Ph: (304) 293-3068,
ext 6441. Fax: (304) 293-4904.
(1) (a) Wang, K. K.; Zhang, H.-R.; Petersen, J. L. J. Org. Chem. 1999,
64, 1650-1656. (b) Zhang, H.-R.; Wang, K. K. J. Org. Chem. 1999, 64,
7996-7999. (c) Li, H.; Zhang, H.-R.; Petersen, J. L.; Wang, K. K. J.
Org. Chem. 2001, 66, 6662-6668. (d) Li, H.; Petersen, J. L.; Wang, K.
K. J. Org. Chem. 2001, 66, 7804-7810. (e) Yang, Y.; Petersen, J. L.;
Wang, K. K. J. Org. Chem. 2003, 68, 5832-5837. (f) Yang, Y.; Petersen,
J. L.; Wang, K. K. J. Org. Chem. 2003, 68, 8545-8549. (g) Dai, W.;
Petersen, J. L.; Wang, K. K. Org. Lett. 2004, 6, 4355-4357. (h) Wang,
K. K. In Modern Allene Chemistry; Krause, N., Hashmi, A. S. K., Eds.;
Wiley-VCH: Weinheim, Germany, 2004; Vol. 2, pp 1091-1126. (i)
Schmittel, M.; Strittmatter, M.; Vollmann, K.; Kiau, S. Tetrahedron
Lett. 1996, 37, 999-1002. (j) Schmittel, M.; Strittmatter, M.; Kiau, S.
Angew. Chem., Int. Ed. Engl. 1996, 35, 1843-1845. (k) Schmittel, M.;
Keller, M.; Kiau, S.; Strittmatter, M. Chem. Eur. J. 1997, 3, 807-
816.
The diacetylene 1-ethynyl-2-(phenylethynyl)benzene,
for lithiation to produce 3, was prepared as reported
previously,1d whereas diacetylene 25 for 4 was prepared
by starting from commercially available 4-t-Oct-phenol
(19) (Scheme 2). Transformation of 19 to the correspond-
(2) (a) Kuhn, R.; Trischmann, H. Chem. Ber. 1961, 94, 2258-2263.
(b) Paul, T.; Hassan, M. A.; Korth, H.-G.; Sustmann, R.; Avila, D. V.
J. Org. Chem. 1996, 61, 6835-6848.
(3) Jeong, I.-Y.; Lee, W. S.; Goto, S.; Sano, S.; Shiro, M.; Nagao, Y.
Tetrahedron 1998, 54, 14437-14454.
10.1021/jo047745y CCC: $30.25 © 2005 American Chemical Society
Published on Web 02/19/2005
2406
J. Org. Chem. 2005, 70, 2406-2408

SCHEME 1
SCHEME 2
ing triflate 20 followed by a Sonogashira reaction5 with
(trimethylsilyl)acetylene and desilylation then furnished
arylacetylene 21. Coupling of 21 with 1-bromo-2-iodo-
benzene to form 22 followed by a bromo to iodo exchange
to produce 23 for a cross-coupling reaction with (tri-
methylsilyl)acetylene and desilylation then produced 25.
Experimental Section
Propargylic Diols 6. To a solution of 2.126 g of 25 (6.772
mmol) in 15 mL of THF was added 2.57 mL of a 2.5 M solution
of n-butyllithium (6.43 mmol) in hexanes at 0 °C. The reaction
mixture was then allowed to warm to room temperature. After
30 min, a solution of 0.634 g of 1 (3.078 mmol) in 10 mL of THF
was added via cannula, and the mixture was stirred at room
temperature for 12 h. Water (15 mL) was introduced, and the
reaction mixture was concentrated to remove organic solvents.
Diethyl ether (25 mL) was added, and the organic layer was
separated, washed with water, dried over Na2SO4, and concen-
(4) (a) Yang, C. X.; Harvey, R. G. Polycyclic Aromat. Compd. 1992,
2, 229-233. (b) Harvey, R. G.; Abu-shqara, E.; Yang, C. J. Org. Chem.
1992, 57, 6313-6317. (c) Harvey, R. G. Polycyclic Aromatic Hydro-
carbons; Wiley: New York, 1997; pp 336-337. (d) Bachmann, W. E.;
Sheehan, J. C. J. Am. Chem. Soc. 1941, 63, 204-206. (e) Rutherford,
K. G.; Newman, M. S. J. Am. Chem. Soc. 1957, 79, 213-214. (f)
Medenwald, H. Chem. Ber. 1953, 86, 287-293. (g) Bhatt, T. S.; Coombs,
M. M.; Kissonerghis, A.-M. J. Chem. Soc., Chem. Commun. 1979, 433-
434. (h) Yoshida, M.; Minabe, M.; Suzuki, K. Bull. Chem. Soc. Jpn.
1983, 56, 2179-2180. (i) Minabe, M.; Yoshida, M.; Takayanagi, T. Bull.
Chem. Soc. Jpn. 1988, 61, 995-996. (j) Tomioka, H.; Kobayashi, N.
