Coupling reaction between aromatic electrophiles and nucleophiles: intermediates, products and an... more Coupling reaction between aromatic electrophiles and nucleophiles: intermediates, products and an unusual nitro group shift.
The first attempt to compare Boulton–Katritzky rearrangement with N-1/N-3-oxide tautomerism: form... more The first attempt to compare Boulton–Katritzky rearrangement with N-1/N-3-oxide tautomerism: formation of isomeric products in the reaction between 2-aminothiazoles and 7-chloro-4,6-dinitrobenzofuroxan.
Ruthenium complexes have proved to exhibit antineoplastic activity, related to the interaction of... more Ruthenium complexes have proved to exhibit antineoplastic activity, related to the interaction of the metal ion with DNA. In this context, synthetic and theoretical studies on ruthenium binding modes of thymine acetate (THAc) have been focused to shed light on the structure-activity relationship. This report deals with the reaction between dihydride ruthenium mer-[Ru(H)2(CO)(PPh3)3], 1 and the thymine acetic acid (THAcOH) selected as model for nucleobase derivatives. The reaction in refluxing toluene between 1 and THAcOH excess, by H2 release affords the double coordinating species κ1-(O)THAc-, κ2-(O,O)THAc-[Ru(CO)(PPh3)2], 2. The X-ray crystal structure confirms a simultaneous monohapto, dihapto- THAc coordination in a reciprocal facial disposition. Stepwise additions of THAcOH allowed to intercept the monohapto mer-κ1(O)THAc-Ru(CO)H(PPh3)3] 3 and dihapto trans(P,P)-κ2(O,O)THAc-[Ru(CO)H(PPh3)2] 4 species. Nuclear magnetic resonance (NMR) studies, associated with DFT (Density Functi...
The chiral (R)-10-hydroxystearic acid ((R)-10-HSA) is a positional homologue of both (R)-12-HSA a... more The chiral (R)-10-hydroxystearic acid ((R)-10-HSA) is a positional homologue of both (R)-12-HSA and (R)-9-HSA with the OH group in an intermediate position. While (R)-12-HSA is one of the best-known low-molecular-weight organogelators, (R)-9-HSA is not, but it forms crystals in several solvents. With the aim to gain information on the structural role of hydrogen-bonding interactions of the carbinol OH groups, we investigated the behavior of (R)-10-HSA in various solvents. This isomer displays an intermediate behavior between (R)-9 and (R)-12-HSA, producing a stable gel exclusively in paraffin oil, while it crystallizes in other organic solvents. Here, we report the X-ray structure of a single crystal of (R)-10-HSA as well as some structural information on its polymorphism, obtained through X-ray Powder Diffraction (XRPD) and Infrared Spectroscopy (IR). This case study provides new elements to elucidate the structural determinants of the microscopic architectures that lead to the for...
4,6-Dinitro-7-(thiazol-2-ylamino)benzo[c][1,2,5]oxadiazole 1-oxide was synthesized by a SNAr reac... more 4,6-Dinitro-7-(thiazol-2-ylamino)benzo[c][1,2,5]oxadiazole 1-oxide was synthesized by a SNAr reaction between 7-chloro-4,6-dinitrobenzofuroxan and 2-aminothiazole. The structure of the newly synthesized compound (45% yield) was elucidated based on 1H-NMR, 13C-NMR, NOESY-1D, ESI-MS, UV-Vis, and FT-IR techniques.
