Towards the catalytic formation of α,β-vinylesters and alkoxy substituted γ-lactones

Article abstract of DOI:10.1016/j.jorganchem.2010.08.036

A facile, one pot, high yield synthesis of α,β-vinylester (1-14) and alkoxy substituted γ-lactones (15-28) has been achieved by the photochemical reaction of terminal acetylene (ferrocenyl phenyl trimethylsillyl, hexyl and cyclohexyl) with alcohol (methanol, ethanol and isopropanol) and carbon monoxide in presence of iron pentacarbonyl as a catalyst. The selectivity of the compounds depends on the time of photolysis of the reaction as well as the solvent used. A stable reaction intermediate ferrole was isolated, and further photolysis with alcohols, resulted in the formation of α,β-vinylester. All the compounds were fully characterised by spectroscopic methods and the molecular structures of compounds 1, 16, 17 and 20 were established crystallographically.

Full text of DOI:10.1016/j.jorganchem.2010.08.036

Journal of Organometallic Chemistry 695 (2010) 2687e2694
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Towards the catalytic formation of
-lactones
a,b-vinylesters and alkoxy substituted
g
,
b,
c
,
a
a
a
b
Pradeep Mathur a
, Raj Kumar Joshi , Badrinath Jha , Amrendra K. Singh , Shaikh M. Mobin
*
a Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
b National Single Crystal X-ray Diffraction Facility, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
c School of Sciences, Indian Institute of Technology Indore, Khandwa Road, Indore 452017, India
a r t i c l e i n f o
a b s t r a c t
Article history:
A facile, one pot, high yield synthesis of
a
,
b
-vinylester (1e14) and alkoxy substituted
g
-lactones (15e28)
Received 5 August 2010
Received in revised form
20 August 2010
Accepted 24 August 2010
Available online 23 September 2010
has been achieved by the photochemical reaction of terminal acetylene (ferrocenyl phenyl trimethylsillyl,
hexyl and cyclohexyl) with alcohol (methanol, ethanol and isopropanol) and carbon monoxide in
presence of iron pentacarbonyl as a catalyst. The selectivity of the compounds depends on the time of
photolysis of the reaction as well as the solvent used. A stable reaction intermediate ferrole was isolated,
and further photolysis with alcohols, resulted in the formation of a,b-vinylester. All the compounds were
fully characterised by spectroscopic methods and the molecular structures of compounds 1, 16, 17 and 20
were established crystallographically.
Keywords:
a
,
b-Vinylester
Ó 2010 Elsevier B.V. All rights reserved.
g-Lactones
Iron pentacarbonyl
Photolysis
Catalysis
1. Introduction
precursors. Compounds containing these units are highly efficient
in antitumor activity, [11,12] intestinal carcinogenesis inhibition
Catalytic synthesis of vinylesters and lactones from oxidative
carbonylation of terminal acetylenes is of great significance as these
are important building blocks in synthetic chemistry [1]. A wide
variety of products resulting from the mono- and dicarbonylation
of terminal acetylenes have been obtained from such reactions,
using some Pd(II) complexes as catalyst [2,3].
[13] antifungal activities, [14] and significantly active against
lymphatic leukemia [15] as well as HIV-1 protease inhibition [16].
a,b-Vinylester derivatives of ferrocene are used in the design of
organometallic liquid crystals [17], electrochemical redox-recep-
tors, SAM-forming substances, propellants and in asymmetric
catalysis [18], Ferrocenes with open-arms having ene-backbones,
and functionalized chromophores [19] are known for their NLO and
redox switching properties [20].
In spite of obvious economic advantage, until recently, iron-
catalyzed processes were rare in organic synthesis. However,
within the last few years, there have been a number of reports on
the potential of iron catalysis for reduction, oxidation and coupling
reactions [21,22]. Periasamy et al. [23,24] have worked and repor-
ted extensively on stoichiometric carbonylation of alkynes. We
have been involved in the investigation of reactivity of ferrocenyl
substituted terminal and internal acetylenes towards simple metal
carbonyl complexes under varying reaction conditions [25]. Very
recently, we observed the formation of ferrocenyl substituted esters
formed as a result of addition of CO and MeOH to 1,3-diynes sup-
ported on carbonyl cluster [26]. In this paper we report the
photochemical reaction of different terminal acetylenes (ferro-
cenyl, phenyl, trimethylsillyl, cyclohexyl, and hexyne) with three
different alcohols (methanol, ethanol and isopropanol) and CO in
Although several methods exist for the preparation of g-lactones
[4], they suffer from limitation of being multistep or weakly feasible.
Also, the reactants need to be selected such that they contain easily
cyclisable functionalities. Takashi et al. [5] reported a single step
synthesis of
high pressure (100 atm) of CO and Rh6(CO)16 catalyst; however, the
yields are rather modest. Synthesis of -unsaturated esters can be
g-lactone, where ethyne undergoes lactonisation under
a,b
carried out by Heck reaction [6,7], transesterification [8] and a range
of other methods [9,10]. However, none of these offer a single step
approach towards conversion of terminal acetylene to a,b-unsatu-
rated vinylesters. The lactone ring [furan-2(5H)-one (but-2-en-4-
olide)] is an important bioactive component in several medicinal
* Corresponding author. Department of Chemistry, Indian Institute of Technology
Bombay, Powai, Mumbai 400076, India. Tel.: þ9122 25767180; fax: þ9122 25767152.
E-mail address: mathur@iitb.ac.in (P. Mathur).
0022-328X/$ e see front matter Ó 2010 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2010.08.036

2688
P. Mathur et al. / Journal of Organometallic Chemistry 695 (2010) 2687e2694
trend is observed (Table 1). These observations can be utilized to
improve the yield of a particular type of compound selectively by
careful tuning of reaction conditions. For example, the best yield for
ester (FcC2H2CO2CH3, 89%) can be achieved using methanol as
solvent and a short duration of photolysis (30 min). Similarly, for
lactones, the best yield (88%) is obtained when isopropanol is used
as a solvent and photolysis carried out for 3 h.
Scheme 1. Formation of a,b-vinylester and lactones.
All compounds were characterized by IR, 1H and 13C NMR
spectroscopy, mass spectrometry and elemental analyses. Molec-
ular structures of compounds 1, 16, 17 and 20 were confirmed by
single crystal X-ray diffraction technique. All esters show the
characteristic CO stretching in the range 1633e1754 cmꢀ1. In
lactones, the CO stretching varies from 1619e1799 cmꢀ1. 1H NMR
presence of catalytic amount (1.7 mol%) of iron pentacarbonyl,
which leads to the formation of
in a single step.
a,b-vinylester and alkoxy g-lactone
2. Results and discussions
spectra of esters show peaks for vinylic protons at
d 7.40e7.71 and
Photolysis of a solution of terminal acetylene (ferrocenyl,
phenyl, trimethylsilyl, cyclohexyl, hexyne), alcohols (methanol,
ethanol and isopropanol) and CO in presence of Fe(CO)5 resulted in
d
6.45e6.94. The coupling constants of the vinylic protons for
compounds 4, 7, 8, 9, and 10 was observed between J ¼ 3.1e7.8 Hz,
indicative of a cis configuration of hydrogen atom around the
the formation of ferrocenyl/alkyl/aryl substituted
a,b-vinylester
p-electron cloud, whereas, for the remaining vinylesters, having
(1e14), and alkoxy -lactone (15e28) (Scheme 1). In the reactions
g
J ¼ 13.4e16.2 Hz, a trans configuration of H atoms around the
of phenylacetylene with alcohols, formation of diphenylquinone
was also observed in trace amount. Similar reactions in presence of
other metal carbonyls, M(CO)6 (M ¼ Mo, Cr, W), Ru(CO)5 and
Ru3(CO)12 did not give these products. Use of visible light in place of
UV decreased the yield of esters and lactones. Improved yield of
esters and lactones were observed when the photolysis reactions
were carried out under continuous bubbling of CO and 1.7 mol% of
Fe(CO)5. In the absence of Fe(CO)5, and prolonged photolysis of
alcoholic solution of terminal acetylene (except ferrocenyl acety-
lene) with continuous CO bubbling did not yield vinylesters and
lactones. In the case of photolysis of ferrocenylacetylene with
alcohols in CO presence, some decomposition occurs and liberated
Fe2þ probably functions as a catalyst, resulting in formation of trace
amounts of the vinylester and lactone (less than 10% and 5%
respectively). In general, yields of ferrocenyl substituted esters and
lactones are better than those of the alkyl/aryl substituted ones.
