A simple and convenient method for the synthesis of cyclobutenediones from alkynes using new Fe(CO)5/NaH/MeI reagent system

Article abstract of DOI:10.1016/j.jorganchem.2008.05.033

Iron carbonyl complexes prepared in situ using the Fe(CO)₅/NaH/MeI reagent combination and alkynes at 25 °C give the corresponding cyclobutenediones in 50-65% yields after CuCl₂ · 2H₂O oxidation.

Full text of DOI:10.1016/j.jorganchem.2008.05.033

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Journal of Organometallic Chemistry 693 (2008) 2843–2846
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Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
A simple and convenient method for the synthesis of cyclobutenediones
from alkynes using new Fe(CO)5/NaH/MeI reagent system
*
Mariappan Periasamy , Mallesh Beesu, D. Shyam Raj
School of Chemistry, University of Hyderabad, Hyderabad 500 046, India
a r t i c l e i n f o
a b s t r a c t
Article history:
Iron carbonyl complexes prepared in situ using the Fe(CO)5/NaH/MeI reagent combination and alkynes at
25 °C give the corresponding cyclobutenediones in 50–65% yields after CuCl2 ꢀ 2H2O oxidation.
Ó 2008 Elsevier B.V. All rights reserved.
Received 17 March 2008
Received in revised form 19 May 2008
Accepted 23 May 2008
Available online 13 June 2008
Keywords:
Cyclobutenediones
Iron pentacarbonyl
Alkynes
Sodium hydride
Na/Naphthaline
THF, 25 oC
CH3COOH
25 oC
1. Introduction
Na2Fe(CO)4
Fe(CO)5
NaHFe(CO)4
CH3COONa
ð2Þ
The chemistry of metal carbonyls, especially the iron carbonyl
reagents, has been the subject of considerable interest [1]. Synthe-
sis of multifunctional molecules with reactive moieties have
spurred research activity in organometallics, particularly in the
development and use of metal carbonyl reagents [2–4]. Previously,
several organic transformations using iron carbonyls have been
developed in this laboratory [5]. The reactivity of the easily acces-
sible inexpensive but relatively less reactive Fe(CO)5 reagent can be
enhanced using several chemical promoters such as R3NO, KOMe,
R3PO, KH and NaBH4 to facilitate the CO dissociation [6,7,12]. It
has been reported that the reaction of [Et4N]HFe(CO)4 with MeI
in CH3CN leads to the formation of Fe(CO)4(CH3CN) and CH4 [8].
This method of generation of ‘‘Fe(CO)4” in situ would serve as a
simple alternate method for synthetic applications of this species
[9]. Such reactive iron carbonyl reagent systems have been previ-
ously prepared using NaHFe(CO)4 species which in turn needs to
be prepared using Fe(CO)5/NaOH in methanol [3c] or Fe(CO)5/Na/
naphthaline followed by reaction with carboxylic acids in THF
[5a] (Eqs. 1 and 2).
In continuation of these efforts on the synthesis and applications of
reactive iron carbonyls, we have developed a novel method for the
generation of ‘‘Fe(CO)4” species using the NaH, Fe(CO)5 and MeI re-
agent system through a formyl ferrate intermediate [10]. We wish
to report that the reactive iron carbonyl species prepared in situ
directly in this way further reacts with alkynes and gives an inter-
mediate that can be converted to the corresponding cyclobutenedi-
ones after oxidation with CuCl2 ꢀ 2H2O.
2. Results and discussions
We have examined the preparation of the reactive species
in situ using the readily accessible Fe(CO)5 and NaH combination
with an objective of developing a relatively less complicated proce-
dure. The Fe(CO)5 reagent reacts with NaH to give the Na[HFe
(CO)4] species [10] and the subsequent reaction with MeI is ex-
pected to produce the coordinatively unsaturated ‘‘Fe(CO)4” spe-
cies which undergoes reaction with alkynes to give the
O
NaOH
CH3OH, 25 oC
ð1Þ
[
]
Fe(CO)4
C
Fe(CO)5
NaHFe(CO)4
NaHCO3
Na H
O
corresponding
cyclobutenediones
after
oxidation
with
CuCl2 ꢀ 2H2O (Scheme 1). Several alkynes were converted to the
corresponding cyclobutenediones [11] following this procedure.
The yields of this reaction are moderate to good (50–65%). The re-
sults are summarized in Table 1.
In these reactions, the NaH (6 equiv.), Fe(CO)5 (6 equiv.) and
MeI (6 equiv.) were used in larger quantities as the initially formed
* Corresponding author. Tel.: +91 40 23134814; fax: +91 40 23012460.
