Journal of Chemistry

Journal of Chemistry / 2013 / Article

Research Article | Open Access

Volume 2013 |Article ID 473968 | https://doi.org/10.1155/2013/473968

N. Zohreh, A. Alizadeh, M. Babaki, "One-Pot Solvent-Free Three-Component Synthesis of Conjugated Enaminones Containing Three Alkyl Carboxylate Groups", Journal of Chemistry, vol. 2013, Article ID 473968, 6 pages, 2013. https://doi.org/10.1155/2013/473968

One-Pot Solvent-Free Three-Component Synthesis of Conjugated Enaminones Containing Three Alkyl Carboxylate Groups

Academic Editor: Alexander Kornienko
Received05 Jun 2012
Revised14 Aug 2012
Accepted15 Aug 2012
Published25 Sep 2012

Abstract

An effective, one-pot, multicomponent, and solvent-free reaction for synthesis of conjugated enaminones containing three alkyl carboxylate groups is described. The reaction of primary amine, alkyl acetoacetate, and dialkyl acetylenedicarboxylate obtained the title compound in good yields in a short time.

1. Introduction

The multicomponent coupling reactions are emerging as a useful source for synthesizing small drug-like molecules with several levels of structural diversity [1]. They are also welcome in the context of economic and practical considerations. Moreover, multicomponent coupling strategies offer significant advantages over conventional linear-type syntheses [2].

-Functionalized enaminone derivatives are valuable precursors in organic synthesis, as they combine nucleophilicity of the enamine and electrophilicity of the enone functions [3, 4]. They are useful synthones for the synthesis of various pharmaceuticals [5, 6] and bioactive heterocycles [7, 8]. In particular, they have been utilized for the preparation of different important antibacterial, anticonvulsant, anti-inflammatory, and antitumour agents [9, 10]. They are important intermediates for the synthesis of several amino acids, aminols, peptides, and alkaloids [1115]. In addition, open-chain enaminones (the characteristic group is part of a chain) may be potential prodrugs since they could release biologically active primary amines [16].

Regarding their wide range of activity and importance, a variety of synthetic methods for enaminones [1723] has been developed. Surprisingly, no efficient solvent-free procedure currently exists for the synthesis of conjugated enaminones via a one-pot reaction.

2. Results and Discussion

Our research group investigated the synthesis of series of heterocycles based on the use of enaminones [2428]. Recently, we reported the synthesis of hydrazine-substituted enaminones [29] using diisipropyl diazodicarboxylate as an electron-deficient compound in a four-component reaction (Scheme 1).

473968.sch.001

In continuation, we decided to employ dialkyl acetylene dicarboxylate 3 as an electron-deficient compound in reaction with enaminones derived in situ from the solvent-free reaction of primary amines 1 and alkyl acetoacetate 2 for synthesis of conjugated enaminones 4. Our strategy is outlined in Scheme 2. The reaction proceeds under solvent-free condition at ambient temperature and in a very short time to produce conjugated enaminone 1,3-pentadiene-1,2,3-tricarboxylate derivatives in 80–90% yields.

473968.sch.002

To investigate the reaction scope and limitations, different types of primary amines, alkyl acetoacetates, and dialkyl acetylenedicarboxylates were used in the above reaction under the same condition. It was found that the reaction is general toward all of these components (Table 1). However, compound 4 could be produced as two and isomers, but in the mentioned condition; we recovered it as a single isomer in all examples (Figure 1).


Product 4RR′R′′Yield % 4

an-PrMeMe80
bn-PrMeEt85
cn-PrEtMe84
dn-PrEtEt85
eiPrMeMe86
fiPrMeEt90
giPrEtMe87
hAllylMeMe94
iAllylEtMe90

