Synthesis of α,β-unsaturated selenoesters by the reaction of acylzirconene chlorides with ArSeBr

Article abstract of DOI:10.1039/a905158i

α,β-Unsaturated selenoesters are prepared in good yields by the reaction of ArSeBr with acylzirconene chlorides.

Full text of DOI:10.1039/a905158i

View Article Online / Journal Homepage / Table of Contents for this issue
634 J. CHEM. RESEARCH (S), 1999
J. Chem. Research (S),
1999, 634^635y
Synthesis of a b-Unsaturated Selenoesters by
the Reaction of Acylzirconene Chlorides with
ArSeBr
Xian Huang* and Chun-Gen Liang
Department of Chemistry, Zhejiang University, (Campus Xixi), 34 Tianmushan Lu, Hangzhou,
310028, P. R. China.
a b-Unsaturated selenoesters are prepared in good yields by the reaction of ArSeBr with acylzirconene chlorides.
1
Selenoesters are useful synthetic intermediates having been
employed,1 for example, as mild acyltransfer reagents,2
building blocks for heterocyclic compounds (axaze)3 and
precursors of acyl radicals.4 Recently we have revealed that
the selenocarbonylation addition reaction of selenoesters
to nonactivated terminal alkynes under the catalysis of
CuX produces (Z) arylseleno a; b-unsaturated ketones in
high selectivity and high yields.5 In addition, Byeon6
reported that a; b-unsaturated selenoesters served as
dienophiles in Diels^Alder reactions with a variety of 1,3-
dienes with reverse regioselectivity. In contrast to their
growing utility in organic synthesis, the preparative
methods are limited: they have usually been prepared by
conventional methods based on the reaction of selenolate
anions with carboxylic acids and their derivatives,7 and
other methods, such as alkylation of selenocarboxylates,8
reaction of carboxylic acid with tributylphosphine,9
Co2(CO)8 mediated carbonylation of diselenides,10 reaction
of esters or aldehydes with Bun2AlSeBun.11
in the H NMR spectra (J ˆ 16 17 Hz). Only the E isomer
was observed due to the hydrozirconation and insertion
reaction of CO with retention of con¢guration
In conclusion, a new convenient synthetic method for
a; b-unsaturated selenoesters has been developed by the
reaction of acylzirconene chlorides with ArSeBr. Compared
to other reported methods, this method has the advantages
of mild reaction conditions, available reagents, high yield
and a lower reaction time. Further work on addition of
a; b-unsaturated selenoesters to terminal acetylenes is in
progress.
Experimental
1H NMR spectra were recorded on PMX-60 spectrometer using
CDCl3 as the solvent with TMS as an internal standard. J Values
are given in Hz. IR spectra were obtained on
a PE-683
spectrophotometer. Mass spectra were obtained on an HP 5989A
spectrometer. Melting points were uncorrected. Elemental analyses
were conducted using a Yanaco MT-3CHN elemental analyser.
All reactions were carried out in pre-dried glassware (150 8C, 4 h)
and cooled under a stream of dry nitrogen. CH2Cl2 was distilled over
CaH2.
As an extension of our study on the addition of