Yields of esters and lactones are susceptible to the type of
alcohol as well as duration of UV irradiation (Table 1). The yield of
lactones increases and that of ester decreases with increasing
reaction time. The yield of esters vary for the alcohols as
methanol > ethanol > isopropanol. In case of lactones, a reverse
olefinic bond is suggested. In lactones the vinylic proton signals
were observed in the range
signal appears at 6.02e6.34. Signals for ferrocenyl, phenyl,
d
5.96e6.34, while the CH(OR0) proton
d
cyclohexyl, TMS, and butyl groups protons were observed at their
usual positions.
Molecular structure of 1 is shown in Fig. 1. The ferrocenyl group
is trans to COOR0 group. The CeC bond lengths C(2)eC(3) ¼ 1.465(6)
Å, C(3)eC(4) ¼ 1.318(6) Å and C(4)eC(5) ¼ 1.442(6) Å indicate
delocalization of electrons over the four carbon atoms and ferro-
cenyl group. Molecular structure of 16 and 17 (Figs. 2 and 3)
consists of a lactone ring with ferrocenyl group at position 3 and
alkoxy group at position 4 and 2, respectively, while in compound
20 (Fig. 4), the phenyl group is at position 3 and alkoxy group at
position 11. In all lactones, both ferrocenyl/phenyl and OR0 groups
are on the same side of the lactone ring.
In earlier work [27], we have shown that the photochemical
reaction of Fe(CO)5, ferrocenylacetylene and CO in hexane solvent
forms diferrocenyl quinone and the reaction proceeds via the fer-
role intermediate, [Fe{C(O)C(H)C(Fc)C(O)}(CO)4]. Trace amount of
quinone formed in our present reaction of acetylene with alcohol
and CO in presence of Fe(CO)5 suggested that here too perhaps
a ferrole intermediate might be involved. Indeed, when we inves-
tigated the reaction of ferrole [Fe{C(O)C(H)C(Fc)C(O)}(CO)4] with
alcohol, we observed a total transformation to vinylesters in all
cases, and therefore, the formation of vinylester can be shown to
proceed according to the steps depicted in Scheme 2. It can be
argued that ferrole to ester conversion is relatively faster than the
quinone formation due to high concentration of alcohol (solvent).
The ferrole to quinone conversion becomes significant when the
reaction is carried out with visible light irradiation at room
Table 1
Fe(CO)5 catalyzed esterification and lactonization by addition of CO and alcohols to
the terminal acetylene.
Run Acetylene
(7.5 mmol)
Solvent Photolysis (0.5 h)a,b
Photolysis
(3 h)a,b
Ester
Lactone
Ester Lactone
(Compound no.) (Compound no.)
temperature. Involvement of
a carbene intermediate in the
1
2
3
4
5
6
7
8
9
FcC^CH
FcC^CH
FcC^CH
PhC^CH
PhC^CH
PhC^CH
MeOH 89 (1)
7 (15)
28 (16)
35 (17)
9 (18)
37
23
8
60
74
88
59
63
71
71
67
82
52
76
76
60
79
formation of alkoxy lactone has been proposed in literature [28].
We suggest that a carbene intermediate is involved in our reaction
also leading to the formation of alkoxy lactones, as depicted in
Scheme 3.
EtOH
61 (2)
49 (3)
iPrOH
MeOH 57 (4)
34
29
23
26
31
17
29
21
12
32
15
EtOH
48 (5)
40 (6)
10 (19)
27 (20)
12 (21)
16 (22)
32 (23)
12 (24)
19 (25)
25 (26)
14 (27)
31 (28)
iPrOH
TMSC^CH MeOH 54 (7)
3. Conclusion
TMSC^CH EtOH
47 (8)
44 (9)
TMSC^CH iPrOH
10 C4H9C^CH MeOH 58 (10)
In conclusion, we have demonstrated a one pot synthesis of
a,b-vinylesters and alkoxy substituted lactones using iron penta-
11 C4H9C^CH EtOH
44 (11)
51 (12)
12 C4H9C^CH iPrOH
carbonyl as catalyst. Our facile method, contrasts with a related
use of Fe(CO)5 or Fe3(CO)12 as catalyst for the formation of succi-
nimides by reaction of alkynes with ammonia or amines with CO
at high temperature and pressure [29], and may find general
utility in the synthetic methodology of these important organic
compounds.
13 C6H11C^CH MeOH 66 (13)
14 C6H11C^CH iPrOH
45 (14)
Yields are based on the amount of acetylene reacted.
a
In presence of 1.7 mol% of Fe(CO)5,
Continuous CO bubbling. Fc ¼ ferrocenyl, Ph ¼ phenyl, TMS ¼ trimenthylsilyl,
b
C4H9e ¼ n-butyl, C6H11e ¼ cyclohexyl.

P. Mathur et al. / Journal of Organometallic Chemistry 695 (2010) 2687e2694
2689
Fig. 1. ORTEP diagram of Methyl-3-ferrocenyl-2-propenoate (1) with 50% probability ellipsoids, Selected bond distances [Å] and angles [deg]: C(9)eC(5): 1.433(6), O(1)eC(2):
1.340(5), O(1)eC(1): 1.434(5), C(3)eC(4): 1.318(6), C(3)eC(2): 1.465(6), C(2)eO(2): 1.202(5), C(5)eC(6): 1.428(6), C(5)eC(4): 1.442(6); C(2)eO(1)eC(1): 115.3(4), C(4)eC(3)eC(2):
120.2(4), O(2)eC(2)eO(1): 122.7(4), O(2)eC(2)eC(3): 126.2(4), O(1)eC(2)eC(3): 111.1(4), C(6)eC(5)eC(9): 107.6(4), C(6)eC(5)eC(4): 128.5(4), C(9)eC(5)eC(4): 123.7(4), C(3)eC
(4)eC(5): 126.2(5).
4. Experimental
pentacarbonyl (97% pure) was purchased from Fluka. Phenyl-
acetylene, cyclohexylacetylene and 1-hexyne were purchased from
Aldrich. Trimethylsilylacetylene was purchased from Spectrochem
Ltd. Ferrocenylacetylene was prepared using reported method [30].
TLC plates were purchased from Merck (20 ꢁ 20 cm, silica gel 60
F254). Solvents were purchased from Merck and used after purifi-
cation and drying under argon atmosphere.
4.1. General procedures
Reactions and manipulations were performed using standard
Schlenk line technique under argon/nitrogenwith a slightly positive
pressure. Photochemical reactions were carried out in cooled double
walled quartz vessel having a 125-W immersion type mercury lamp
manufactured by Applied Photophysics Ltd. Infrared spectra were
recorded on Thermo-Nicolet 380 FTIR spectrometer as hexane and
dichloromethane solutions in 0.1 mm path length of NaCl, NMR
spectra on VARION VXRO-400S spectrometer in CDCl3. Elemental
analysis was performed on a Carlo-Erba automatic analyzer. Iron
4.2. Crystal structure determination
Suitable X-ray quality crystals of compounds
1
(0.34
ꢁ
0.32 ꢁ 0.28 mm3), 16 (0.34 ꢁ 0.30 ꢁ 0.26 mm3), 17 (0.28 ꢁ
0.23 ꢁ 0.19 mm3) and 20 (0.32 ꢁ 0.28 ꢁ 0.15 mm3) were grown by
Fig. 2. ORTEP diagram of 3-ferrocenyl-4-ethoxy-2-butenolide (16) with 50% probability ellipsoids, Selected bond distances [Å] and angles [deg]: O(1)eC(1): 1.205(3), O(2)eC(1):
1.374(3), O(2)eC(2): 1.457(3), O(3)eC(2): 1.383(3), O(3)eC(5): 1.456(3), C(1)eC(4): 1.460(4), C(2)eC(3): 1.511(3), C(3)eC(4): 1.340(4), C(3)eC(7): 1.444(3), C(5)eC(6): 1.502(4), C(7)e
C(8): 1.434(3), C(7)e(11): 1.443(3); C(1)eO(2)eC(2): 108.89(19), C(2)eO(3)eC(5): 114.35(18), O(1)eC(1)eO(2): 121.0(3), O(1)eC(1)eC(4): 130.5(3), O(2)eC(1)eC(4): 108.6(2),
O(3)eC(2)eO(2): 110.7(2), O(3)eC(2)eC(3): 110.7(2), O(2)eC(2)eC(3): 104.69(19), C(4)eC(3)eC(7): 130.4(2), C(4)eC(3)eC(2): 108.1(2), C(7)eC(3)eC(2): 121.5(2), C(3)eC(4)eC(1):
109.7(2), O(3)eC(5)eC(6): 108.2(2).