The structures of compounds 4ai were deduced from their elemental analysis, IR, and 1H and 13C NMR spectra that clearly indicated the formation of 1,3-pentadiene-1,2,3-tricarboxylate derivatives. The mass spectrum of 4a displayed a molecular ion peak at m/z 299, which was consistent with the 1 : 1 : 1 adduct of n-propyl amine, methyl acetoacetate, and dimethyl acetylenedicarboxylate. The most important absorption band in IR spectrum is due to the NH stretching frequency of amide moiety that is appeared at 3420 cm−1. Absorption bands at 1714, 1690, and 1645 cm−1 are due to the tree C=O of ester groups. In the 1H NMR spectrum of 4a, characteristic singlet signals at = 3.59, 3.71, and 3.78 ppm revealed that both of the methyl acetoacetate and dimethyl acetylenedicarboxylate are present in the product. The spectrum exhibited also three sharp singlet signals recognized as arising from C=CMe ( = 1.87 ppm), C=CH ( = 6.78 ppm), and NH ( = 9.63 ppm) groups. The n-propyl moiety gave rise to characteristic signals in the aliphatic region of the spectrum. The 1H decoupled 13C NMR spectrum of 4a showed 14 distinct resonances compatible with the proposed product. The signals at 165.76, 168.85, and 168.87 ppm are due to the three CO2Me. The 1H and 13C NMR spectra of compounds 4b–i were similar to those of 4a, except for the R, R′, and R′′ which exhibited characteristic signals with appropriate chemical shifts for the specific substitution patterns. Unfortunately, based on these spectroscopic data, we were not able to identify which isomer or is produce (Figure 1).

Although we have not established the mechanism of this reaction in an experimental manner, a possible explanation is proposed in Scheme 3. It is conceivable that initial event is the formation of enaminone 5 under solvent-free condition [30]. Subsequently, compound 5 reacts with dialkyl acetylenedicarboxylate to produce intermediate 6. Finally, tautomerization converts imine 6 to the product 4 (Scheme 3).

473968.sch.003

3. Experimental

All the chemicals used in the synthesis were of laboratory grade. Elemental analyses for C, H, and N were performed using a Herpes CHN-O-Rapid analyzer. Mass spectra were recorded on a FINNIGAN-MAT 8430 mass spectrometer operating at an ionization potential of 20 eV. 1H- and 13C-NMR spectra were measured (CDCl3 solution) with a Bruker DRX-500 AVANCE spectrometer at 500.1 and 125.7 MHz, respectively. IR spectra were recorded on a Shimadzu IR-460 spectrometer.

4. Typical Procedure for Preparation of Compound 4 (e.g. 4a)

To a magnetically stirred 5 mL flat bottom flask containing 0.06 gr of n-propyl amine (1 mmol), 0.12 gr methyl acetoacetate (1 mmol) was added. After 10 min, 0.14 gr dimethyl acetylenedicarboxylate (1 mmol) was added. The reaction mixture was allowed to stir 15 min. The product was separated by silica gel (Merck 230–240 mesh) column chromatography using n-hexane–EtOAc (5 : 1) mixture as eluent.

4.1. Trimethyl 4-(Propylamino)-1,3-pentadiene-1,2,3-tricarboxylate 4a

Pale yellow oil, yield 0.24 g (80%); IR (KBr): 3420 (NH), 1714, 1690 and 1645 (C=O), 1233 and 1133 (C–O); 1H-NMR (500.13 MHz, CDCl3): 1H NMR (500.13 MHz, CDCl3): 1.02 (3H, t, = 7.5 Hz, NCH2CH2Me), 1.67 (2H, sextet, = 7.2 Hz, NCH2CH2CH3), 1.87 (3H, s, C=CMe), 3.24–3.27 (2H, m, NCH2CH2CH3), 3.59 (3H, s, OMe), 3.71 (3H, s, OMe), 3.78 (3H, s, OMe), 6.78 (1H, s, C=CH), 9.63 (1H, s, NH); 13C NMR (125.7 MHz, CDCl3): = 11.41 (NCH2CH2Me), 16.41 (C=CMe), 23.32 (NCH2CH2CH3), 45.28 (NCH2CH2CH3), 50.44 (OMe), 51.55 (OMe), 52.59 (OMe), 88.32 (C=CMe), 126.61 (C=CH), 143.14 (C=CH), 162.44 (C=CMe), 165.76 (CO2Me), 168.85 (CO2Me), 168.87 (CO2Me); EI-MS: m/z (%) = 299 (10) [M+], 294 (19), 293 (25), 278 (20), 265 (8), 238 (13), 236 (40), 222 (7), 206 (22), 195 (26), 168 (15), 154 (61), 141 (100), 127 (45), 115 (33), 111 (16), 97 (15), 77 (43), 57 (42), 43 (95), 41 (47); Anal. Calc. for C14H21NO6 (299.32): C 56.18, H 7.07, N 4.68; found: C 56.21, H 7.09, N 4.60.