selenoesters to terminal acetylene, we needed a practical
and convenient preparative method for selenoesters other
than arylselenoester sources. Here we report a new con-
venient synthesis of a; b-unsaturated selenoesters from the
reaction of acylzirconene chlorides with the electrophilic
selenium bromides (ArSeBr) as shown in Scheme 1.
General Procedure for the Synthesis of 2a^2i.öTo a suspension of
[Cp2ZrHCl] (512 mg, 2.0 mmol) in CH2Cl2 (8 ml) was added terminal
acetylene (2.0 mmol), and the resulting mixture was stirred for 30 min
at ambient temperature. After the mixture had been stirred under an
atmosphere of CO for 2 h the mixture was added to ArSeBr13
(2.0 mmol) in CH2Cl2 via syringe at room temperature and stirred
for 10 min. After reaction, the mixture was treated with aqueous
NH4Cl and extracted with ether (3 Â 10 ml), the combined ethereal
extracts were dried over MgSO4 and concentrated under reduced
pressure, the crude product was puri¢ed by preparative TLC on silica
O
R1
H
H
ZrCp2HCl
CH2Cl2
CO
R1C CH
R1
ZrCp2Cl
ZrCp2Cl
1
2
ArSeBr
room temp.
gel using CCl4 as eluant.
2a: Oil.
O
1
n
max=cm
:
1709 ꢀCˆO†. dH 0.82^1.70 (7H, m,
R = C4H9, C5H11, Ph
Ar = Ph, p-CH3C6H4, p-ClC6H4
CH2CH2CH3), 2.25 (2H, m, CH2), 6.06 (1H, d, J 16 Hz), 6.80 (1H,
dt, J 16, 6.5 Hz), 7.15^7.50 (5H, m, C6H5). MS(EI) m/z: 269
(M ‡ 1, 5%), 111 (M SePh, 100%). Found: C, 58.39; H, 6.07. Calc.
R1
SeAr
for C13H16OSe: C, 58.43; H, 6.03%.
Scheme 1
1
2b: Oil.
n
max=cm
:
1720 ꢀCˆO†. dH 0.80^1.70 (7H, m,
CH2CH2CH3), 1.90^2.30 (2H, m, CH2), 6.00 (1H, d, J 16.3 Hz), 6.90
(1H, dt, J 16.3, 6.5 Hz), 7.35 (4H, m, C6H4). MS(EI) m/z: 303
(M ‡ 1, 2%), 111 (M p-ClPhSe), 100%). Found: C, 51.63; H, 4.97.
Calc. for C13H15ClOSe: C, 51.76; H, 5.01%.
Acylzirconene chloride derivatives 1, which are used as an
``unmasked'' acyl anion for organic synthesis, can be con-
veniently prepared through sequential treatment of alkynes
with zirconene hydrochloride (Schwarts reagent) and carbon
monoxide.12 Here, we have investigated the reactivity of 1
with ArSeBr. When 1 was added to ArSeBr in CH2Cl2,
Table 1 Synthesis of a b-unsaturated selenoesters 2a^2i
the a; b-unsaturated carboxylate selenoesters
2
were
Products
R1
Ar
Yieldsa(%)
obtained immediately (see Table 1).
As the data in Table 1 show this method a¡ords a variety
of a; b-unsaturated selenoesters in good yield and more
importantly the reaction can be performed rapidly at room
temperature. The con¢guration of the products could be
con¢rmed by the analysis of the coupling constant data
2a
2b
2c
2d
2e
2f
2g
2h
2i
C4H9
C4H9
C4H9
C5H11
C5H11
C5H11
Ph
C6H4
75
79
82
83
76
84
84
80
85
p-ClC6H4
p-CH3C6H5
C6H4
p-CH3C6H4
p-ClC6H4
C6H4
* To receive any correspondence.
Ph
Ph
p-CH3C6H4
p-ClC6H4
This is a Short Paper as de¢ned in the Instructions for Authors,
Section 5.0 [see J. Chem. Research (S), 1999, Issue 1]; there is
therefore no corresponding material in J. Chem. Research (M).
a Isolated yields based on ArSeBr.