2690
P. Mathur et al. / Journal of Organometallic Chemistry 695 (2010) 2687e2694
Scheme 2. Mechanism for the formation of a,b-vinylester.
by direct methods (SHELXS) and refined by full-matrix least squares
against Fo2 using SHELXL-97 software [31]. Non-hydrogen atoms were
refined with anisotropic thermal parameters. All hydrogen atoms
were geometrically fixed and allowed to refine using a riding model.
Fig. 3. ORTEP diagram of 3-ferrocenyl-4-isopropoxy-2-butenolide (17) with 50% prob-
ability ellipsoids. Selected bond length (Å) and bond angles (deg): O(1)eC(1) ¼ 1.211
(3), O(2)eC(1) ¼ 1.377(4), O(2)eC(4) ¼ 1.456(3), O(3)eC(4) ¼ 1.386(3), O(3)eC(5)
¼ 1.460(3), C(1)eC(2) ¼ 1.468(4), C(2)eC(3) ¼ 1.342(4), C(3)eC(8) ¼ 1.455(4), C(3)eC
(4) ¼ 1.517(4), C(8)eC(9) ¼ 1.445(4), C(8)eC(12) ¼ 1.455(4); C(1)eO(2)eC(4) ¼ 109.1
(2), C(4)eO(3)eC(5) ¼ 114.3(2), O(1)eC(1)eO(2) ¼ 120.7(3), O(1)eC(1)eC(2) ¼ 130.9
(3), O(2)eC(1)eC(2) ¼ 108.4(2), C(3)eC(2)eC(1) ¼ 109.5(3), C(2)eC(3)eC(8) ¼ 129.8
(3), C(2)eC(3)eC(4) ¼ 108.3(2), C(8)eC(3)eC(4) ¼ 121.8(2), O(3)eC(4)eO(2) ¼ 109.9
(2), O(3)eC(4)eC(3) ¼ 110.6(2), O(2)eC(4)eC(3) ¼ 104.6(2), C(9)eC(8)eC(12) ¼ 107.1
(2), C(9)eC(8)eC(3) ¼ 126.7(3), C(12)eC(8)eC(3) ¼ 126.2(3).
4.3. General procedure for ironpentacarbonyl catalyzed photolysis
of terminal acetylene, CO and alcohols
To a 60 mL alcoholic solution (methanol, ethanol or isopropanol)
of different terminal acetylene (7.5 mmol), Fe(CO)5 (0.1 mL,
0.1 mmol) was added. This reaction mixture was photolysed for
30 min to 3 h at 0 ꢂC in a photochemical vessel with continuous
bubbling of CO. After removal of volatiles, the residue was subjected
to chromatographic work up. Ethyl acetate/hexane (5:95 v/v)
solvent mixture eluted the orange red (ferrocenyl substituted
vinylesters) or light yellow band (remaining products). Further
elution with (10:90 v/v) solvent mixture yielded the dark red band
of the ferrocenyl substituted lactone or a light yellow band of the
other organic derivatives of lactones.
slow evaporation of n-hexane and dichloromethane solution at
10 ꢂCe15 ꢂC, and X-ray crystallographic data were collected (Table 2).
Oxford Diffraction X calibur-S, CCD system equipped with area
detector was used for the cell determination and intensity data
collection for compounds 1, 16, 17 and 20. Monochromatic Mo K
radiation (0.71359 Å) was used for the measurements. Absorption
corrections using multi -scans were applied. Structures were solved
a
4.3.1. Methyl-3-ferrocenyl-2-propenoate (1)
Yield: 582 mg (37%) as an orange red solid. 1H NMR (CDCl3,
j
400 MHz, 298 K)
J ¼ 15.9 Hz, 1H, FceCH]CHe), 3.70 (s, 3H, eCH3), 4.11 (s, 5H,
C5H5e), 4.39e4.48 (m, 4H, C5H4e). 13C NMR (CDCl3)
167.7 (CO),
d
7.51 (d, J ¼ 15.9 Hz, 1H, FceCH]CHe), 6.05 (d,
d
146 (FceCH]CHe), 114.62 (FceCH]CHe), 70.99 (C5H5e), 69.80 e
68.73 (C5H4e), 51.53 (CH3Oe). IR (Hexane, cmꢀ1): 1727, 1635 (vCO);
MS (m/z, ESþ): 271 (M þ H)þ; M.P. 84e86 ꢂC. Anal. Calc. for
C14H14O2Fe: C, 62.21, H, 5.22. Found: C, 62.14; H 5.20.
4.3.2. Ethyl-3-ferrocenyl-2-propenoate (2)
Yield: 362 mg (23%) as an orange red solid. 1H NMR (CDCl3,
400 MHz, 298 K)
d
7.43 (d, J ¼ 15.6, 1H, FceCH]CHe), 5.94 (d,
J ¼ 15.9, 1H, FceCH]CHe), 4.12 (q, J ¼ 7.3, 2H, eOCH2CH3), 1.25(t,
J ¼ 7.0, 3H, eCH3), 4.09 (s, 5H, C5H5e), 4.32e4.42 (m, 4H, C5H4e).
13C NMR (CDCl3)
d 167.27 (CO), 145.6 (FceCH]CHe), 115.03
(FceCH]CHe), 70.83 (C5H5e), 69.69 e 68.61 (C5H4e), 60.19
(eOCH2), 14.42(CH3e). IR (Hexane, cmꢀ1) 1723, 1637 (vCO). MS (m/z,
ESþ): 285 (M þ H)þ. M.P. 65e67 ꢂC. Anal. Calc. for C15H16O2Fe: C,
63.40. H, 5.76. Found: C, 63.26; H, 5.75.
4.3.3. Isopropyl-3-ferrocenyl-2-propenoate (3)
Yield: 126 mg (8%) as an orange red solid. 1H NMR (CDCl3,
Fig. 4. ORTEP diagram of 3-phenyl-4-isopropoxy-2-butenolide (20) with 50% probability
ellipsoids. Selected bond length (Å) and bond angles (deg) : O(1)eC(1) ¼ 1.208(4), O
(2)eC(11) ¼ 1.379(4), O(2)eC(13) ¼ 1.454(4), O(3)eC(1) ¼ 1.357(4), O(3)eC(11) ¼ 1.449
400 MHz, 298 K)
d
7.49 (d, J ¼ 15.6,1H, FceCH]CHe), 5.96 (d,
(3), C(1)eC(2)
¼
1.457(5), C(2)eC(3)
¼
1.323(4), C(3)eC(4)
¼
1.458(4), C(3)eC
(11) ¼ 1.511(5) , C(4)eC(9) ¼ 1.367(4), C(4)eC(5) ¼ 1.396(5); C(11)eO(2)eC(13) ¼ 114.2
(3), C(1)eO(3)eC(11) ¼ 110.1(3), O(1)eC(1)eO(3) ¼ 122.3(3), O(1)eC(1)eC(2) ¼ 130.0
(4), O(3)eC(1)eC(2) ¼ 107.7(3), C(3)eC(2)eC(1) ¼ 110.2(3), C(2)eC(3)eC(4) ¼ 128.6
(3), C(2)eC(3)eC(11) ¼ 108.2(3), C(4)eC(3)eC(11) ¼ 123.2(3), C(9)eC(4)eC(5) ¼ 118.4
(3), C(9)eC(4)eC(3) ¼ 121.8(4), C(5)eC(4)eC(3) ¼ 119.8(3), O(2)eC(11)eO(3) ¼ 109.3
(3), O(2)eC(11)eC(3) ¼ 109.7(3), O(3)eC(11)eC(3) ¼ 103.7(3).
Scheme 3. Mechanism for the formation of alkoxy g-lactone.

P. Mathur et al. / Journal of Organometallic Chemistry 695 (2010) 2687e2694
2691
Table 2
Crystal data and structure refinement parameters for compounds 1, 16, 17 and 20.