4.2. 1,2-Diethyl 3-Methyl 4-(Propylamino)-1,3-pentadiene-1,2,3-tricarboxylate 4b

Pale yellow oil, yield 0.27 g (85%); IR (KBr) ( , cm−1): 3495 (NH), 1712, 1677 and 1647 (C=O), 1237 and 1158 (C–O); 1H NMR (500.13 MHz, CDCl3): = 0.97 (3H, t, = 7.3 Hz, NCH2CH2Me), 1.21 (3H, t, = 6.9 Hz, OCH2Me), 1.25 (3H, t, = 7.0 Hz, OCH2Me), 1.62 (2H, sextet, = 7.1 Hz, NCH2CH2Me), 1.83 (3H, s, C=CMe), 3.18–3.22 (2H, m, NCH2CH2Me), 3.54 (3H, s, OMe), 4.08–4.14 (2H, m, OCH2Me), 4.15–4.24 (2H, m, OCH2Me), 6.71 (1H, s, C=CH), 9.57 (1H, s, NH); 13C NMR (125.7 MHz, CDCl3): = 11.32 (NCH2CH2Me), 14.05 (OCH2Me), 14.10 (OCH2Me), 16.32 (C=CMe), 23.26 (NCH2CH2CH3), 45.17 (NCH2CH2CH3), 50.25 (OMe), 60.26 (OCH2Me), 61.29 (OCH2Me), 88.45 (C=CMe), 126.97 (C=CH), 142.93 (C=CH), 162.18 (C=CMe), 165.40 (CO2Et), 168.19 (CO2Et), 168.81 (CO2Me); MS (EI, 70 eV): m/z (%) = 326 (23) [M+], 313 (12), 298 (29), 240 (6), 236 (19), 231 (3), 217 (4), 208 (17), 198 (2), 175 (2), 151 (20), 129 (31), 113 (16), 121 (10), 105 (10), 70 (15), 62 (18), 43 (100), 41 (19); Anal. Calc. for C16H25NO6 (327.37): C 58.70, H 7.70, N 4.28; found: C 58.78, H 7.73, N 4.30.

4.3. 3-Ethyl 1,2-Dimethyl 4-(Propylamino)-1,3-pentadiene-1,2,3-tricarboxylate 4c

Pale yellow oill, yield 0.26 g (84%); IR (KBr) ( , cm−1): 3425 (NH), 1714, 1686 and 1643 (C=O), 1229 and 1159 (C–O); 1H NMR (500.13 MHz, CDCl3): = 1.03 (3H, t, = 7.5 Hz, NCH2CH2Me), 1.16 (3H, t, = 7.2, OCH2Me), 1.66–1.69 (2H, m, NCH2CH2CH3), 1.89 (3H, s, C=CMe), 3.25–3.27 (2H, m, NCH2CH2CH3), 3.71 (3H, s, OMe), 3.78 (3H, s, OMe), 3.99–4.14 (2H, m, OCH2Me), 6.73 (1H, s, C=CH), 9.68 (1H, s, NH); 13C NMR (125.7 MHz, CDCl3): = 11.40 (NCH2CH2Me), 14.34 (OCH2Me), 16.42 (C=CMe), 23.29 (NCH2CH2CH3), 45.27 (NCH2CH2CH3), 51.48 (OMe), 52.47 (OMe), 58.82 (OCH2Me), 88.66 (C=CMe), 125.87 (C=CH), 143.46 (C=CH), 162.55 (C=CMe), 165.79 (CO2Et), 168.46 (CO2Me), 169.07 (CO2Me); MS (EI, 70 eV): m/z (%) = 313 (13) [M+], 298 (4), 282 (45), 268 (5), 252 (6), 250 (35), 238 (20), 222 (33), 206 (33), 194 (36), 180 (12), 164 (16), 152 (12), 138 (11), 125 (10), 108 (8), 82 (7), 59 (29), 43 (100); Anal. Calc. for C15H23NO6 (313.35): C 57.50, H 7.40, N 4.47%; found: C 57.54, H 7.44, N 4.46%.