E-mail address: mpsc@uohyd.ernet.in (M. Periasamy).
0022-328X/$ - see front matter Ó 2008 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2008.05.033

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M. Periasamy et al. / Journal of Organometallic Chemistry 693 (2008) 2843–2846
R
O
O
(6 equiv.)
(1 equiv.)
MeI
RC CR'
CuCl2.2H
2O
THF
NaH
+
Fe(CO)5
25 oC, 5h
25 oC, 10h
(6 equiv.)
(6 equiv.)
R'
50-65%
Scheme 1.
Table 1
H13C6
O
O
Synthesis of cyclobutenediones with Fe(CO)5/NaH/MeI reagent systema
Additive
1.
2.
Fe(CO)5 + NaH
Entry
1
Alkyne
Productb
Yieldc (%)
H
H
13C6
H
H
O
O
3. CuCl2.2H2O
THF, 25 oC
65
55
50
52
55
56
51
2a
2b
( )5
H
(%)
Yield
Additive
5
65
55
15
10
1. MeI
H
O
2. Me3SiCl
3. CH3COOH
4. PhCH2Cl
2
3
4
5
6
( )7
H
O
7
Scheme 2.
H
O
2c
( )4
Ph
H
O
4
Ph
O
‘‘Fe(CO)4” would also form dimeric and trimeric iron carbonyl
species. We have examined the use of other reagents like PhCH2Cl,
CH3COOH and Me3SiCl in the place of MeI. In these cases also the
cyclobutenediones were obtained after CuCl2 ꢀ 2H2O oxidation
but in lesser yields (10–55%) (Scheme 2).
Though, THF was found to be a suitable solvent, CH3CN also
gave comparable results. However, the use of solvents like CHCl3
and CH2Cl2 gave unidentified mixture of iron carbonyl products.
Presumably, the coordinating solvents may form weak complexes
with the coordinative unsaturated species like monomeric Fe(CO)4
or dimeric Fe2(CO)9 or Fe2(CO)8 or trimeric Fe3(CO)11 that help in
realizing cleaner reaction [5,11,12].
The formation of cyclobutenediones from the NaHFe(CO)4 and
alkynes can be explained by considering a tentative mechanism
depicted in Scheme 3. Addition of the Fe(CO)5 to the NaH in THF
would give the NaHFe(CO)4, which on reaction with MeI could gen-
erate the ‘‘Fe(CO)4 THF” along with dimeric and trimeric iron car-
bonyl spices that can further react with alkynes followed by CO
insertion to give the maleoyl complex of the type 1A or the ferrole
complex of the type 1B [5]. Such complexes could give the cyclob-
utenediones after CuCl2 ꢀ 2H2O oxidation.
2d
Ph
Ph
H
O
O
2e
2f
Ph
Ph
H
Ph
Ph
O
O
O
Ph
O
7
2g
Ph
O
a
All the reactions were carried out using Fe(CO)5 (7.5 mmol), NaH-55%
(15 mmol), MeI (7.5 mmol) and alkyne (1.25 mmol) in THF (35 mL).
b
The product was identified by spectral data (IR, 1H NMR, 13C NMR and mass)
and comparison with reported data [5].
c
Yields reported are for the isolated products and based on the amount of
alkynes used.
Fe(CO)4(THF)
MeI/THF
O
THF
NaH
THF
+
NaHFe(CO)4
Fe(CO)5
Na[H
C
Fe(CO)4]
Dimeric and trimeric
CO
CH4
complexes
O
OH
R
O
R
R
CuCl2.2H2O
RC CR'
Fe(CO)3
CO
Fe(CO)3
CO
or
R'
R'
R'
O
Fe(CO)3
O
Fe(CO)2
OH
(1A)
(1B)
(2a–2g)
Scheme 3.

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M. Periasamy et al. / Journal of Organometallic Chemistry 693 (2008) 2843–2846
2845
199.9, 196.6, 184.8, 31.2, 27.1, 25.6, 22.1, 13.7; MS (EI): m/z 151
(Mꢂ1).
3. Conclusion
Compound 2d: yield: 52%, 0.152 g; mp 95–96 °C (lit.[5,18c,18d]
We have developed a simple and convenient method for the
synthesis of cyclobutenediones using easily accessible and inex-
pensive starting resource such as NaH. The present in situ method
of preparation of coordinatively unsaturated iron carbonyl species
for synthetic applications has advantages over the erstwhile
known methods since this method avoids the use of Fe3(CO)12 or
Fe2(CO)9 which are in turn to be prepared from Fe(CO)5 [12].