1
16
17
20
Empirical formula
Formula weight
Crystal system
Space group
a, Å
C14H14FeO2
270.10
Monoclinic
P 21/c
14.814 (5)
7.579 (3)
10.863 (4)
90
106.96 (3)
90
1166.6 (8)
4
1.538
1.277
560
C16H16FeO3
312.14
Triclinic
C17H18FeO3
326.16
Monoclinic
P 21/n
13.771 (3)
9.4798 (18)
11.840 (2)
C13H14O3
218.24
Monoclinic
P 21/c
6.0897 (17)
22.819 (8)
8.704 (2)
90
96.29 (3)
90
1202.3 (6)
4
1.206
0.085
464
P ꢀ 1
9.9547 (14)
b, Å
c, Å
10.0955 (12)
13.2895 (15)
90
90
a
b
g
deg
deg
deg
90
108.773 (18)
90
1463.5 (5)
90
V, Å3
1335.6 (3)
4
1.552
1.133
Z
4
Dcalcd, mg mꢀ3
Abs coeff, mmꢀ1
F(000)
1.480
1.037
680
648
Cryst size, mm
0.34 ꢁ 0.32 ꢁ 0.28
3.33 to 24.99
ꢀ17 ꢃ h ꢃ 17
ꢀ6 ꢃ k ꢃ 9
0.28 ꢁ 0.23 ꢁ 0.19
3.07 to 25.00
ꢀ11 ꢃ h ꢃ 11
ꢀ12 ꢃ k ꢃ 5
ꢀ15 ꢃ l ꢃ 14
5833/2331 [R(int) ¼ 0.0268]
2331/0/182
0.34 ꢁ 0.30 ꢁ 0.26
3.13 to 30.00
ꢀ19 ꢃ h ꢃ 19
ꢀ13 ꢃ k ꢃ 12
ꢀ16 ꢃ l ꢃ 15
12981/4250 [R(int) ¼ 0.1140]
4250/0/200
1.040
0.32 ꢁ 0.28 ꢁ 0.15
3.37 to 25.00
ꢀ7 ꢃ h ꢃ 7
ꢀ27 ꢃ k ꢃ 27
ꢀ10 ꢃ l ꢃ 10
q
range, deg
Index ranges
ꢀ10 ꢃ l ꢃ 12
6039/2051 [R(int) ¼ 0.0705]
2051/0/164
Reflections collected/unique
Data/restraints/parameters
Goodness-of-fit on F2
9885/2116 [R(int) ¼ 0.1052]
2116/0/147
0.924
0.932
0.836
Final R indices [I > 2
R indices (all data)
s
(I)]
R1 ¼ 0.0526, wR2 ¼ 0.1201
R1 ¼ 0.0772, wR2 ¼ 0.1309
0.578 and ꢀ0.692
R1 ¼ 0.0255, wR2 ¼ 0.0623
R1 ¼ 0.0273, wR2 ¼ 0.0630
0.348 and ꢀ0.375
R1 ¼ 0.0463, wR2 ¼ 0.1154
R1 ¼ 0.0777, wR2 ¼ 0.1542
0.949 and ꢀ0.769
R1 ¼ 0.0592, wR2 ¼ 0.1269
R1 ¼ 0.1682, wR2 ¼ 0.1593
0.161 and ꢀ0.157
Largest diff peak and hole, eÅꢀ3
J ¼ 15.6, 1H, FceCH]CHe), 5.01 (septet, J ¼ 6.3, 1H, eOCH(CH3)2),
1.17 (d, J ¼ 6.4, 6H, CH3), 4.06 (s, 5H, C5H5), 4.31e4.41 (m, 4H, C5H4).
9H, CH3e). 13C NMR (CDCl3)
d 170.12 (CO), 160.31 ((CH3)3SieCH]
CHe), 127.39 ((CH3)3SieCH]CHe), 59.5 (eOCH3), ꢀ1.08 (CH3). IR
13C NMR (CDCl3)
d 166.95 (CO), 145.44 (FceCH]CHe), 115.76
(Hexane, cmꢀ1) 1724, 1638 (vCO); MS (m/z, ESþ): 159.29 (M þ H)þ.
(FceCH]CHe), 70.89 (C5H5e), 69.80
e 68.71(C5H4e), 14.38
(CH3e). IR (Hexane, cmꢀ1) 1713, 1634 (vCO); MS (m/z, ESþ): 298
(M)þ. M.P. 72e74 ꢂC. Anal. Calc. for C16H18O2Fe: C, 64.45; H, 6.09.
Found: C, 64.51; H, 6.14.
4.3.8. Ethyl-3-trimethylsilyl-2-propanoate (8)
Yield: 228 mg (31%) as a light yellow liquid. 1H NMR (CDCl3,
400 MHz, CDCl3, 298 K)
d
5.89 (d, J ¼ 5.2 Hz,1H, (CH3)3SieCH]CHe),
3.44 (d, J ¼ 5.2 Hz, 1H, (CH3)3SieCH]CHe), 4.15 (q, J ¼ 7.1 Hz, 2H,
4.3.4. Methyl-3-phenyl-2-propenoate (4)
eOCH2e), 1.16 (t, J ¼ 7.0 Hz, 3H, CH3eCH2e), 0.36 (s, 9H, CH3e). 13
C
Yield: 260 mg (34%) as a light yellow liquid. 1H NMR (CDCl3,
NMR (CDCl3) d 169.14 (CO), 118.02 ((CH3)3SieCH]CHe), 89.82
400 MHz, 298 K)
J ¼ 3.4 Hz, 1H, PheCH]CHe), 3.42 (s, 3H, eOCH3), 7.21e7.43 (m,
5H, C6H5e). 13C NMR (CDCl3)
167.46 (CO), 144.99 (PheCH]CHe),
d
7.71 (d, J ¼ 3.4 Hz, 1H, PheCH]CHe), 6.45 (d,
((CH3)3SieCH]CHe), 65.70 (eOCH2e)15.07 (CH3CH2e),1.60 (CH3e).
IR (Hexane, cmꢀ1) 1754, 1649 (vCO); MS (m/z, ESþ): 172.14 (M)þ.
d
119.61 (PheCH]CHe), 134.58 e 128.19 (C6H5e), 51.70 (eOCH3). IR
4.3.9. Isopropyl-3-trimethylsilyl-2-propanoate (9)
(Hexane, cmꢀ1) 1730, 1641 (vCO); MS (m/z, ESþ): 163.0 (M þ H)þ.
Yield: 125 mg (17%) as a light yellow liquid. 1H NMR (CDCl3,
400 MHz, 298 K)
d
5.87 (d, J ¼ 7.8 Hz, 1H, (CH3)3SieCH]CHe), 4.22 (d,
4.3.5. Ethyl-3-phenyl-2-propenoate (5)
6.1 Hz,1H, (CH3)3SieCH]CHe), 4.36 (septet, J ¼ 6.1 Hz,1H, eOCHe),
Yield: 222 mg (29%) as a light yellow liquid. 1H NMR (CDCl3,
1.28 (d, J ¼ 5.2 Hz, 6H, eOCH(CH3)2), 0.23 (s, 9H, CH3e). 13C NMR
400 MHz, 298 K)
d
7.59 (d, J ¼ 16.2 Hz, 1H, PheCH]CHe), 6.34 (d,
(CDCl3)
d
184.56 (CO) 124.81 ((CH3)3SieCH]CHe), 97.74
J ¼ 16.2 Hz,1H, PheCH]CHe), 4.16 (q, J ¼ 7.7 Hz, 2H, eOCH2e),1.28
((CH3)3SieCH]CHe), 71.38 (eOCHe), 21.19 (eOCH(CH3)2), ꢀ0.70
(t, J ¼ 7.0 Hz, 3H, CH3e), 7.31e7.46 (m, 5H, C6H5e). 13C NMR (CDCl3)
(CH3). IR(Hexane, cmꢀ1)1744,1632 (vCO);MS(m/z, ESþ):186.19 (M)þ.
d
167.17 (CO), 144.75 (PheCH]CHe), 118.43 (PheCH]CHe), 134.63
e 126.62 (C6H5e), 60.66 (eOCH2e), 14.48 (CH3e). IR (Hexane,
4.3.10. Methyl-2-heptenoate (10)
cmꢀ1) 1724, 1641 (vCO); MS (m/z, ESþ): 176.21(M)þ.
Yield: 178 mg (29%) as a light yellow liquid. 1H NMR (CDCl3,
400 MHz, 298 K)
J ¼ 3.1 Hz, 1H, C4H9eCH]CHe), 3.80 (s, 3H,eOCH3), 0.90e2.17 (m,
9H, C4H9e).13C NMR (CDCl3)
169.01 (CO),138.41 (C4H9eCH]CHe),
d
7.70 (m, J ¼ 3.5 Hz, 1H, C4H9eCH]CHe), 7.52 (d,
4.3.6. Isopropyl-3-phenyl-2-propenoate (6)
Yield: 176 mg (23%) as a light yellow liquid. 1H NMR (CDCl3,
d
400 MHz, 298 K)
d
7.68 (d, J ¼ 16.2 Hz, 1H, PheCH]CHe), 6.32 (d,
121 67 (C4H9eCH]CHe), 53.91(eOCH3), 33.41 e 14.21(C4H9e). IR
J ¼ 16.2 Hz, 1H, PheCH]CHe), 5.10 (septet, J ¼ 6.3 Hz, 1H, eOCHe),
(Hexane, cmꢀ1) 1739, 1654 (vCO); MS (m/z, ESþ): 141.94 (M)þ.
