A metal-free, thermal, intramolecular Diels–Alder (IMDA) reaction of furan in aqueous media witho... more A metal-free, thermal, intramolecular Diels–Alder (IMDA) reaction of furan in aqueous media without the use of microwave irradiation was investigated. Protection of the amine functionality and the cycloaddition reaction were performed as a one-pot, two-component process. Various nitrogen-protecting groups and their electronic and steric effects on the cycloaddition reaction were studied. The protection–intramolecular Diels–Alder reaction sequence proceeds under environmentally benign aqueous conditions, which are tolerated by substrates with a broad range of nitrogen-protecting groups such as benzyloxycarbonyl (Cbz), trityl, tert-butoxycarbonyl (Boc), trifluoroacetyl, tosyl, mesyl, and p-nosyl [(4-nitrophenyl)sulfonyl]. This study allowed the development of a stereoselective, tandem allylamine isomerization–Diels–Alder cycloaddition sequence leading to the rapid assembly of complex nitrogen-containing heterocycles in a simple one-pot process.
R factor = 0.068; wR factor = 0.192; data-to-parameter ratio = 15.9. In the title compound, C15H1... more R factor = 0.068; wR factor = 0.192; data-to-parameter ratio = 15.9. In the title compound, C15H15ClN2O5S, the tetrahydrofuran ring adopts an envelope conformation with the O atom as the flap. The pyrrolidine ring adopts an envelope conformation with the chlorine-substituted C atom as the flap. In the crystal, two types of C—H O hydrogen bonds generate R22(20) and R44(26) rings, with adjacent rings running parallel to ac plane. Further C—H O hydrogen bonds form a C(6) chain, linking the molecules in the b-axis direction. Related literature
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2012
Organic matter present in lignite samples collected from different depths (i.e. top, mid and bott... more Organic matter present in lignite samples collected from different depths (i.e. top, mid and bottom) of lignite source, Ilgın, Konya province, was examined by using subtractive-FTIR-ATR spectroscopy. FTIR spectra were recorded on (i) original samples, (ii) the samples dried at 105 °C and (iii) the samples acid-treated and dried. After a combustion process performed for each sample at 650 °C for 15 min, the spectra of samples were recorded and subtracted from the spectra of untreated samples. Hence, a software-based subtraction made it possible to acquire a representative spectra related with organic matter. As the contribution of the bands related with inorganic constituents in lignite samples were eliminated after spectrum-subtraction procedure, difference-spectra led analyzing the spectra related with organic matter in lignite samples, reasonably. Furthermore, the bands related with acidic functional groups, aromatic and aliphatic structures were analyzed on the basis of difference-spectra, easily. From the difference-spectra it was shown that an acid-treatment process under mild conditions caused shift in some specific bands related with carbonyl groups of carboxyls so that the band at around 1710 cm(-1) arisen, while the intensity of the band at around 1420 cm(-1) was diminished. Through the acid-treatment process, acidic groups in lignite samples from different depths were thought to be turned into similar forms by protonation and/or stripping of metal ions originally bonded. Difference-spectra acquired for acid-treated samples made it possible to evaluate the form of carboxylic acid groups present in the studied samples under specific environmental conditions. Hence, a facile and environmentally-friendly methodology was used to analyze organic matter in lignite by using FTIR spectra, and valuable information was acquired about the aliphatic, aromatic and acidic character of the studied lignite samples collected from different depths. The proposed methodology seems to be promising in acquiring approximate representative spectra for lignite organic matter by using little or no chemicals.