Cyclobutenedione and their derivatives have been used as NLO
materials [13a], growth regulators, potassium channel openers,
drug molecules [13b,13c,13d], anion recognition systems [14], chi-
ral ligands [15] and versatile starting materials for the synthesis of
multifunctional molecules [16]. Hence, easy accessibility of these
derivatives should facilitate further research in these areas.
mp 97 °C); IR (KBr) = 1780 cmꢂ1 1H NMR: d = 8.14 (m, 4H), 7.45–
;
7.68 (m, 6H); 13C NMR: d = 196.2, 187.6, 133.5, 131.2, 129.4,
128.3; MS (EI): m/z 235 (M+1).
Compound 2e: yield: 55%, 0.108 g; mp 152–153 °C
(lit.[5,18c,18d] mp 152–153 °C); IR (KBr) = 1768 cmꢂ1 1H NMR:
;
d = 9.5 (s, 1H), 7.3–8.0 (m, 5H); 13C NMR: d = 197.7, 196.0, 195.5,
178.3, 134.6, 129.5, 129.4, 127.3; MS (EI): m/z 159 (M+1).
Compound 2f: yield: 56%, 0.120 g; mp 98–100 °C (lit. [18a] mp
98–100 °C); IR (KBr) = 1782, 1765 cmꢂ1; 1H NMR: d = 7.99 (m, 2H),
7.25-7.57 (m, 3H), 2.64 (s, 3H); 13C NMR: d = 198.4, 197.0, 193.7,
191.3, 133.5, 129.4, 128.6,12.4; MS (EI): m/z 173 (M+1). Anal. Calc.
for C11H8O2: C, 76.73; H, 4.68. Found: C, 76.66; H, 4.70%.
Compound 2g: yield: 51%, 0.118 g; mp 64–66 °C (lit. [18b] mp
62 °C); IR (KBr) = 1778, 1755 cmꢂ1 1H NMR: d = 7.93 (m, 2H),
;
4. Experimental
7.47–7.56 (m, 3H), 2.99 (q, J = 6.0 Hz, 2H), 2.1 (t, J = 6.0 Hz, 3H);
13C NMR: d = 198.7, 198.3, 197.5, 190.3, 133.5, 129.5, 128.5, 21.1,
10.3; MS (EI): m/z 187 (M+1). Anal. Calc. for C12H10O2: C, 77.40;
H, 5.41. Found: C, 77.51; H, 5.42%.
General: 1H NMR (400 MHz) and 13C NMR (100 MHz) spectra
were recorded in CDCl3 and TMS was used as reference
(d = 0 ppm). Melting points are uncorrected. IR spectra were re-
corded on a JASCO FT-5300 instrument with polystyrene as refer-
ence. Mass spectral analysis was carried out on VG 7070H mass
spectrometer using EI technique at 70 eV. Fe(CO)5 and NaH (55–
60%) supplied by Fluka and Finar, respectively. The alkynes used
in the reactions (except heptyne) were prepared by following re-
ported procedure [17]. THF was distilled over sodium benzophe-
none ketyl system. Chromatographic purification was conducted
by column chromatography using 100–200 mesh silica gel ob-
tained from Acme Synthetic Chemicals, India. All reactions and
manipulations were carried out under nitrogen atmosphere. All
the yields reported are isolated yields of materials, judged homo-
geneous by TLC analysis.
Acknowledgements
We are thankful to the CSIR (New Delhi) for financial support.
Support of the UGC under ‘‘University of Potential for Excellence”
programme is gratefully acknowledged. The award of the JC Bose
Fellowship grant to M.P. gratefully acknowledged.
References
[1] (a) J.J. Brunet, Chem. Rev. 90 (1990) 1041;
(b) K. Khumtaveeporn, H. Alper, Acc. Chem. Res. 28 (1995) 414;
(c) L.S. Liebeskind, S.L. Baysdon, M.S. South, S. Iyer, J.P. Leeds, Tetrahedron 41
(1985) 5839.
[2] (a) A.J.J. Fatiadi, Res. Natl. Inst. Stand. Technol. 96 (1991) 1;
(b) N.E. Shore, Chem. Rev. 88 (1988) 1081;
4.1. Preparation of cyclobutenedione using the Fe(CO)5/NaH/MeI
reagent system
(c) R. Noyori, Y. Hayakawa, Tetrahedron 41 (1985) 5879;
(d) C.W. Bird, Chem. Rev. 62 (1962) 283.