Bull. Chem. Soc. Jpn. 1991, 64, 327-329. (k) Sieglitz, A.; Schidlo, W.
Chem. Ber. 1963, 96, 1098-1108. (l) Barth, W. E.; Lawton, R. G. J.
Am. Chem. Soc. 1966, 88, 380-381. (m) Barth, W. E.; Lawton, R. G.
J. Am. Chem. Soc. 1971, 93, 1730-1745.
trated to furnish a solid residue. The residue was purified by
flash column chromatography (silica gel/50% CH2Cl2 in hexanes)
to afford 1.887 g (2.263 mmol, 74%) of trans-diol 6 and 0.251 g
(0.301 mmol, 10%) of cis-diol 6 as white solids. trans-Diol 6: mp
136-139 °C; Rf 0.20 (hexanes/CH2Cl2 ) 1:1); IR 3519, 2216, 834,
757 cm-1 1H NMR δ 7.72-7.67 (2 H, m), 7.53-7.46 (4 H, m),
;
7.41-7.36 (4 H, m), 7.32-7.21 (10 H, m) 3.87 (2 H, s), 3.81 (6 H,
s), 1.73 (4 H, s), 1.34 (12 H, s), 0.70 (18 H, s); 13C NMR δ 150.8,
142.3, 132.2, 131.9, 131.3, 129.8, 128.3, 127.6, 126.3, 126.1, 124.7,
124.3, 119.7, 109.7, 93.7, 91.7, 87.4, 86.5, 77.1, 56.8, 53.2, 38.7,
32.3, 31.8, 31.4; MS m/z 857 (MNa+), 817, 785; HRMS calcd for
C59H62O4Na (MNa+) 857.4546, found 857.4587. cis-Diol 6: Rf
(5) (a) Sonogashira, K.; Tohda, Y.; Hagihara, N. Tetrahedron Lett.
1975, 16, 4467-4470. (b) Sonogashira, K.; Yatake, T.; Tohda, Y.;
Takahashi, S.; Hagihara, N. J. Chem. Soc., Chem. Commun. 1977,
291-292. (c) Takahashi, S.; Kuroyama, Y.; Sonogashira, K.; Hagihara,
N. Synthesis 1980, 627-630.
1
0.04 (hexanes/CH2Cl2 ) 1:1); IR 3501, 2216, 834, 758 cm-1; H
J. Org. Chem, Vol. 70, No. 6, 2005 2407

NMR δ 7.84-7.78 (2 H, m), 7.56-7.49 (4 H, m), 7.45-7.39 (4 H,
m), 7.34-7.22 (8 H, m), 7.21-7.18 (2 H, m), 3.89 (3 H, s), 3.66
(3 H, s), 3.64 (2 H, s), 1.73 (4 H, s), 1.34 (12 H, s), 0.70 (18 H, s);
13C NMR δ 150.8, 142.7, 132.1, 131.9, 131.3, 130.1, 128.4, 127.6,
126.4, 126.1, 125.0, 124.7, 119.7, 109.2, 93.8, 90.8, 87.4, 87.0,
78.1, 56.7, 53.0, 52.3, 38.7, 32.3, 31.8, 31.5, 31.4; MS m/z 857
(MNa+), 817, 785; HRMS calcd for C59H62O4Na (MNa+) 857.4546,
found 857.4586.
0.592 g (0.783 mmol, 89%) of 17 as a yellow solid: compound
turns dark at 305 °C and becomes black without melting at 314
°C; Rf 0.33 (hexanes/CH2Cl2 ) 1:2); IR (KBr) 1709, 736 cm-1
;
1H NMR δ 7.50 (4 H, d, J ) 8.2 Hz), 7.34 (2 H, d, J ) 7.4 Hz),
7.27 (4 H, d, J ) 8.2 Hz), 7.18 (2 H,s), 7.11 (2 H, t, J ) 7.3 Hz),
6.89 (2 H, t, J ) 7.4 Hz), 6.69 (2 H, d, J ) 7.9 Hz), 3.99 (4 H, s),
1.88 (4 H, s), 1.49 (12 H, s), 0.88 (18 H, s); 13C NMR δ 193.6,
149.9, 143.8, 141.0, 140.6, 138.3, 137.1, 134.0, 128.7, 127.3, 126.9,
126.8, 126.4, 126.1 124.9, 123.4, 57.1, 38.6, 34.5, 32.6, 31.9, 31.8;
MS m/z 756 (M+), 685, 570; HRMS calcd for C57H56O 756.4331,
found 756.4348.
