Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Molecules ; 19(5): 6058-69, 2014 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-24828378

RESUMO

The compounds [3-(2-Bromocyclohex-2-enyloxy)prop-1-ynyl]-tert-butyl-dimethylsilane 3, [4-(2-bromocyclohex-2-en-1-yloxy)but-2-yn-1-yloxy]tert-butyldimethylsilane 5 and dimethyl 2-(2-bromocyclohex-2-enyl)-2-(3-(tert-butyldimethylsilanyl)prop-2-ynyl)malonate 9 were prepared and subjected to palladium-catalyzed intra-intermolecular cascade cross couplings incorporating bicyclopropylidene 10 under two types of conditions. In the presence of Pd(OAc)2, PPh3 and K2CO3 in acetonitrile at 80 °C, the products were indene analogues, cross-conjugated tetraenes 11, 12 and 13, respectively. The corresponding spirocyclopropanated tricycle 16 in dimethylformamide at 110 °C was obtained, albeit in low yield (24%), and observed as an equimolar mixture of diastereomers, whereas 14, 15 were not fully isolated.


Assuntos
Ciclização , Cicloexanonas/química , Paládio/química , Catálise , Ciclização/efeitos dos fármacos , Cicloexanonas/síntese química , Estrutura Molecular , Silanos/química , Estereoisomerismo
2.
Artigo em Inglês | MEDLINE | ID: mdl-24098235

RESUMO

In the title compound, C14H13ClN2O5S, the chlorine-substituted tetrahydrofuran ring adopts a twist conformation and the other tetra-hydro-furan ring an envelope conformation with the O atom as the flap. The pyrrolidine ring adopts a twist conformation. In the crystal, C-H⋯O hydrogen bonds link the mol-ecules into zigzag chains running along the b-axis direction.

3.
J Org Chem ; 78(7): 3349-54, 2013 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-23390958

RESUMO

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.


Assuntos
Azóis/química , Compostos de Benzilideno/química , Sulfonamidas/química , Triazenos/síntese química , Estrutura Molecular , Estereoisomerismo , Triazenos/química
4.
Acta Crystallogr Sect E Struct Rep Online ; 69(Pt 11): o1628-9, 2013 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-24454076

RESUMO

In the title compound, C15H15ClN2O5S, the tetra-hydro-furan 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 R (2) 2(20) and R (4) 4(26) rings, with adjacent rings running parallel to ac plane. Further C-H⋯O hydrogen bonds form a C(6) chain, linking the mol-ecules in the b-axis direction.

5.
Artigo em Inglês | MEDLINE | ID: mdl-22652543

RESUMO

Organic matter present in lignite samples collected from different depths (i.e. top, mid and bottom) of lignite source, Ilgin, 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.


Assuntos
Carvão Mineral/análise , Compostos Orgânicos/análise , Ácidos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
6.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 4): o1102-3, 2012 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-22589962

RESUMO

In the title compound, C(16)H(18)ClNO(3)S, the six-membered ring has a boat conformation. The two five-membered rings with the bridging O atom adopt envelope conformations, whereas the N-containing five-membered ring adopts a twisted conformation. In the crystal, C-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional network.

7.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 4): o994-5, 2011 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-21754251

RESUMO

In the title compound, C(15)H(16)BrNO(3)S, the boat form of the six-membered ring is almost symmetrical with respect to the ep-oxy bridge. The two five-membered rings generated by the ep-oxy bridge of the six-membered ring adopt envelope conformations, whereas the N-containing five-membered ring adopts a twisted conformation. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds.

8.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 5): o1085-6, 2011 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-21754407

RESUMO

In the tetra-hydro-isoindole moiety of the title compound, C(17)H(17)NO(3)S, the six-membered ring assumes a boat configuration and the -S=O group bridges the prow and stern of the boat. The phenyl ring is oriented at a dihedral angle of 83.2 (1)° with respect to the pyrrole ring. In the crystal, inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional network. A weak C-H⋯π inter-action involving the phenyl ring is also found. The crystal studied was an inversion twin.

9.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 6): o1304-5, 2011 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-21754707

RESUMO

In the title compound, C(9)H(12)BrNO(3)S, the two tetra-hydro-furan rings adopt envelope conformations, the pyrrolidine ring adopts a half-chair conformation and the six-membered ring is in a boat conformation. In the crystal, weak inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into R(2) (2)(8) and R(2) (2)(14) rings along the b-axis direction.

10.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 6): o1303, 2011 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-21754706

RESUMO

The title compound, C(22)H(21)NO(2), was synthesized from 4-meth-oxy-2-methyl-aniline and 2-hy-droxy-1,2-diphenyl-ethanone. In the title compound, the C-C-C-N-C backbone adopts an all-trans conformation. The crystal structure is stabilized by weak inter-molecular C-H⋯O hydrogen-bond inter-actions.

11.
Artigo em Inglês | MEDLINE | ID: mdl-17475544

RESUMO

The IR spectra of 5-chloro-10-oxa-3-thia-tricyclo[5.2.1.0(1,5)]dec-8-ene-3,3-dioxide (COTDO) has been recorded in the region 4000-525cm(-1). The optimized molecular geometry, frequency and intensity of the vibrational bands of COTDO in the ground state has been calculated using the Hartree-Fock and density functional using Becke's three-parameter hybrid method with the Lee, Yang, and Parr correlation functional methods with 6-31G(d,p) and 6-311G(d,p) basis sets. The harmonic vibrational frequencies were calculated and the scaled values have been compared with experimental IR spectra. The calculated geometrical parameters and harmonic vibrations are predicted in a very good agreement with the experimental data. The theoretical vibrational spectra of the title compound were interpreted by means of potential energy distributions (PEDs) using VEDA 4 program. With the help of this modern technique we were able to complete the assignment of the vibrational spectra of the title compound.


Assuntos
Compostos Heterocíclicos com 3 Anéis/química , Modelos Químicos , Compostos Heterocíclicos com 3 Anéis/síntese química , Espectroscopia de Infravermelho com Transformada de Fourier , Vibração
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...