[3] (a) W. Hubel, in: I. Wender, P. Pino (Eds.), Organic Synthesis via Metal
Carbonyls, vol. 1, Wiley-Interscience, New York, 1968, p. 273. and references
cited therein;
The Fe(CO)5(1.45 g, 7.5 mmol) was added dropwise to the NaH
(0.33 g, 7.5 mmol) in THF (35 mL) at 25 °C under dry nitrogen.
And stirred for another 5 h at same temperature. The above reac-
tion mixture was treated with CH3I (1.06 g, 7.5 mmol) at 0 °C under
dry N2 atmosphere. After 10 min diphenylacetylene (0.22 g,
1.25 mmol) was added and further stirred for 10 h at room temper-
ature. The metal carbonyl complexes were oxidised using
CuCl2 ꢀ 2H2O (2.5 g, 15 mmol) in acetone (10 mL). Saturated NaCl
solution was added and the contents were extracted with ether
(2 ꢁ 40 mL). The combined extracts were washed successfully with
saturated Na2S2O3 solution and brine, dried over anhydrous
Na2SO4 and concentrated under reduced pressure. The residue
was subjected to column chromatography (silica gel, hexane–
EtOAc). Ethyl acetate (2%) in hexane eluted the 3,4-diphenyl-3-cyc-
lobutene-1,2-dione 2d.
(b) W.R. Fehlhammer, H. Stolzenberg, in: G. Wilkinson, F.G.A. Stone, E.W. Abel
(Eds.), Comprehensive Organometallic Chemistry, vol. 4, Pergamon Press,
Oxford, 1983, p. 545;
(c) R. Noyori, I. Umeda, T. Ishigami, J. Org. Chem. 37 (1972) 1542.
[4] (a) A.J. Pearson, R.J. Shively Jr., R.A. Dubbert, Organometallics 11 (1992) 4096;
(b) A.J. Pearson, R.J. Shively Jr., Organometallics 13 (1994) 578;
(c) A.J. Pearson, A. Perosa, Organometallics 14 (1995) 5178;
(d) A.J. Pearson, M.W. Zettler, J. Am. Chem. Soc. 111 (1989) 3908;
(e) H.J. Knölker, J. Heber, C.H. Mahler, Synlett (1992) 1002;
(f) H.J. Knölker, J. Heber, Synlett (1993) 924;
(g) H.J. Knölker, C. Simon, Tetrahedron Lett. 41 (2000) 5035;
(h) H.J. Knölker, B. Arnold, J.B. Dirk, G.J. Peter, P. Holger, Tetrahedron Lett. 40
(1999) 8075;
(i) H.J. Knölker, B. Elke, J. Heber, Tetrahedron Lett. 36 (1995) 7647;
(j) H.J. Knölker, Chem. Rev. 100 (2000) 2941.
[5] (a) M. Periasamy, U. Radhakrishnan, J.J. Brunet, R. Chauvin, A.W. El-Zaizi, J.
Chem. Soc., Chem. Commun. (1996) 1499;
Compound 2a: yield: 65%, 0.135 g; IR (neat) = 1784 cmꢂ1 1H
;
(b) M. Periasamy, C. Rameshkumar, Tetrahedron Lett. 41 (2000) 2719;
(c) M. Periasamy, A. Devasagayaraj, U. Radhakrishnan, Organometallics 12
(1993) 1424;
NMR: d = 9.24 (s, 1H), 2.72 (t, J = 6.0 Hz, 2H), 1.32–1.67 (m, 2H),
1.22–1.30 (m, 6H), 0.79 (t, J = 8 Hz, 3H); 13C NMR: d = 208.4,
200.1, 196.7, 185.0, 31.2, 28.8, 27.4, 25.8, 22.3, 13.7; MS (EI): m/z
167 (M+1).
(d) M. Periasamy, A. Mukkanti, D. Shyam Raj, Organometallics 23 (2004) 619.
[6] (a) J. Pearson, J. Cooke, J. Takats, R.B. Jordan, J. Am. Chem. Soc. 120 (1998) 1434.
and the references cited therein;
(b) Y. Shvo, E. Hazum, Chem. Commun. (1974) 336;
Compound 2b: yield: 55%, 0.133 g; IR (neat) = 1786 cmꢂ1 1H
;
(c) J.H. Eekhof, H. Hogeveen, R.M. Kellogg, Chem. Commun. (1976) 657.
[7] (a) B.F.G. Johnson, J. Lewis, D.A. Pippard, J. Chem. Soc., Dalton Trans. (1981) 407;
(b) H.J. Knölker, Chem. Soc. Rev. 28 (1999) 51.