4H-Cyclopenta[def]phenanthren-4-one Dimethyl Ketal
14. To 1.625 g of trans-6 (1.948 mmol) in 15 mL of THF at 0 °C
was added via cannula a solution of 0.781 g of thionyl chloride
(6.57 mmol) and 1.058 g of anhydrous pyridine (13.38 mmol) in
10 mL of THF. The reaction mixture was then allowed to warm
to room temperature. After 8 h, the reaction mixture was
concentrated, and 20 mL of water and 30 mL of methylene
chloride were added. The organic layer was separated, washed
with water, dried over Na2SO4, and concentrated to furnish a
solid residue (crude product of dichloride 11). To a flask
containing 0.030 g (0.21 mmol) of AIBN were added a solution
of the crude product of 11 in 30 mL of benzene and 1.58 mL of
tributyltin hydride (1.71 g, 5.94 mmol). The resulting mixture
was heated at 80 °C for 18 h before it was allowed to cool to
room temperature. The mixture was treated with 20 mL of a
10% aqueous KF solution, stirred for 2 h, and filtered. The
organic layer was separated, washed with water, dried over Na2-
SO4, and concentrated to furnish a solid residue. The residue
was purified by flash column chromatography (silica gel/50%
CH2Cl2 in hexanes) to afford 0.731 g of 14 (0.911 mmol, 47%
yield from trans-6; similar result with cis-6) as a yellow solid:
compound turns dark at 268 °C and becomes black without
melting at 273 °C; Rf 0.23 (hexanes/CH2Cl2 ) 1:1); IR 1104, 822,
780, 748, 715 cm-1; 1H NMR δ 7.66-7.58 (6 H, m), 7.40 (4 H, d,
J ) 8.4 Hz), 7.38 (2 H, s), 7.27 (2 H, td, J ) 7.4, 1.0 Hz), 7.02 (2
H, t, J ) 7.5 Hz), 6.86 (2 H, d, J ) 7.9 Hz); 4.33 (4 H, s), 3.33 (6
H, s), 1.91 (4 H, s), 1.52 (12 H, s), 0.89 (18 H, s); 13C NMR δ
149.7, 144.0, 141.7, 139.8, 138.0, 135.1, 134.7, 133.7, 129.1, 126.8,
126.75, 127.71, 126.3, 125.0, 123.7, 123.6, 114.7, 57.1, 52.7, 38.6,
34.6, 32.6, 31.9, 31.8.
Diketone 18. To a solution of the crude product of dichloride
11, prepared from 0.701 g (0.841 mmol) of trans-6, in 30 mL of
THF was added 8 mL of a 2 M aqueous sodium hydroxide
solution at 0 °C. The resulting mixture was stirred at room
temperature for 24 h with a slow stream of air bubbling into
the solution. The reaction mixture was concentrated in vacuo
and then extracted with methylene chloride. The organic layer
was washed with a saturated NH4Cl solution and water, dried
over Na2SO4, and concentrated. The residue was purified by
flash column chromatography (silica gel/25% CH2Cl2 and 25%
Et2O in hexanes) to afford 0.315 g of 18 (0.380 mmol, 45% yield
from trans-6) as a yellow solid: compound turns dark at 315 °C
and becomes black without melting at 331 °C; Rf 0.14 (hexanes/
CH2Cl2/Et2O ) 1:1:1); IR (KBr) 1715, 752 cm-1; 1H NMR δ 7.74
(2 H, d, J ) 6.7 Hz), 7.61 (4 H, d, J ) 8.4 Hz), 7.36 (2 H, s), 7.34
(2 H, d, J ) 8.4 Hz), 7.22 (2 H, td, J ) 7.4, 0.7 Hz), 7.10 (2 H, td,
J ) 7.6, 1.2 Hz), 6.55 (2 H, d, J ) 7.7 Hz), 3.68 (6 H, s), 1.88 (4
H, s), 1.48 (12 H, s), 0.85 (18 H, s); 13C NMR δ 191.5, 150.7,
145.2, 139.6, 139.5, 137.4, 135.7, 135.1, 134.3, 133.0, 131.9, 129.6,
128.8, 128.7, 127.2, 127.0, 124.2, 123.9, 113.6, 57.0, 53.8, 38.7,
32.6, 31.9, 31.8; MS m/z 853 (MNa+), 807, 795; HRMS calcd for
C59H58O4Na (MNa+) 853.4233, found 853.4259.
Acknowledgment. We thank the Petroleum Re-
search Fund (38169-AC1), administered by the Ameri-
can Chemical Society, and the National Science Foun-
dation (CHE-0414063) for financial support.
4H-Cyclopenta[def]phenanthren-4-one 17. To a mixture
of 0.705 g of 14 (0.879 mmol), 30 mL of CH2Cl2, and 60 mL of
acetone was added 35 mL of a 5% HCl solution. The progress of
hydrolysis was monitored by TLC. After 19 h, the reaction
mixture was concentrated in vacuo, and 50 mL of CH2Cl2 was
added. The organic layer was separated, washed with a satu-
rated aqueous NaHCO3 solution and water, dried over Na2SO4,
and concentrated. The residue was purified by flash column
chromatography (silica gel/33% hexanes in CH2Cl2) to afford
Supporting Information Available: Experimental pro-
cedures and spectroscopic data for 5, 7, 13, 15, 16, 20-22, 24,
and 25 and 1H and/or 13C NMR spectra of compounds 5-7,
13-18, 20-22, 24, and 25. This material is available free of
charge via the Internet at http://pubs.acs.org.
JO047745Y
2408 J. Org. Chem., Vol. 70, No. 6, 2005