Ovarian cancer remains the leading cause of mortality among gynecological tumors. Estrogen recept... more Ovarian cancer remains the leading cause of mortality among gynecological tumors. Estrogen receptor beta (ERβ) expression has been suggested to act as a tumor suppressor in epithelial ovarian cancer by reducing both tumor growth and metastasis. ERβ expression abnormalities represent a critical step in the development and progression of ovarian cancer: for these reasons, its re-expression by genetic engineering, as well as the use of targeted ERβ therapies, still constitute an important therapeutic approach. 3-{[2-chloro-1-(4-chlorobenzyl)-5-methoxy-6-methyl-1H-indol-3-yl]methylene}-5-hydroxy-6-methyl-1,3-dihydro-2H-indol-2-one, referred to here as compound 3, has been shown to have cytostatic as well cytotoxic effects on various hormone-dependent cancer cell lines. However, the mechanism of its anti-carcinogenic activity is not well understood. Here, we offer a possible explanation of such an effect in the human ovarian cancer cell line IGROV1. Chromatin binding protein assay and li...
The compound 1,1’,1’’-(2’,4’-dinitro-[1,1’-biphenyl]-2,4,6-triyl)tripiperidine was synthesized by... more The compound 1,1’,1’’-(2’,4’-dinitro-[1,1’-biphenyl]-2,4,6-triyl)tripiperidine was synthesized by SEAr/SNAr reaction between 1-fluoro-2,4-dinitrobenzene and 1,3,5-tris(N-piperidinyl)benzene. The structure of the newly synthesized compound was elucidated based on 1H-NMR, 13C-NMR, ESI-MS, UV-Vis and IR spectroscopy.
3,5-Dimethoxy-2-[(4-methoxyphenyl)diazenyl]phenol was synthesized by an azo-coupling reaction bet... more 3,5-Dimethoxy-2-[(4-methoxyphenyl)diazenyl]phenol was synthesized by an azo-coupling reaction between 3,5-dimethoxyphenol and 4-methoxy benzenediazonium tetrafluoroborate. The structure of newly synthesized compound was elucidated based on 1H NMR, 13C NMR, ESI-MS, UV-Vis and FT-IR.
The fight against cancer is one of the most challenging tasks currently for lots of researchers i... more The fight against cancer is one of the most challenging tasks currently for lots of researchers in many fields, such as pharmaceuticals, medicine, and chemicals [...]
9-Hydroxystearic acid (9-HSA) is an endogenous cellular lipid that possesses antiproliferative an... more 9-Hydroxystearic acid (9-HSA) is an endogenous cellular lipid that possesses antiproliferative and selective effects against cancer cells. A series of derivatives were synthesized in order to investigate the effect of the substituent in position 9 and on the methyl ester functionality on the biological activity. The two separate enantiomers of methyl 9-hydroxystearate and of methyl 9-aminostearate showed antiproliferative activity against the HT29 cell line. This indicates the importance of position 9 groups being able to make hydrogen bonding with the molecular target. Further, this effect must be preserved when the carboxy group of 9-HSA is esterified. The biological tests showed that the amines, contrarily to methyl esters, resulted in cytotoxicity. A deep investigation on the effect of methyl (R)-9-hydroxystearate on HT29 cells showed an antiproliferative effect acting through the CDKN1A and MYCBP gene expression.
The reaction between bis(2-benzothiazolyl)ketone and vinyl Grignard reagents bearing different su... more The reaction between bis(2-benzothiazolyl)ketone and vinyl Grignard reagents bearing different substituents on the vinyl moiety gave the product derived from attack on the carbonylic carbon- and/or oxygen-atom. The regioselectivity of the attack depends on the kind of substituents bound to the vinylic carbon atoms and on their relative position. The reaction between vinylmagnesium bromide and 2-methyl-1-propenylmagnesium bromide was carried out under different experimental conditions and in the presence of radical scavengers. The results indicate a plausible mechanistic pathway involving radical intermediates in the case of-alkylation, but a polar ones in the case of classic-alkylation. This agrees with our previous reports indicating a key role played by the delocalization ability of the substituents bound to the carbonyl group in driving the regioselectivity of the vinylmagnesium bromide attack towards-alkylation. Further support of this was obtained by diffractometric analysis of...
Page 1. J. CHEM. RESEARCH (S), 2001 43 Recently, the Betti reaction2 has received renewed interes... more Page 1. J. CHEM. RESEARCH (S), 2001 43 Recently, the Betti reaction2 has received renewed interest3 and literature reports new investigations4 for synthetic chiral purposes.5 The original Betti reaction2 was performed using ...