1.20 (d, J ¼ 6.4 Hz, 6H, eCH3), 7.34e7.51(m, 5H, C6H5e). 13C NMR
(CDCl3)
d
166.59 (CO), 144.42 (PheCH]CHe), 118.96 (PheCH]
4.3.11. Ethyl-2-heptenoate (11)
CHe), 134.7 e 128.13 (C6H5e), 67.87(eOCHe), 22.05 (CH3). IR
Yield: 129 mg (21%) as a light yellow liquid. 1H NMR (CDCl3,
(Hexane, cmꢀ1) 1719, 1640 (vCO); MS (m/z, ESþ): 191.13 (M þ H)þ.
400 MHz, 298 K)
(d, J ¼ 15.8 Hz, 1H, C4H9eCH]CHe), 4.41 (q, J ¼ 6.4 Hz, 2H,
eOCH2CH3), 0.91e2.29 (m, 9H, C4H9e). 13C NMR (CDCl3)
169.13
d
6.95 (m, J ¼ 13.4 Hz, 1H, C4H9eCH]CHe), 6.63
4.3.7. Methyl-3-trimethylsilyl-2-propanoate (7)
d
Yield: 191 mg (26%) as a light yellow liquid. 1H NMR (CDCl3,
(CO), 161.18 (C4H9eCH]CHe), 121.17 (C4H9eCH]CHe), 58.41
(eOCH2CH3), 32.04 e 14.38 (C4H9). IR (Hexane, cmꢀ1) 1734, 1654
(vCO); MS (m/z, ESþ): 155.10 (M þ H)þ.
400 MHz, 298 K)
d
5.90 (d, J ¼ 5.1 Hz, 1H, (CH3)3SieCH]CHe), 3.44
(d, J ¼ 5.1 Hz, 1H, (CH3)3SieCH]CHe), 3.56 (s, 3H, eOCH3), 1.24 (s,

2692
P. Mathur et al. / Journal of Organometallic Chemistry 695 (2010) 2687e2694
4.3.12. Isopropyl-2-heptenoate (12)
CHe), 102.51 (eCH(OCH3)), 135.71 e 128.21 (C6H5e), 53.47
(eOCH3). IR (Hexane, cmꢀ1) 1739, 1656 (vCO); MS (m/z, ESþ):
190.09 (M)þ.
Yield: 73 mg (12%) as a light yellow liquid. 1H NMR (CDCl3,
400 MHz, 298 K)
J ¼ 14.1, Hz, 1H,, C4H9eCH]CHe), 2.19(m, 2H, eCH2e), 1.31 (m, 2H,
eCH2e), 1.17 (t, 3H, CH3e). 13C NMR (CDCl3)
165.21 (CO), 137.89
d 6.91 (m, 1H, C4H9eCH]CHe), 5.82 (d,
d
4.3.19. 3-Phenyl-4-ethoxy-2-butenolide (19)
(C4H9eCH]CHe), 125.41 (C4H9eCH]CHe), 68.91 (eOCH(CH3)2),
32. 44 e 13.84 (C4H9e). IR (Hexane, cmꢀ1) 1729, 1633 (vCO); MS
(m/z, ESþ): 170.15 (M)þ.
Yield: 482 mg (63%) as a yellow liquid. 1H NMR (CDCl3, 400 MHz,
298 K) d 6.29 (s, 1H, eCH(OCH2CH3)), 6.42 (s, 1H, PheC]CHe), 4.01
(q, J ¼ 6.1 Hz, 2H, eOCH2CH3), 7.21e7.73 (m, 5H, C6H5e), 1.20 (d,
J ¼ 6.1 Hz, 3H, eOCH2CH3). 13C NMR (CDCl3)
d 167.09 (CO), 151.14
4.3.13. Methyl-3-cyclohexyl-2-propenoate (13)
(PheC]CHe), 140.02 (PheC]CHe), 128.61 e 126.85 (C6H5e),
61.38 (eOCH2CH3), 14.01 (eOCH2CH3). IR (Hexane, cmꢀ1) 1743,
1629 (vCO); MS (m/z, ESþ): 204.81 (M)þ.
Yield: 259 mg (32%) as a light yellow liquid. 1H NMR (CDCl3,
400 MHz, 298 K)
J ¼ 14.2 Hz, 1H, C6H11CH]CHe), 3.72 (s, 3H, eOCH3), 2.12 (m, 1H,
C6H11), 0.86e1.54 (m, 10H, C6H11). 13C NMR (CDCl3)
167.91 (CO),
d
6.89 (q, J ¼ 6.9 Hz, 1H, C6H11CH]CHe), 5.78 (d,
d
4.3.20. 3-Phenyl-4-isopropoxy-2-butenolide (20)
152.20 (C6H11CH]CHe), 121.47 (C6H11CH]CHe), 51.97 (eOCH3),
39.94 e 25.89 (C6H11e). IR (Hexane, cmꢀ1) 1736, 1620 (vCO); MS
(m/z, ESþ): 169.11 (M þ H)þ.
Yield: 543 mg (71%) as a yellow liquid. 1H NMR (CDCl3, 400 MHz,
298 K)
4.20 (septet, J ¼ 7.0 Hz,1H, eCH(OCH(CH3)2)),1.30 (d, J ¼ 6.2 Hz, 6H,
e(OCH(CH3)2)), 7.20e7.6 (m, 5H, C6H5e). 13C NMR (CDCl3)
170.99
d 6.34 (s, 1H, eCH(OCH(CH3)2)), 6.43 (s, 1H, PheC]CHe),
d
4.3.14. Isopropyl-3-cyclohexyl-2-propenoate (14)
(CO), 161.62(PheC]CHe), 115.92 (PheC]CHe), 101.48 (eCH(OCH
(CH3)2), 133.82 e 127.79 (C6H5e), 22.14 (eOCH(CH3)2). IR (Hexane,
cmꢀ1): 1750, 1625 (vCO); MS (m/z, ESþ): 219.14 (M þ H)þ.
Yield: 121 mg (15%) as a light yellow liquid. 1H NMR (CDCl3,
400 MHz, 298 K)
J ¼ 15.8 Hz 1H, C6H11CH]CHe), 5.01 (septet, J ¼ 6.4 Hz, 1H, eOCH
(CH3)2), 1.24 (d, J ¼ 5.8 Hz, 6H, eOCH(CH3)2), 2.02 (m, 1H, C6H11),
d
6.86 (q, J ¼ 6.7 Hz, 1H, C6H11CH]CHe), 5.70 (d,
4.3.21. 3-Trimethylsilyl-4-methoxy-2-butenolide (21)
0.96e1.54 (m, 10H, C6H11e). 13C NMR (CDCl3)
d
168.82 (CO), 154.08
Yield: 523 mg (71%) as a light yellow liquid. 1H NMR (CDCl3,
(C6H11CH]CHe), 119.46 (C6H11CH]CHe), 67.97 (eOCH(CH3)2),
40.49 e 21.94 (C6H11e). IR (Hexane, cmꢀ1) 1707, 1580 (vCO); MS
(m/z, ESþ): 197.18 (M þ H)þ.
400 MHz, 298 K)
(CH3)3SiC]CHe), 3.55 (s, 3H, eOCH3), 0.24 (s, 9H, eSi(CH3)3). 13
NMR (CDCl3) 170.12 (CO), 160.31 ((CH3)3SiC]CHe), 127.39
d 5.30 (s, 1H, eCH(eOCH3)), 5.52 (s, 1H,
C
d
((CH3)3SiC]CHe), 89.5 (eCH(eOCH3)), ꢀ1.86 (eSi(CH3)3). IR
4.3.15. 3-Ferrocenyl-4-methoxy-2-butenolide (15)
(Hexane, cmꢀ1) 1748, 1663 (vCO); MS (m/z, ESþ): 185.01 (M ꢀ H)þ.
Yield: 945 mg (60%) as a dark red solid. 1H NMR (CDCl3,
400 MHz, 298 K)
3.59 (s, 3H, eOCH3), 4.18 (s, 5H, C5H5e), 4.53e4.80 (m, 4H, C5H4e).