4.4. Triethyl 4-(Propylamino)-1,3-penta diene-1,2,3-tricarboxylate 4d

Pale yellow oil, yield 0.29 g (85%); IR (KBr) ( , cm−1): 3485 (NH), 1712, 1687 and 1643 (C=O), 1231 and 1158 (C–O); 1H NMR (500.13 MHz, CDCl3): = 1.02 (3H, t, = 7.3 Hz, NCH2CH2Me), 1.17 (3H, t, = 6.9 Hz, OCH2Me), 1.26 (3H, t, = 7.0 Hz, OCH2Me), 1.30 (3H, t, = 7.0 Hz, OCH2Me), 1.62–169 (2H, m, NCH2CH2Me), 1.87 (3H, s, C=CMe), 3.18–3.30 (2H, m, NCH2CH2Me), 4.01–4.06 (2H, m, OCH2Me), 4.08–4.16 (2H, m, OCH2Me), 4.16–4.24 (2H, m, OCH2Me), 6.73 (1H, s, C=CH), 9.64 (1H, s, NH); 13C NMR (125.7 MHz, CDCl3): = 11.39 (NCH2CH2Me), 13.87 (OCH2Me), 14.15 (OCH2Me), 14.33 (OCH2Me), 16.40 (C=CMe), 23.31 (NCH2CH2CH3), 45.22 (NCH2CH2CH3), 58.80 (OCH2Me), 60.27 (OCH2Me), 61.33 (OCH2Me), 88.82 (C=CMe), 126.57 (C=CH), 143.27 (C=CH), 162.19 (C=CMe), 165.53 (CO2Et), 168.45 (CO2Et), 168.52 (CO2Et); MS (EI, 70 eV): m/z (%) = 339 (1) [M+], 326 (16), 298 (14), 240 (55), 236 (76), 231 (3), 217 (4), 203 (17), 188 (2), 175 (2), 161 (20), 149 (31), 129 (4), 113 (16), 104 (10), 85 (10), 71 (15), 62 (18), 43 (100), 41 (19); Anal. Calc. for C17H27NO6 (341.40): C 59.81, H 7.97, N 4.10%; found: C 59.85, H 7.99, N 4.11%.

4.5. Trimethyl 4-(Isopropylamino)-1,3-pentadiene-1,2,3-tricarboxylate 4e

Pale yellow oil, yield 0.26 g (86%); IR (KBr) ( , cm−1): 3425 (NH), 1715, 1688 and 1645 (C=O), 1243 and 1180 (C–O); 1H NMR (500.13 MHz, CDCl3): = 1.22 (6H, d, = 6.0 Hz, NCHMe2), 1.84 (3H, s, C=CMe), 3.51 (3H, s, OMe), 3.64 (3H, s, OMe), 3.71 (3H, s, OMe), 3.71-3.72 (1H, m, NCHMe2), 6.70 (1H, s, C=CH), 9.56 (1H, d, = 7.9 Hz, NH); 13C NMR (125.7 MHz, CDCl3): = 16.07 (C=CMe), 23.77 (NCHMe2), 24.06 (NCHMe2), 44.89 (NCHMe2), 50.31 (OMe), 51.48 (OMe), 52.50 (OMe), 88.14 (C=CMe), 126.66 (C=CH), 143.03 (C=CH), 161.31 (C=CMe), 162.55 (CO2Me), 165.66 (CO2Me), 168.73 (CO2Me); MS (EI, 70 eV): m/z (%) = 299 (4) [M+], 267 (5), 240 (7), 236 (5), 221 (5), 208 (6), 193 (6), 179 (6), 156 (11), 149 (20), 127 (5), 122 (5), 105 (10), 96 (10), 70 (13), 58 (25), 43 (100), 41 (28); Anal. Calc. for C14H21NO6 (299.32): C 56.18, H 7.07, N 4.68%; found: C 56.24, H 7.12, N 4.66%.

4.6. 1,2-Diethyl 3-Methyl 4-(Isopropylamino)-1,3-pentadiene-1,2,3-tricarboxylate 4f