View Article Online
J. CHEM. RESEARCH (S), 1999 635
1
2c: Oil.
n
max=cm
:
1700 ꢀCˆO†. dH 0.80^1.70 (7H, m,
Project 29772007 was supported by the National Nature
Science Foundation of China and this work was also
supported by The National Nature Science Foundation
of Zhejiang Province.
CH2CH2CH3), 1.87^2.45 (5H, m), 6.10 (1H, d, J 16 Hz), 6.90 (1H,
dt, J 16, 6.5 Hz), 7.20 (4H, m, C6H4). MS(EI) m/z: 283 (M ‡ 1, 1.3%),
111 (M p-CH3PhSe, 100%). Found: C, 59.82; H, 6.41. Calc. for
C14H18OSe: C, 59.79; H, 6.45%.
1
2d: Oil.
n
max=cm
:
1703 ꢀCˆO†. dH 0.67^1.67 (9H, m,
CH2CH2CH2CH3), 2.05 (2H, m, CH2), 6.04 (1H, d, J 16 Hz), 6.84
(1H, dt, J 16, 6.5 Hz), 7.34 (5H, m, C6H5). MS(EI) m/z: 283
(M ‡ 1, 5%), 125 (M PhSe, 100%). Found: C, 59.87; H, 6.41. Calc.
References
1
2
3
4
5
6
7
For a review: C. Najera and M. Yus, Org. Prep. Proced. Int.,
1995, 27, 385 and references cited therein.
A. F. Sviridov, M. S. Ermolenko, D. V. Yashunsky and N. K.
Kochetkov, Tetrahedron Lett., 1983, 24, 4355.
A. P. Kozikowski and A. Ames, J. Am. Chem. Soc., 1980, 102,
860; Tetrahedron, 1985, 41, 4821.
D. L. Boger and R. J. Mathvink, J. Am. Chem. Soc., 1985,
107, 3285.
C. Q. Zhao, X. Huang and J. B. Meng, Tetrahedron Lett.,
1998, 39, 1933.
C. H. Byeon, C. Y. Ellis, D. A. Hart and D. J. Li, Synlett,
1998, 596.
(a) C. Paulmier, Selenium Reagents and Intermediates in
Organic Synthesis, Pergamon Press, Oxford, 1986; (b) S. Kato,
T. Murai and T. M. Ishida, Org. Prep. Proced. Int., 1986, 18,
369.
for C14H18OSe: C, 59.79; H, 6.45%.
1
2e: Oil.
nmax=cm
:
1705 ꢀCˆO†. dH 0.67^1.67 (9H, m,
CH2CH2CH2CH3), 1.86^2.45 (5H, m, CH2 ‡ CH3), 6.03 (1H, d, J
16 Hz), 6.87 (1H, dt, J 16, 7.0 Hz), 7.20 (4H, m, C6H4). MS(EI) m/z:
297 (M ‡ 1, 6.5%), 125 (M p-CH3PhSe, 100%). Found: C, 60.86;
H, 6.75. Calc. for C15H20OSe: C, 61.01; H, 6.83%.
1
2f: Oil.
nmax=cm
:
1717 ꢀCˆO†. dH 0.67^1.67 (9H, m,
CH2CH2CH2CH3), 2.10 (2H, m, CH2), 6.03 (1H, d, J 16 Hz), 6.87
(1H, dt, J 16, 7.0 Hz), 7.36 (4H, m, C6H4). MS(EI) m/z: 317
(M ‡ 1, 1.5%), 125 (M p-ClPhSe), 100%). Found: C, 53.13; H, 5.36.
Calc. for C14H17ClOSe: C, 53.26; H, 5.43%.
2g: Mp 79^81 8C (lit14 79±91 8C). nmax=cm 1: 1700 (CˆO†. dH 6.70
(1H, d, J 16 Hz), 7.30^7.73 (11H, m, C6H5 ‡ C6H5 ‡ 1H).
2h: Mp 83^85 8C (lit14 83±85 8C). nmax=cm 1: 1709 (CˆO†. dH 2.33
(3H, s, CH3), 6.60 (1H, d,
J 16.5 Hz), 7.15^7.5 (10H, m,
8
9
H. Ishihara, S. Muto and S. Kato, Synthesis, 1986, 128.
D. Batty and D. Crich, Synthesis, 1990, 273.
C6H4 ‡ C6H5 ‡ 1H).
2i: Mp 92^94 8C. nmax=cm 1: 1709 ꢀCˆO†. dH 6.43 (1H, d, J
16.5 Hz), 7.30^7.70 (10H, m, C6H4 ‡ C6H5 ‡ 1H†. MS(EI) m/z:
323 (M ‡ 1, 1%), 131 (M p-ClPhSe), 100%). Found: C, 55.91;
H, 3.37. Calc. for C15H11ClOSe: C, 56.01; H, 3.45%.
10 H. Takahashi, K. Ohe, S. Uemuraand and N. Sugita, J.
Organomet. Chem., 1987, 334, C43.
11 T. Inoue, T. Takedo, N. Kambe, A. Ogawa, I. Kyu and N.
Sonodal, J. Org. Chem., 1994, 59, 5824.
12 S. Harada, T. Taguchi, N. Tabuchi, K. Narita and Y.
Hanzawa, Angew. Chem., Int. Ed., 1998, 37, 1696.
13 M. Fiese and L. F. Fieser, Reagents for Organic Synthesis,
John Wiley & Sons, vol. 5, 1975, p. 518.
Received, 28th June 1999; Accepted, 15th July 1999
Paper E/9/05158I
14 W. L. Bao and Y. M. Zhang, Synth. Commun., 1995, 25, 143.