13C NMR (CDCl3)
171.24 (CO), 165.08 (FceC]CHe), 111.36 (FceC]
CHe), 103.20 (eCH(OCH3)), 71.49 (C5H5e), 68.65 e 68.18 (C5H4e),
55.81 (eOCH3). IR (Hexane, cmꢀ1) 1793, 1619 (vCO); MS (m/z, ESþ):
299 (M þ H)þ. M.P. 96e98 ꢂC. Anal. Calc. for C15H14O3Fe: C, 60.43; H,
4.73. Found: C, 60.39; H, 4.81.
d
6.18 (s,1H, FceC]CHe), 6.16 (s,1H, eCH(OCH3)),
4.3.22. 3-Trimethylsilyl-4-ethoxy-2-butenolide (22)
Yield: 493 mg (67%) as a light yellow liquid. 1H NMR (CDCl3,
d
400 MHz, 298 K)
(eOCH2CH3)), 4.13 (q, J ¼ 5.0 Hz, 2H,, eOCH2CH3), 1.20 (t, J ¼ 7.0 Hz,
3H, eOCH2CH3)). 13C NMR (CDCl3)
173.44 (CO), 130.80
d 5.67 (s, 1H, (CH3)3SiC]CHe), 5.30 (s, 1H, eCH
d
((CH3)3SiC]CHe), 96.47 (eCH(OCHCH3), 64.35 (eOCH2CH3), 14.88
(eOCH2CH3), ꢀ0.56(eSi(CH3)3). IR (Hexane, cmꢀ1) 1754, 1652
(vCO); MS (m/z, ESþ): 200.17 (M)þ.
4.3.16. 3-Ferrocenyl-4-ethoxy-2-butenolide (16)
Yield: 1165 mg (74 %) as a dark red solid. 1H NMR (CDCl3,
4.3.23. 3-Trimethylsilyl-4-(2-propoxy)-2-butenolide (23)
400 MHz, 298 K)
d
5.96 (s, 1H, eCH(OCH2CH3)), 6.03 (s, 1H, FceC]
Yield: 604 mg (82%) as a light yellow liquid. 1H NMR (CDCl3,
CHe), 3.79 (m, 2H, eOCH2CH3), 1.34 (t, J ¼ 7.4 Hz, 3H, (eOCH2CH3)),
400 MHz, 298 K) d 5.71 (s, 1H, (CH3)3SiC]CHe), 5.65 (s, 1H, eCH
4.18 (s, 5H, C5H5e), 4.53e4.68 (m, 4H, C5H4e). 13C NMR (CDCl3)
(eOCH(CH3)2)), 4.21 (Septet, J ¼ 6.1 Hz, 1H, eOCH(CH3)2), 1.28 (d,
d
171.53 (CO), 165.42 (FceC]CHe), 111.5 (FceC]CHe), 102.66
J ¼ 5.2 Hz, 6H, eOCH(CH3)2), 0.26 (s, 9H, eSi(CH3)3). 13C NMR
(eCH(eOCH2CH3)), 71.91 (C5H5e), 69.8 e 65.2 (C5H4e), 50.99
(eOCH2CH3), 15.37 (eOCH2CH3), . IR (Hexane, cmꢀ1) 1793, 1625
(vCO); MS (m/z, ESþ): 313 (M þ H)þ. M.P. 98e100 ꢂC. Anal. Calc. for
C16H16O3Fe: C, 61.34; H, 5.11. Found: C, 61.30; H, 5.09.
(CDCl3)
d
170.31 (CO), 162.26 ((CH3)3SiC]CHe), 130.68
((CH3)3SiC]CHe), 95.73 (eCH(eOCH(CH3)2)), 68.16 (eOCH(CH3)2),
23.56 (eOCH(CH3)2), ꢀ0.78 (eSi(CH3)3). IR (Hexane, cmꢀ1) 1772,
1600 (vCO); MS (m/z, ESþ): 214.19 (M)þ.
4.3.17. 3-Ferrocenyl-4-isopropoxy-2-butenolide (17)
4.3.24. 3-Butyl-4-methoxy-2-butenolide (24)
Yield: 1386 mg (88%) as a dark red solid. 1H NMR (CDCl3,
Yield: 320 mg (52%) as a light yellow liquid. 1H NMR (CDCl3,
400 MHz, 298 K)
d
5.96 (s,1H, eCH(OCH(CH3)2)), 6.02 (s,1H, FceC]
400 MHz, 298 K)
(OCH3)), 3.62 (s, 3H, eOCH3), 2.24 (m, 2H, C4H9e), 0.95e2.24 (m,
7H, C4H9e). 13C NMR (CDCl3)
173.61 (CO), 162.43 (C4H9C]CHe),
d 5.67 (s, 1H, C4H9C]CHe), 6.49 (s, 1H, eCH
CHe), 4.18 (m, 1H, eCH(OCH(CH3)2)), 1.2 (d, J ¼ 6.2 Hz, 6H, eOCH
(CH3)2), 4.18 (s, 5H, C5H5e), 4.52e4.66 (m, 4H, C5H4e). 13C NMR
d
(CDCl3)
d
171.68 (CO), 165.60 (FceC]CHe), 111.40 (FceC]CHe),
121.37 (C4H9C]CHe), 51.49 9 (eOCH3), 34.55e15.11 (C4H9e). IR
101.39 (eCH(eOCH(CH3)2)), 71.76 (C5H5e), 68.56 e 68.52 (C5H4e),
22.07 (CH3e). IR (Hexane, cmꢀ1) 1796, 1630 (vCO); MS (m/z, ESþ):
327 (M þ H)þ. M.P. 90e94 ꢂC. Anal. Calc. for C17H18O3Fe: C, 62.57; H,
5.52. Found, C, 62.49; H, 5.54.
(Hexane, cmꢀ1) 1748, 1654 (vCO); MS (m/z, ESþ): 171.10 (M þ H)þ.
4.3.25. 3-Butyl-4-ethoxy-2-butenolide (25)
Yield: 468 mg (76%) as a light yellow liquid. 1H NMR (CDCl3,
400 MHz, 298 K)
d 5.70 (s, 1H, C4H9C]CHe), 5.85 (s, 1H, eCH
4.3.18. 3-Phenyl-4-methoxy-2-butenolide (18)
(OCH2CH3)), 3.96 (q, J ¼ 2.8 Hz, 2H, eOCH2CH3), 1.10- 2.12 (m, 9H,
Yield: 451 mg (59%) as a light yellow liquid. 1H NMR (CDCl3,
C4H9e), 1.11 (t, J ¼ 7.0 Hz, 3H, eOCH2CH3). 13C NMR (CDCl3)
d 168.27
400 MHz, 298 K)
(OCH3)), 3.58 (s, 3H, eOCH3), 7.26e7.74 (m, 5H, C6H5e). 13C
NMR (CDCl3) 169.2 (CO), 159.83 (PheC]CHe), 114.93 (PheC]
d
6.43 (s, 1H, PheC]CHe), 6.25 (s, 1H, eCH
(CO), 162.31 (C4H9C]CHe), 117.91 (C4H9C]CHe), 103.70 (eCH
(OCH2CH3)), 61.01 (eOCH2CH3), 30.04 e 9.81 (C4H9e). IR (Hexane,
cmꢀ1) 1799, 1638 (vCO); MS (m/z, ESþ): 185.11 (M þ H)þ.
d

P. Mathur et al. / Journal of Organometallic Chemistry 695 (2010) 2687e2694
2693
[6] (a) R.F. Heck, J.P. Nolley, J. Org. Chem. 37 (1972) 2320;
4.3.26. 3-Butyl-4-(2-propoxy)-2-butenolide (26)
(b) V. Polshettiwar, P. Hesemann, J.E. Moreau, Tetrahedron Lett. 48 (2007)
5363;
(c) M. Rosol, A. Moyano, J. Organomet. Chem. 690 (2005) 2291.
[7] (a) A. Kashara, T. Lzumi, G. Saito, M. Yodono, R.-I. Saito, Y. Goto, Bull. Chem.
Soc. Jpn. 45 (1972) 895;
(b) R.E. Fish, J. Rosenblum, J. Org. Chem. 30 (1965) 1253.
[8] (a) S. Shirakami, T. Itoh, Tetrahedron: Asymmetry 11 (2000) 2823;
(b) W. Zhang, Y. Yoneda, T. Kida, Y. Nakatsuji, I. Ikeda, J. Organomet. Chem.
574 (1999) 19;
(c) P. Debroy, D. Naskar, S. Roy, Inorg. Chim. Acta 359 (2006) 1215.