Pale yellow oil, yield 0.29 g (90%); IR (KBr) ( , cm−1): 3385 (NH), 1712, 1690 and 1647 (C=O), 1240 and 1172 (C–O); 1H NMR (500.13 MHz, CDCl3): = 1.23 (3H, t, = 7.1 Hz, OCH2Me), 1.25 (6H, d, = 6.2 Hz, NCHMe2), 1.27 (3H, t, = 7.7 Hz, OCH2Me), 1.88 (3H, s, C=CMe), 3.56 (3H, s, OMe), 3.72–3.77 (1H, m, NCHMe2), 4.10–4.17 (2H, m, OCH2Me), 4.18–4.26 (2H, m, OCH2Me), 6.74 (1H, s, C=CH), 9.55 (1H, d, = 8.1 Hz, NH); 13C NMR (125.7 MHz, CDCl3): = 14.16 (2OCH2Me), 16.10 (C=CMe), 23.87 (NCHMe2), 24.11 (NCHMe2), 44.89 (NCHMe2), 50.29 (OMe), 60.33 (OCH2Me), 61.35 (OCH2Me), 88.37 (C=CMe), 127.30 (C=CH), 142.85 (C=CH), 161.09 (C=CMe), 165.49 (CO2Me), 168.24 (CO2Me), 168.82 (CO2Me); MS (EI, 70 eV): m/z (%) = 326 (35) [M+], 313 (17), 298 (7), 267 (16), 240 (2), 236 (4), 221 (9), 207 (16), 194 (21), 179 (23), 156 (22), 149 (25), 129 (6), 121 (4), 105 (18), 96 (20), 70 (13), 58 (2), 43 (100), 41 (43); Anal. Calc. for C16H25NO6 (327.37): C 58.70, H 7.70, N 4.28%; found: C 58.74, H 7.73, N 4.26%.

4.7. 3-Ethyl 1,2-Dimethyl 4-(Isopropylamino)-1,3-pentadiene-1,2,3-tricarboxylate 4g

Pale yellow oil, yield 0.27 g (87%); IR (KBr) ( , cm−1): 3295 (NH), 1712, 1657 and 1430 (C=O), 1230 (C–O); 1H NMR (500.13 MHz, CDCl3): = 1.13 (3H, t, = 7.0 Hz, OCH2Me), 1.23 (6H, d, = 6.0 Hz, NCHMe2), 1.87 (3H, s, C=CMe), 3.66 (3H, s, OMe), 3.73 (3H, s, OMe), 3.75-3.76 (1H, m, NCHMe2), 3.91–3.93 (1H, m, OCH2Me), 4.04–4.06 (1H, m, OCH2Me), 6.68 (1H, s, C=CH), 9.58 (1H, d, = 7.4 Hz, NH); 13C NMR (125.7 MHz, CDCl3): = 14.33 (OCH2Me), 16.13 (C=CMe), 23.77 (NCHMe2), 24.11 (NCHMe2), 44.90 (NCHMe2), 51.46 (OMe), 52.42 (OMe), 58.73 (OCH2Me), 88.52 (C=CMe), 125.94 (C=CH), 143.40 (C=CH), 161.45 (C=CMe), 165.74(CO2Et), 168.36 (CO2Me), 169.02 (CO2Me); MS (EI, 70 eV): m/z (%) = 313 (15) [M+], 298 (4), 267 (10), 240 (3), 236 (10), 220 (6), 209 (6), 194 (6), 179 (15), 156 (10), 149 (25), 129 (6), 121 (25), 105 (10), 96 (20), 70 (13), 58 (12), 43 (100), 41 (45); Anal. Calc. for C15H23NO6 (313.35): C 57.50, H 7.40, N 4.47%; found: C 57.52, H 7.44, N 4.46%.

4.8. Trimethyl 4-(Allylamino)-1,3-pentadiene-1,2,3-tricarboxylate 4h

Pale yellow oil, yield 0.28 g (94%); IR (KBr) ( , cm−1): 3420 (NH), 1715, 1690 and 1643 (C=O), 1237 and 1164 (C–O); 1H NMR (500.13 MHz, CDCl3): = 1.86 (3H, s, C=CMe), 3.60 (3H, s, OMe), 3.71 (3H, s, OMe), 3.78 (3H, s, OMe) 3.89-3.90 (2H, m, NCH2CHCH2), 5.21 (1H, d of d, = 10.0 Hz, = 2.2 Hz, NCH2CHCH2), 5.30 (1H, d of d, = 15.1 Hz, = 2.2 Hz, NCH2CHCH2), 5.81–5.94 (1H, m, NCH2CHCH2), 6.81 (1H, s, C=CH), 9.68 (1H, s, NH); 13C NMR (125.7 MHz, CDCl3): = 16.02 (C=CMe), 45.55 (NCH2CHCH2), 50.49 (OMe), 51.55 (OMe), 52.58 (OMe), 89.12 (C=CMe), 116.30 (NCH2CHCH2), 127.16 (C=CH), 134.11 (NCH2CHCH2), 142.75 (C=CH), 162.12 (C=CMe), 165.66 (CO2Me), 168.58 (CO2Me), 168.80 (CO2Me); MS (EI, 70 eV): m/z (%) = 297 (1) [M+], 298 (2), 279 (3), 245 (40), 236 (63), 219 (14), 206 (7), 188 (17), 174 (16), 160 (26), 150 (30), 127 (6), 112 (8), 103 (19), 85 (10), 71 (5), 62 (8), 43 (100), 41 (39); Anal. Calc. for C14H19NO6 (297.30): C 56.56, H 6.44, N 4.71%; found: C 56.57, H 6.46, N 4.75%.