[8] K.H. Whitmire, T.R. Lee, E.S. Lewis, Organometallics 5 (1986) 987.
[9] (a) M. Poliakoff, J.J. Turner, J. Chem. Soc., Dalton Trans. (1974) 2276;
(b) J.D. Black, P.S. Braterman, J. Organomet. Chem. 85 (1975) C7;
(c) V.V. Kane, J.R.C. Light, M.C. Whiting, Polyhedron 4 (1985) 553.
[10] J.C. Bricker, W.P. Martin, S.G. Shore, Organometallics 6 (1987) 2545.
[11] (a) M. Periasamy, C. Rameshkumar, U. Radhakrishnan, J.J. Brunet, J. Org. Chem.
63 (1998) 4930;
NMR: d = 9.22 (s, 1H), 2.71 (t, J = 8.0 Hz, 2H), 1.63–1.67 (m, 2H),
1.20–1.25 (m, 10H), 0.79 (t, J = 8.0 Hz, 3H); 13C NMR: d = 208.4,
200.1, 196.7, 184.9, 31.9, 29.2, 29.0, 28.9, 27.5, 25.9, 22.6, 13.9;
MS (EI): m/z 195 (M+1).
Compound 2c: yield: 50%, 0.095 g; IR (neat) = 1786 cmꢂ1 1H
;
NMR: d = 9.20 (s, 1H), 2.81 (t, J = 7.3 Hz, 2H), 1.70–1.83 (m, 2H),
1.27–1.40 (m, 4H), 0.82 (t, J = 7.3 Hz, 3H); 13C NMR: d = 208.3,

Evaluation Only. Created with Aspose.PDF. Copyright 2002-2021 Aspose Pty Ltd.
2846
M. Periasamy et al. / Journal of Organometallic Chemistry 693 (2008) 2843–2846
(b) M. Periasamy, C. Rameshkumar, U. Radhakrishnan, Tetrahedron Lett. 38
(1997) 7229;
(b) R. Prohens, G. Martorell, P. Ballester, A. Costa, Chem. Commun. (2001)
1456.
(c) C. Rameshkumar, M. Periasamy, Organometallics 19 (2000) 2400;
(d) M. Periasamy, A. Mukkanti, D. Shyam Raj, Organometallics 23 (2004)
6323.
[15] J. Zhang, H.-B. Zhou, S.-M. Lü, M.-M. Luo, R.G. Xie, M.C.K. Choi, Z.-Y. Zhou, S.C.
Chan, T.-K. Yang, Tetrahedron Asymmetry 12 (2001) 1907.
[16] (a) L.S. Liebeskind, S.L. Baysdon, M.S. South, J. Am. Chem. Soc. 102 (1980)
7397;
[12] (a) Y. Shvo, E. Hazum, Chem. Commun. (1975) 829;
(b) J. Elzinga, H. Hogeveen, Chem. Commun. (1977) 705.
[13] (a) K.Y. Law, F.C. Bailey, J. Org. Chem. 57 (1992) 3278;
(b) M. Abou-Gharbia et al., J. Med. Chem. 41 (1998) 236;
(c) A.M. Gilbert et al., J. Med. Chem. 43 (2000) 1203;
(d) B. Bang-Andersen, H. Ahmadian, S.M. Lenz, T.B. Stensbøl, U. Madsen, K.P.
Bogeso, P. Krogsgaard-Larsen, J. Med. Chem. 43 (2000) 4910.
[14] (a) S. Tomas, R. Prohens, G. Deslongchamps, P. Ballester, A. Costa, Angew.
Chem., Int. Ed. 38 (1999) 2208;
(b) L.S. Liebeskind, D. Mitchell, B.S. Foster, J. Am. Chem. Soc. 109 (1987) 7908;
(c) L.D. Foland, J.O. Karlsson, S.T. Perri, R. Schwabe, S.L. Xu, S. Patil, H.W.
Moore, J. Am. Chem. Soc. 111 (1989) 975.
[17] E.V. Dehmlow, M. Lissel, Tetrahedron 37 (1981) 1653.
[18] (a) L.S. Liebeskind, Tetrahedron Lett. 31 (1990) 4293;
(b) W. Ried, Liebigs Ann. Chem. 2 (1982) 355;
(c) L.S. Liebeskind, S.L. Baysdon, Tetrahedron Lett. 25 (1984) 1747;
(d) M.S.A. Parker, C.J. Rizzo, Synth. Commun. 25 (1995) 2781.