ABSTRACT The reaction of a series of symmetric and unsymmetric triaminobenzene derivatives with p... more ABSTRACT The reaction of a series of symmetric and unsymmetric triaminobenzene derivatives with proton as electrophile has been studied. The formation of both Wheland complex (C-H salt) and N-H salt in relative amount depending on the experimental conditions has been observed. In the case of the attack of the proton on the nitrogen atom, the 1H and 13C NMR spectra showed the equivalence of three aromatic protons (and related carbon atoms) of the adduct thus indicating that salification occurs on a non-defined nitrogen atom. This behavior can be explained hypothesizing motion of the proton from a nitrogen atom to another in a motion that could not permit to define the protonation site. On the contrary, X-ray diffraction analysis on crystals of the NH salts reveals that in the solid state the proton is situated in a well-defined position.
Coupling reaction between aromatic electrophiles and nucleophiles: intermediates, products and an... more Coupling reaction between aromatic electrophiles and nucleophiles: intermediates, products and an unusual nitro group shift.
The first attempt to compare Boulton–Katritzky rearrangement with N-1/N-3-oxide tautomerism: form... more The first attempt to compare Boulton–Katritzky rearrangement with N-1/N-3-oxide tautomerism: formation of isomeric products in the reaction between 2-aminothiazoles and 7-chloro-4,6-dinitrobenzofuroxan.
Ruthenium complexes have proved to exhibit antineoplastic activity, related to the interaction of... more Ruthenium complexes have proved to exhibit antineoplastic activity, related to the interaction of the metal ion with DNA. In this context, synthetic and theoretical studies on ruthenium binding modes of thymine acetate (THAc) have been focused to shed light on the structure-activity relationship. This report deals with the reaction between dihydride ruthenium mer-[Ru(H)2(CO)(PPh3)3], 1 and the thymine acetic acid (THAcOH) selected as model for nucleobase derivatives. The reaction in refluxing toluene between 1 and THAcOH excess, by H2 release affords the double coordinating species κ1-(O)THAc-, κ2-(O,O)THAc-[Ru(CO)(PPh3)2], 2. The X-ray crystal structure confirms a simultaneous monohapto, dihapto- THAc coordination in a reciprocal facial disposition. Stepwise additions of THAcOH allowed to intercept the monohapto mer-κ1(O)THAc-Ru(CO)H(PPh3)3] 3 and dihapto trans(P,P)-κ2(O,O)THAc-[Ru(CO)H(PPh3)2] 4 species. Nuclear magnetic resonance (NMR) studies, associated with DFT (Density Functi...
The chiral (R)-10-hydroxystearic acid ((R)-10-HSA) is a positional homologue of both (R)-12-HSA a... more The chiral (R)-10-hydroxystearic acid ((R)-10-HSA) is a positional homologue of both (R)-12-HSA and (R)-9-HSA with the OH group in an intermediate position. While (R)-12-HSA is one of the best-known low-molecular-weight organogelators, (R)-9-HSA is not, but it forms crystals in several solvents. With the aim to gain information on the structural role of hydrogen-bonding interactions of the carbinol OH groups, we investigated the behavior of (R)-10-HSA in various solvents. This isomer displays an intermediate behavior between (R)-9 and (R)-12-HSA, producing a stable gel exclusively in paraffin oil, while it crystallizes in other organic solvents. Here, we report the X-ray structure of a single crystal of (R)-10-HSA as well as some structural information on its polymorphism, obtained through X-ray Powder Diffraction (XRPD) and Infrared Spectroscopy (IR). This case study provides new elements to elucidate the structural determinants of the microscopic architectures that lead to the for...