4.9. 3-Ethyl 1,2-Dimethyl 4-(Allylamino)-1,3-pentadiene-1,2,3-tricarboxylate 4i

Pale yellow oil, yield 0.28 g (90%); IR (KBr) ( , cm−1): 3430 (NH), 1716, 1695 and 1644 (C=O), 1228 and 1158 (C–O); 1H NMR (500.13 MHz, CDCl3): = 1.15 (3H, t, = 6.8 Hz, OCH2Me), 1.84 (3H, s, C=CMe), 3.68 (3H, s, OMe), 3.75 (3H, s, OMe), 3.89–3.91 (2H, m, OCH2Me), 4.06–4.13 (1H, m, NC CHCH2), 4.15–4.18 (1H, m, NCH2CHCH2), 5.18 (1H, d of d, = 9.5 Hz, = 2.0 Hz, NCH2CHCH2), 5.28 (1H, d of d, = 14.9 Hz, = 2.0 Hz, NCH2CHCH2), 5.85–5.89 (1H, m, NCH2CHCH2), 6.74 (1H, s, C=CH), 9.69 (1H, s, NH); 13C NMR (125.7 MHz, CDCl3): = 14.29 (OCH2Me), 16.57 (C=CMe), 45.54 (NCH2CHCH2), 51.49 (OMe), 52.46 (OMe), 58.89 (OCH2Me), 89.4 (C=CMe), 116.26 (NCH2CHCH2), 126.46 (C=CH), 134.13 (NCH2CHCH2), 143.05 (C=CH), 162.23 (C=CMe), 165.68 (CO2Et), 168.34 (CO2Me), 168.78 (CO2Me); MS (EI, 70 eV): m/z (%) = 310 (5) [M+], 298 (9), 285 (22), 277 (5), 243 (5), 232 (5), 217 (4), 206 (17), 188 (14), 175 (7), 161 (20), 149 (32), 129 (6), 113 (19), 103 (12), 85 (10), 70 (15), 62 (18), 43 (100), 41 (90); Anal. Calc. for C15H21NO6 (311.33): C 57.87, H 6.80, N 4.50%; found: C 57.90, H 6.87, N 4.53%.

5. Conclusion

In summary, we have developed an efficient method for the synthesis of conjugated enaminones. The advantages of our work are as follows. (1) The reaction is performed under neutral condition that no acid/base or metal catalyst is required. (2) The reaction is in green chemistry category because of its solvent-free condition. (3) Three carboxylate functional groups are on the product, which is capable to convert to other functional groups. (4) Short reaction time and high yield of all derivatives are considerable. (5) The simplicity of the present procedure makes it an interesting alternative to the complex multistep approaches.

Conflict of Interests

The authors report no conflict of interests. The authors alone are responsible for the content and writing of the paper.