[9] (a) R. Asano, I. Moritani, A. Sonoda, Y. Fujiwara, S. Teranishi, Chem. Soc.
Organic Chem. (C) 3691 (1971);
Yield: 529 mg (86%) as a light yellow liquid. 1H NMR (CDCl3,
400 MHz, 298 K) d 5.98 (s, 1H, C4H9C]CHe), 6.94 (s, 1H, eCH(OCH
(CH3)2)), 5.0 (septet, J ¼ 6.3 Hz, 1H, eCH(OCH(CH3)2)), 0.88e2.23
(m, 9H, C4H9e), 1.09 (d, J ¼ 6.1 Hz, 6H, eOCH(CH3)2). 13C NMR
(CDCl3)
d 171.52 (CO), 164.05 (C4H9C]CHe), 119.67 (C4H9C]CHe),
104.09 (eCH(OCH(CH3)2), 68.71 (eOCH(CH3)2), 31.45 e 14.37
((eCH3)2). IR (Hexane, cmꢀ1) 1776, 1640 (vCO); MS (m/z, ESþ):
197.12 (M ꢀ H)þ.
(b) M. Tani, S. Sakaguchi, Y. Ishii, J. Org. Chem. 69 (2004) 1221;
(c) C. Bianchini, H.M. Lee, G. Mantovani, A. Meli, New J. Chem. 26 (2002) 387.
[10] (a) Y. Oikaw, T. Yoshioka, O. Yonemitsu, Tetrahedron Lett. 23 (1982) 889;
(b) M. Aslam, W.F. Stansbury, R.J. Reiter, D.R. Larkin, J. Org. Chem. 62 (1997)
1550;
4.3.27. 3-Cyclohexyl-4-methoxy-2-butenolide (27)
Yield: 486 mg (60%) as a light yellow liquid. 1H NMR (CDCl3,
400 MHz, 298 K)
(OCH3)), 3.72 (s, 3H, eOCH3), 2.05 (m, 1H, C6H11e), 1.12e1.77 (m, 10
H, C6H11). 13C NMR (CDCl3)
169.01 (CO), 160.27 (C6H11C]CHe),
d 6.39 (s, 1H, C6H11C]CHe), 6.47 (s, 1H, eCH
(c) T. Iliefski, S. Li, K. Lundquist, Tetrahedron Lett. 39 (1998) 2413;
(d) R. Gopinath, B.K. Patel, Org. Lett. 2 (2000) 577;
d
128.40 (C6H11C]CHe), 121.40 (eCH(OCH3)), 49.86 (eOCH3), 40.51
e 26.76 (C6H11). IR (Hexane, cmꢀ1) 1737, 1654(vCO); MS (m/z, ESþ):
198.10 (M þ 2H)þ.
(e) A. Stadler, C.O. Kappe, Tetrahedron 57 (2001) 3915;
(f) S.F. Jonathan, K. Hisashi, M.P.G. Gerard, J.K.T. Richard, Synlett 1293 (2002);
(g) S. Crosignani, P.D. White, R. Steinauer, B. Linclau, Org. Lett. 5 (2003) 853;
(h) R. Gopinath, B. Barkakaty, B. Talukdar, B.K. Patel, J. Org. Chem. 68 (2003) 2944;
(i) H.M.S. Kumar, M.S. Kumar, S. Joyasawal, J.S. Yadav, Tetrahedron Lett. 44
(2003) 4287;
4.3.28. 3-Cyclohexyl-4-(2-propoxy)-2-butenolide (28)
Yield: 640 mg (79%) as a light yellow liquid. 1H NMR (CDCl3,
(j) A.R. Bressette, L.C. Glover IV, Synlett 738 (2004);
(k) G. Deng, B. Xu, C. Liu, Tetrahedron 61 (2005) 5818;
(l) V. Pathania, A. Sharma, A.K. Sinha, Helv. Chim. Acta 88 (2005) 811;
(m) B. List, A. Doehring, M.T.H. Fonseca, K. Wobser, H.V. Thienen, R.R. Torres,
P.L. Galilea, Adv. Synth. Catal 347 (2005) 1558.
400 MHz, 298 K)
d 7.10 (s, 1H, eCH(OCH(CH3)2)), 6.36 (s, 1H,
C6H11C]CHe), 5.0 (septet, J ¼ 6.4 Hz, 1H, eOCH(CH3)2), 1.25 (d,
J ¼ 3.0 Hz, 6H, eOCH(CH3)2), 2.17 (m, 1H, C6H11e), 1.03e1.81 (m,
[11] P.L. Triozze, J. Ailabouni, J.J. Rinehart, D.T. Witiak, Int. J. Pharmacol. 15 (1993) 47.
[12] X.P. Fang, J.E. Anderson, D.L. Smith, J.L. McLaughlin, K.V. Wood, J. Nat. Prod.
55 (1992) 1655.
[13] H. Mori, N. Yoshimi, S. Sugie, T. Tanaka, Y. Morishita, G. Jinlong, Y. Tamai,
M. Torihara, J. Yamahara, Cancer Lett. 66 (1992) 93.
[14] M. Pour, M. Spulak, V. Buchta, P. Kubanova, M. Voprsalova, V. Wsol, H. Fakova,
P. Koudelka, H. Pourova, R. Schiller, J. Med. Chem. 44 (2001) 2701.
[15] (a) X.-P. Fang, J.E. Anderson, C.-J. Chang, J.L. McLaughlin, Tetrahedron
47 (1991) 9751;
10H, C6H11e). 13C NMR (CDCl3)
d 171. 09 (CO), 152.45 (C6H11C]
CHe), 121.98 45 (C6H11C]CHe), 110.48 (eCH(OCH(CH3)2)), 76.88
(eOCH(CH3)2), 39.10 e 26.38 (C6H11e). IR (Hexane, cmꢀ1) 1720,
1654 (vCO); MS (m/z, ESþ): 225.01 (M þ H)þ.
Acknowledgements
(b) J.K. Ruprecht, Y.H. Hui, J.L. Mclaughlin, J. Nat. Prod. 53 (1990) 237.
[16] (a) B.E. Roggo, P. Hug, S. Moss, F. Raschorf, H.H. Peter, J. Antibiot. 47 (1994)
143;
R. K Joshi and A.K. Singh thank CSIR, New Delhi; Badrinath Jha
thanks UGC, New Delhi for providing research fellowship. P. Mathur
thanks DST, New Delhi for J. C. Bose Fellowship.
(b) B.E. Roggo, F. Petersen, R. Delmendo, H.B. Jenny, H.H. Peter, J.J. Roesel,
J. Antibiot. 47 (1994) 136.
[17] C. Imrie, C. Loubser, P. Engelbrecht, C.W. McCleland, Y. Zheng, J. Organomet.
Chem. 665 (2003) 48.
[18] (a) H. Korri-Youssoufi, B. Makrouf, Anal. Chim. Acta 469 (2002) 85;
(b) J. Rolfes, J.T. Andersson, Anal. Chem. 73 (2001) 3073;
(c) L. Busetto, M.C. Cassani, V.G. Albano, P. Sabatino, Organometallics 21
(2002) 1849;
Appendix. Supplementary data
Crystallographic data for the structural analysis have been
deposited with the Cambridge. Crystallographic Data Centre, CCDC
no. 736357, 736356, 736354 and 736355 for compounds 1, 16e17
and 20 respectively. Copies of this information may be obtained
free of charge from The Director, CCDC, 12 Union Road, Cambridge
CB2 1EZ, UK (Fax: þ44-1223-336033; e-mail: deposit@ccdc.cam.ac.
uk or http://www.ccdc.cam.ac.uk). Supplementary data associated
with this article can be found in the online version, at doi:10.1016/j.
jorganchem.2010.08.036.
(d) A.A. Nazarov, C.G. Hartinger, V.B. Arion, G. Giester, B.K. Keppler, Tetrahe-
dron 58 (2002) 8489;
(e) M. Buda, J.-C. Moutet, E. Saint-Aman, A. De Cian, J. Fischer, R. Ziessel, Inorg.
Chem. 37 (1998) 4146.
[19] (a) P. Debory, M. Banerjee, M. Prasad, S.P. Moulik, S. Roy, Org. Lett. 7 (2005) 403;
(b) D. Naskar, S.K. Das, L. Giribabu, B.G. Maiya, S. Roy, Organometallics 19 (2000)
1464.
[20] (a) E. Peris, Cood. Chem. Rev. 248 (2004) 279;
(b) A. Togni, T. Hayashi, in: Ferrocene, VSH, New York, 1995, p. 195;
(c) S. Barlow, S.R. Marder, Chem. Commun. 1555 (2000).