The Fourier transform infrared (FT-IR) spectrum of 6-chloro-8-thia-1,4-epoxybicyclo[4.3.0]non-2-e... more The Fourier transform infrared (FT-IR) spectrum of 6-chloro-8-thia-1,4-epoxybicyclo[4.3.0]non-2-ene has been recorded in the region 4000–525 cm. The optimised geometry, frequency and intensity of the vibrational bands of the title compound have been calculated using the ab initio Hartree–Fock and the density functional theory method with 6-31G(d,p) and 6-311G(d,p) basis set levels. The harmonic vibrational frequencies were calculated and the scaled values
In-situ-generated neutral 1-(benzylideneamino)- and novel anionic 1-(sulfonimido)-azolylidenes re... more In-situ-generated neutral 1-(benzylideneamino)- and novel anionic 1-(sulfonimido)-azolylidenes react with organic azides to afford diverse classes of push-pull triazenes and triazene salts. The scope of the heterocyclic core and substituents at the N1 and N3 positions of NHC precursors together with the thermal properties of resulting compounds were examined.
Thermal intramolecular Diels–Alder (IMDA) reaction of furan cored compounds has been further inve... more Thermal intramolecular Diels–Alder (IMDA) reaction of furan cored compounds has been further investigated; a series of key precursors to the IMDA reaction of furan diene (9a–c) have been prepared via facile alkylation and protection. While the cycloaddition process for (10a–c) was afforded in hot toluene, a commercial microwave (2450 MHz) was used for the synthesis of (12a–b). Treatment of fused oxy- and thio-heterotricycles (12a–b) with borontrifluoride-etherate in dichloromethane at −78°C cleaved epoxy bridge and concomitant aromatisation gave the isobenzo-furan and thiophene (13a–b) in 72–76% yields respectively.
Page 1. A FACILE SYNTHESIS OF HETEROTRICYCLES FROM FURFURYLBROMOALKENES USING THERMAL IMDA CYCLO ... more Page 1. A FACILE SYNTHESIS OF HETEROTRICYCLES FROM FURFURYLBROMOALKENES USING THERMAL IMDA CYCLO ADDITION Aydin Demircan,* Muhsin Karaarslan and Ersen Tura? ... We also would like to thanks Prof. Dr. Hasan SECHEN for his interest. 1. Β. ...
A metal-free, thermal, intramolecular Diels–Alder (IMDA) reaction of furan in aqueous media witho... more A metal-free, thermal, intramolecular Diels–Alder (IMDA) reaction of furan in aqueous media without the use of microwave irradiation was investigated. Protection of the amine functionality and the cycloaddition reaction were performed as a one-pot, two-component process. Various nitrogen-protecting groups and their electronic and steric effects on the cycloaddition reaction were studied. The protection–intramolecular Diels–Alder reaction sequence proceeds under environmentally benign aqueous conditions, which are tolerated by substrates with a broad range of nitrogen-protecting groups such as benzyloxycarbonyl (Cbz), trityl, tert-butoxycarbonyl (Boc), trifluoroacetyl, tosyl, mesyl, and p-nosyl [(4-nitrophenyl)sulfonyl]. This study allowed the development of a stereoselective, tandem allylamine isomerization–Diels–Alder cycloaddition sequence leading to the rapid assembly of complex nitrogen-containing heterocycles in a simple one-pot process.