References

  1. A. Dömling and I. Ugi, “Multicomponent reactions with isocyanides,” Angewandte Chemie, vol. 39, no. 18, pp. 3169–3210, 2000. View at: Google Scholar
  2. L. Weber, K. Illgen, and M. Almstetter, “Discovery of new multi component reactions with combinatorial methods,” Synlett, no. 3, pp. 366–374, 1999. View at: Google Scholar
  3. R. K. Vohra, J. L. Renaud, and C. Bruneau, “Efficient synthesis of β-aminoacrylates and β-enaminones catalyzed by Zn(OAc)2·2H2O,” Collection of Czechoslovak Chemical Communications, vol. 70, no. 11, pp. 1943–1952, 2005. View at: Publisher Site | Google Scholar
  4. C. V. Stevens, B. Kesteleyn, E. R. Alonso, and N. de Kimpe, “Synthesis of 3-chloroanthranilates from α,γ,γ-trichloro-β-iminoesters,” Tetrahedron, vol. 57, no. 36, pp. 7685–7692, 2001. View at: Publisher Site | Google Scholar
  5. I. O. Edafiogho, J. A. Moore, M. S. Alexander, and K. R. Scott, “Nuclear magnetic resonance studies of anticonvulsant enaminones,” Journal of Pharmaceutical Sciences, vol. 83, no. 8, pp. 1155–1170, 1994. View at: Publisher Site | Google Scholar
  6. C. J. C. Connolly, J. M. Hamby, M. C. Schroeder et al., “Discovery and structure-activity studies of a novel series of pyrido[2,3-d]pyrimidine tyrosine kinase inhibitors,” Bioorganic and Medicinal Chemistry Letters, vol. 7, no. 18, pp. 2415–2420, 1997. View at: Publisher Site | Google Scholar
  7. J. P. Michael, C. B. Koning, D. Gravestock et al., “Enaminones: versatile intermediates for natural product synthesis,” Pure and Applied Chemistry, vol. 71, no. 6, pp. 979–988, 1999. View at: Google Scholar
  8. M. Uda, A. Momotake, and T. Arai, “1,3,5-tristyrylbenzene dendrimers: a novel model system to explore oxygen quenching in a highly organized environment,” Organic and Biomolecular Chemistry, vol. 1, no. 10, pp. 1635–1637, 2003. View at: Publisher Site | Google Scholar
  9. Y. F. Wang, T. Izawa, S. Kobayashi, and M. Ohno, “Stereocontrolled synthesis of (+)-negamycin from an acyclic homoallylamine by 1,3-asymmetric induction,” Journal of the American Chemical Society, vol. 104, no. 23, pp. 6465–6466, 1982. View at: Google Scholar
  10. J. P. Michael, C. B. de Koning, G. D. Hosken, and T. V. Stanbury, “Reformatsky reactions with N-arylpyrrolidine-2-thiones: synthesis of tricyclic analogues of quinolone antibacterial agents,” Tetrahedron, vol. 57, no. 47, pp. 9635–9648, 2001. View at: Publisher Site | Google Scholar
  11. D. Potin, F. Dumas, and J. D'Angelo, “New chiral auxiliaries: their use in the asymmetric hydrogenation of β-acetamidocrotonates,” Journal of the American Chemical Society, vol. 112, no. 9, pp. 3483–3486, 1990. View at: Google Scholar
  12. G. Bartoli, C. Cimarelli, E. Marcantoni, G. Palmieri, and M. Petrini, “Chemo- and diastereoselective reduction of β-enamino esters: a convenient synthesis of both cis- and trans-γ-amino alcohols and β-amino esters,” Journal of Organic Chemistry, vol. 59, no. 18, pp. 5328–5335, 1994. View at: Publisher Site | Google Scholar
  13. G. Palmieri and C. Cimarelli, “Stereoselective reduction of enantiopure β-enamino esters by hydride: a convenient synthesis of both enantiopure β-amino esters,” Journal of Organic Chemistry, vol. 61, no. 16, pp. 5557–5563, 1996. View at: Publisher Site | Google Scholar
  14. H. M. C. Ferraz, F. L. C. Pereira, F. S. Leite, M. R. S. Nunes, and M. E. Payret-Arrúa, “Synthesis of N-substituted pyrrole and tetrahydroindole derivatives from alkenyl β-dicarbonyl compounds,” Tetrahedron, vol. 55, no. 36, pp. 10915–10924, 1999. View at: Publisher Site | Google Scholar
  15. O. David, J. Blot, C. Bellec et al., “Enamino ester reduction: a short enantioselective route to pyrrolizidine and indolizidine alkaloids. Synthesis of (+)-laburnine, (+)-tashiromine, and (-)-isoretronecanol,” Journal of Organic Chemistry, vol. 64, no. 9, pp. 3122–3131, 1999. View at: Publisher Site | Google Scholar