[21] (a) C. Bolm, J. Legros, J. Le Paih, L. Zani, Chem. Rev. 104 (2004) 6217;
(b) B. Plietker (Ed.), Iron Catalysis in Organic Chemistry, WILEY-VCH Verlag
GmbH, Weinheim, 2008;
References
(c) S. Enthaler, K. Junge, M. Beller, Angew. Chem. 120 (2008) 3363 Angew.
Chem. Int. Ed. 47 (2008) 3317;
(d) A. Correa, O.G. Mancheno, C. Bolm, Chem. Soc. Rev. 37 (2008) 1108;
(e) B.D. Sherry, A. Fürstner, Acc. Chem. Res. 41 (2008) 1500;
(f) W.M. Czaplik, M. Mayer, J. Cvengros, A.J.V. Wangelin, ChemSusChem. 2
(2009) 396;
(g) A. Fürstner, Angew. Chem. 121 (2009) 1390 Angew.Chem. Int. Ed. 48
(2009) 1364;
(h) R.M. Bullock, Angew.Chem. 119 (2007) 7504 Angew. Chem. Int. Ed. 46
(2007) 7360;
[1] (a) W. Reppe, German Patent, 855 (1939) 110; (b) J. Tsuji, M. Takahashi,
T. Takahashi, Tetrahedron Lett. 21 (1980) 849;
(c) D. Zargarian, H. Alper, Organometallics 10 (1991) 2914;
(d) R.F. Heck, J. Am. Chem. Soc. 94 (1972) 2712.
[2] (a) J. Tsuji, M. Morikawa, N. Iwamoto, J. Am. Chem. Soc. 86 (1964) 2095;
(b) J. Tsuji, T. Nogi, J. Org. Chem. 31 (1966) 2641.
[3] (a) J. Tsuji, T. Nogi, J. Am. Chem. Soc. 88 (1966) 1289;
(b) J. Tsuji, in: Palladium reagents and Catalysis- Innovations in Organic
synthesis, Wiley, Chichester, 1995.
[4] (a) M. Bassetti, A.D. Annibale, A. Fanfoni, F. Minissi, Org. Lett. 7 (2005) 1805;
(b) D.M. Browne, O. Niyomura, T. Wirth, Org. Lett. 9 (2007) 3169;
(c) D. Tejedor, A. Santos-Exposito, F. Garcia-Tellado, Synlett 1607 (2006);
(d) Y. Liu, F. Song, S. Guo, J. Am. Chem. Soc. 128 (2006) 11332;
(e) S. Ma, F. Yu, Tetrahedron 61 (2006) 9896;
(i) M. Lautens, A. Rudolph, Angew. Chem. 121 (2009) 2694 Angew. Chem. Int.
Ed. 48 (2009) 2656;
(j) S. Gaillard, J.-L. Renaud, ChemSusChem. 1 (2008) 505;
(k) A. Fürstner, K. Majima, R. Martin, H. Krause, E. Kattnig, R. Goddard,
C.W. Lehmann, J. Am. Chem. Soc. 130 (2008) 1992;
(l) J. Norinder, A. Matsumoto, N. Yoshikai, E.J. Nakamura, J. Am. Chem. Soc. 130
(2008) 5858;
(m) J. Wen, J. Zhang, S.-Y. Chen, J. Li, X.-Q. Yu, Angew. Chem. 120 (2008) 9029
Angew. Chem. Int. Ed. 47 (2008) 8897;
(n) Y. Wang, E.A.F. Fordyce, F.Y. Chen, H.W. Lam, Angew. Chem. 120 (2008)
7460 Angew. Chem. Int. Ed. 47 (2008) 7350;
(f) C. Fu, S. Ma, Eur. J. Org. Chem. 3942 (2005);
(g) J. Wu, Q. Zhu, L. Wang, R. Fathi, Z. Yang, J. Org. Chem. 68 (2003) 670;
ꢀ
(h) K. Pomeisl, J. Cejka, J. Kvícala, O. Paleta, Eur. J. Chem. 5917 (2007);
(i) G.M. Lee, M. Parvez, S.N. Weinree, Tetrahedron 44 (1988) 4671;
(j) Y. Shvo, Y. Blum, D. Reshef, J. Orgamomet. Chem. 238 (1982) C79.
[5] T. Joh, H. Nagata, S. Takahashi, Inorg. Chim. Acta 220 (1994) 45.

2694
P. Mathur et al. / Journal of Organometallic Chemistry 695 (2010) 2687e2694
(o) A. Okada, K. Arayama, R. Murayama, T. Ishizuka, K. Hara, N. Hirone, T. Hata,
H. Urabe, Angew. Chem. 120 (2008) 6966 Angew. Chem. Int. Ed. 47 (2008) 6860;
(p) Z. Lu, G. Chai, S. Ma, J. Am. Chem. Soc. 129 (2007) 14546.
(e) M. Periasamy, A. Mukkanti, D.S. Raj, Organometallics 23 (2004) 6323;
(f) M. Periasamy, A. Mukkanti, D.S. Raj, Organometallics 23 (2004) 619.
[24] (a) C. Rameshkumar, M. Periasamy, Synlett 1619 (2000);
(b) M. Periasamy, C. Rameshkumar, A. Mukkati, J. Organomet. Chem. 649
(2002) 209.
[22] (a) S. Enthaler, G. Erre, M.K. Tse, K. Junge, M. Beller, Tetrahedron Lett. 47
(2006) 8095;
(b) S. Enthaler, H. Hagemann, G. Erre, K. Junge, M. Beller, Chem. Asian J. 1
(2006) 598;
[25] (a) P. Mathur, S. Chatterjee, A. Das, G.K. Lahiri, S. Maji, S.M. Mobin, J. Orga-
nomet. Chem. 692 (2007) 1601;
(c) G. Anilkumar, B. Bitterlich, F.G. Gelalcha, M.K. Tse, M. Beller, Chem. Com-
mun. 289 (2007);
(b) P. Mathur, S. Chatterjee, A. Das, S.M. Mobin, J. Organomet. Chem. 692
(2007) 819;
(d) F.G. Gelalcha, B. Bitterlich, G. Anilkumar, M.K. Tse, M. Beller, Angew. Chem.
119 (2007) 7431 Angew. Chem. Int. Ed. 46 (2007) 7293;
(e) F. Shi, M.K. Tse, M.-M. Pohl, A. Brückner, S. Zhang, M. Beller, Angew. Chem.
46 (2007) 8866;
(c) P. Mathur, V.K. Singh, A.K. Singh, S.M. Mobin, C. Thöne, J. Organomet.
Chem. 691 (2006) 3336;
(d) P. Mathur, A.K. Singh, V.K. Singh, P. Singh, R. Rahul, S.M. Mobin, C. Thöne,
Organometallics 24 (2005) 4793.
(f) J. Kischel, I. Jovel, K. Mertins, A. Zapf, M. Beller, Org. Lett. 8 (2006) 19;
(g) I. Iovel, K. Mertins, J. Kischel, A. Zapf, M. Beller, Angew. Chem. 117 (2005)
3981 Angew. Chem. Int. Ed. 44 (2005) 3913.
[26] P. Mathur, V.D. Avasare, S.M. Mobin, J. Cluster Sci. 20 (2009) 399.
[27] P. Mathur, A.K. Bhunia, S.M. Mobin, V.K. Singh, C. Srinivasu, Organometallics
23 (2004) 3694.
[23] (a) M. Periasamy, C. Rameshkumar, U. Rhadhakrishnan, Tetrahedron Lett. 38
(1997) 7229;
[28] O. Chapman, in: , Organic Photochemistry, vol. 3, Marcel Dekker, Inc, New
York, 1973, p. 200.
(b) M. Periasamy, C. Rameshkumar, U. Rhadhakrishnan, J.-J. Brunet, J. Org.
Chem. 63 (1998) 4930;
(c) C. Rameshkumar, M. Periasamy, Organometallics 19 (2000) 2400;
(d) C. Rameshkumar, M. Periasamy, Tetrahedron Lett. 41 (2000) 2719;
[29] K.M. Driller, H. Klein, R. Jackstell, M. Beller, Angew. Chem. Int. Ed. 48 (2009) 6041.
[30] G. Doisneau, G. Balavoine, T.F. Khan, J. Organomet. Chem. 425 (1992) 113.
[31] G.M. Sheldrick, SHELXL-97, Program for Structure Refinement. University of
Göttingen, Germany, 1997.