R factor = 0.068; wR factor = 0.192; data-to-parameter ratio = 15.9. In the title compound, C15H1... more R factor = 0.068; wR factor = 0.192; data-to-parameter ratio = 15.9. In the title compound, C15H15ClN2O5S, the tetrahydrofuran ring adopts an envelope conformation with the O atom as the flap. The pyrrolidine ring adopts an envelope conformation with the chlorine-substituted C atom as the flap. In the crystal, two types of C—H O hydrogen bonds generate R22(20) and R44(26) rings, with adjacent rings running parallel to ac plane. Further C—H O hydrogen bonds form a C(6) chain, linking the molecules in the b-axis direction. Related literature
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2012
Organic matter present in lignite samples collected from different depths (i.e. top, mid and bott... more Organic matter present in lignite samples collected from different depths (i.e. top, mid and bottom) of lignite source, Ilgın, Konya province, was examined by using subtractive-FTIR-ATR spectroscopy. FTIR spectra were recorded on (i) original samples, (ii) the samples dried at 105 °C and (iii) the samples acid-treated and dried. After a combustion process performed for each sample at 650 °C for 15 min, the spectra of samples were recorded and subtracted from the spectra of untreated samples. Hence, a software-based subtraction made it possible to acquire a representative spectra related with organic matter. As the contribution of the bands related with inorganic constituents in lignite samples were eliminated after spectrum-subtraction procedure, difference-spectra led analyzing the spectra related with organic matter in lignite samples, reasonably. Furthermore, the bands related with acidic functional groups, aromatic and aliphatic structures were analyzed on the basis of difference-spectra, easily. From the difference-spectra it was shown that an acid-treatment process under mild conditions caused shift in some specific bands related with carbonyl groups of carboxyls so that the band at around 1710 cm(-1) arisen, while the intensity of the band at around 1420 cm(-1) was diminished. Through the acid-treatment process, acidic groups in lignite samples from different depths were thought to be turned into similar forms by protonation and/or stripping of metal ions originally bonded. Difference-spectra acquired for acid-treated samples made it possible to evaluate the form of carboxylic acid groups present in the studied samples under specific environmental conditions. Hence, a facile and environmentally-friendly methodology was used to analyze organic matter in lignite by using FTIR spectra, and valuable information was acquired about the aliphatic, aromatic and acidic character of the studied lignite samples collected from different depths. The proposed methodology seems to be promising in acquiring approximate representative spectra for lignite organic matter by using little or no chemicals.
The Fourier transform infrared (FT-IR) spectrum of 6-chloro-8-thia-1,4-epoxybicyclo[4.3.0]non-2-e... more The Fourier transform infrared (FT-IR) spectrum of 6-chloro-8-thia-1,4-epoxybicyclo[4.3.0]non-2-ene has been recorded in the region 4000–525 cm. The optimised geometry, frequency and intensity of the vibrational bands of the title compound have been calculated using the ab initio Hartree–Fock and the density functional theory method with 6-31G(d,p) and 6-311G(d,p) basis set levels. The harmonic vibrational frequencies were calculated and the scaled values
In-situ-generated neutral 1-(benzylideneamino)- and novel anionic 1-(sulfonimido)-azolylidenes re... more In-situ-generated neutral 1-(benzylideneamino)- and novel anionic 1-(sulfonimido)-azolylidenes react with organic azides to afford diverse classes of push-pull triazenes and triazene salts. The scope of the heterocyclic core and substituents at the N1 and N3 positions of NHC precursors together with the thermal properties of resulting compounds were examined.
Thermal intramolecular Diels–Alder (IMDA) reaction of furan cored compounds has been further inve... more Thermal intramolecular Diels–Alder (IMDA) reaction of furan cored compounds has been further investigated; a series of key precursors to the IMDA reaction of furan diene (9a–c) have been prepared via facile alkylation and protection. While the cycloaddition process for (10a–c) was afforded in hot toluene, a commercial microwave (2450 MHz) was used for the synthesis of (12a–b). Treatment of fused oxy- and thio-heterotricycles (12a–b) with borontrifluoride-etherate in dichloromethane at −78°C cleaved epoxy bridge and concomitant aromatisation gave the isobenzo-furan and thiophene (13a–b) in 72–76% yields respectively.
Page 1. A FACILE SYNTHESIS OF HETEROTRICYCLES FROM FURFURYLBROMOALKENES USING THERMAL IMDA CYCLO ... more Page 1. A FACILE SYNTHESIS OF HETEROTRICYCLES FROM FURFURYLBROMOALKENES USING THERMAL IMDA CYCLO ADDITION Aydin Demircan,* Muhsin Karaarslan and Ersen Tura? ... We also would like to thanks Prof. Dr. Hasan SECHEN for his interest. 1. Β. ...
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