  16. A. D. Fraser, “New drugs for the treatment of epilepsy,” Clinical Biochemistry, vol. 29, no. 2, pp. 97–110, 1996. View at: Publisher Site | Google Scholar
  17. R. S. Bhosale, P. A. Suryawanshi, S. A. Ingle et al., “Ionic liquid promoted synthesis of β-enamino ketones at room temperature,” Synlett, no. 6, pp. 933–935, 2006. View at: Publisher Site | Google Scholar
  18. Z. H. Zhang, L. Yin, and Y. M. Wang, “A general and efficient method for the preparation of β-enamino ketones and esters catalyzed by indium tribromide,” Advanced Synthesis and Catalysis, vol. 348, no. 1-2, pp. 184–190, 2006. View at: Publisher Site | Google Scholar
  19. E. Kleinpeter, “Conformational analysis of saturated six-membered oxygen-containing heterocyclic rings,” Advances in Heterocyclic Chemistry, no. 69, pp. 217–269, 1997. View at: Google Scholar
  20. A. R. Katritzky, A. E. Hayden, K. Kirichenko, P. Pelphrey, and Y. Ji, “A novel route to imidoylbenzotriazoles and their application for the synthesis of enaminones,” Journal of Organic Chemistry, vol. 69, no. 15, pp. 5108–5111, 2004. View at: Publisher Site | Google Scholar
  21. G. Bartoli, C. Cimarelli, R. Dalpozzo, and G. Palmieri, “A versatile route to β-enamino esters by acylation of lithium enamines with diethyl carbonate or benzyl chloroformate,” Tetrahedron, vol. 51, no. 31, pp. 8613–8622, 1995. View at: Publisher Site | Google Scholar
  22. D. S. Reddy, T. V. Rajale, K. Shivakumar, and J. Iqbal, “A mild and efficient method for the synthesis of vinylogous carbamates from alkyl azides,” Tetrahedron Letters, vol. 46, no. 6, pp. 979–982, 2005. View at: Publisher Site | Google Scholar
  23. F. Epifano, S. Genovese, and M. Curini, “Ytterbium triflate catalyzed synthesis of β-enaminones,” Tetrahedron Letters, vol. 48, no. 15, pp. 2717–2720, 2007. View at: Publisher Site | Google Scholar
  24. A. Alizadeh, F. Movahedi, and A. A. Esmaili, “A new method for the synthesis of functionalized maleimides,” Tetrahedron Letters, vol. 47, no. 26, pp. 4469–4471, 2006. View at: Publisher Site | Google Scholar
  25. A. Alizadeh, F. Movahedi, H. Masrouri, and L. G. Zhu, “A new method for the synthesis of functionalized 5-hydroxy-1,5-dihydro-2H- pyrrol-2-one: reaction of an enamine, derived from addition of a secondary amine to dibenzoylacetylene, with an arylsulfonyl isocyanate,” Synthesis, no. 20, pp. 3431–3436, 2006. View at: Publisher Site | Google Scholar
  26. A. Alizadeh, A. Rezvanian, and L. G. Zhu, “One-pot synthesis of 4,5-dihydro-1H-pyrrol-3-carboxamide derivativesviaafour-component reaction,” Tetrahedron, vol. 64, no. 2, pp. 351–355, 2008. View at: Publisher Site | Google Scholar
  27. A. Alizadeh, A. Rezvanian, and H. R. Bijanzadeh, “Synthesis of highly functionalized pyrrole derivatives via a four-component reaction of two primary amines and diketene in the presence of nitrostyrene,” Synthesis, no. 5, pp. 725–728, 2008. View at: Publisher Site | Google Scholar
  28. A. Alizadeh, M. Babaki, N. Zohreh, and A. Rezvanian, “One-pot synthesis of 3-oxo-3,4-dihydroquinoxalines bearing a sulfonamide or an amide group,” Synthesis, no. 23, pp. 3793–3796, 2008. View at: Publisher Site | Google Scholar
  29. A. Alizadeh, M. Babaki, and N. Zohreh, “Solvent-free synthesis of hydrazine-substituted enaminones via a one-pot four-component reaction,” Synthesis, no. 20, pp. 3295–3298, 2008. View at: Publisher Site | Google Scholar
  30. C. Bruneau, R. K. Vohra, and J. L. Renaud, “Tertiary 3-aminopropenones and 3-aminopropenoates: their preparation, with and without Lewis acids, from secondary amines and 1,3-diketo compounds,” Synthesis, no. 5, pp. 731–738, 2007. View at: Publisher Site | Google Scholar

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