4,6-Dinitro-7-(thiazol-2-ylamino)benzo[c][1,2,5]oxadiazole 1-oxide was synthesized by a SNAr reac... more 4,6-Dinitro-7-(thiazol-2-ylamino)benzo[c][1,2,5]oxadiazole 1-oxide was synthesized by a SNAr reaction between 7-chloro-4,6-dinitrobenzofuroxan and 2-aminothiazole. The structure of the newly synthesized compound (45% yield) was elucidated based on 1H-NMR, 13C-NMR, NOESY-1D, ESI-MS, UV-Vis, and FT-IR techniques.
Ovarian cancer remains the leading cause of mortality among gynecological tumors. Estrogen recept... more Ovarian cancer remains the leading cause of mortality among gynecological tumors. Estrogen receptor beta (ERβ) expression has been suggested to act as a tumor suppressor in epithelial ovarian cancer by reducing both tumor growth and metastasis. ERβ expression abnormalities represent a critical step in the development and progression of ovarian cancer: for these reasons, its re-expression by genetic engineering, as well as the use of targeted ERβ therapies, still constitute an important therapeutic approach. 3-{[2-chloro-1-(4-chlorobenzyl)-5-methoxy-6-methyl-1H-indol-3-yl]methylene}-5-hydroxy-6-methyl-1,3-dihydro-2H-indol-2-one, referred to here as compound 3, has been shown to have cytostatic as well cytotoxic effects on various hormone-dependent cancer cell lines. However, the mechanism of its anti-carcinogenic activity is not well understood. Here, we offer a possible explanation of such an effect in the human ovarian cancer cell line IGROV1. Chromatin binding protein assay and li...
The compound 1,1’,1’’-(2’,4’-dinitro-[1,1’-biphenyl]-2,4,6-triyl)tripiperidine was synthesized by... more The compound 1,1’,1’’-(2’,4’-dinitro-[1,1’-biphenyl]-2,4,6-triyl)tripiperidine was synthesized by SEAr/SNAr reaction between 1-fluoro-2,4-dinitrobenzene and 1,3,5-tris(N-piperidinyl)benzene. The structure of the newly synthesized compound was elucidated based on 1H-NMR, 13C-NMR, ESI-MS, UV-Vis and IR spectroscopy.
3,5-Dimethoxy-2-[(4-methoxyphenyl)diazenyl]phenol was synthesized by an azo-coupling reaction bet... more 3,5-Dimethoxy-2-[(4-methoxyphenyl)diazenyl]phenol was synthesized by an azo-coupling reaction between 3,5-dimethoxyphenol and 4-methoxy benzenediazonium tetrafluoroborate. The structure of newly synthesized compound was elucidated based on 1H NMR, 13C NMR, ESI-MS, UV-Vis and FT-IR.
The fight against cancer is one of the most challenging tasks currently for lots of researchers i... more The fight against cancer is one of the most challenging tasks currently for lots of researchers in many fields, such as pharmaceuticals, medicine, and chemicals [...]
9-Hydroxystearic acid (9-HSA) is an endogenous cellular lipid that possesses antiproliferative an... more 9-Hydroxystearic acid (9-HSA) is an endogenous cellular lipid that possesses antiproliferative and selective effects against cancer cells. A series of derivatives were synthesized in order to investigate the effect of the substituent in position 9 and on the methyl ester functionality on the biological activity. The two separate enantiomers of methyl 9-hydroxystearate and of methyl 9-aminostearate showed antiproliferative activity against the HT29 cell line. This indicates the importance of position 9 groups being able to make hydrogen bonding with the molecular target. Further, this effect must be preserved when the carboxy group of 9-HSA is esterified. The biological tests showed that the amines, contrarily to methyl esters, resulted in cytotoxicity. A deep investigation on the effect of methyl (R)-9-hydroxystearate on HT29 cells showed an antiproliferative effect acting through the CDKN1A and MYCBP gene expression.
The reaction between bis(2-benzothiazolyl)ketone and vinyl Grignard reagents bearing different su... more The reaction between bis(2-benzothiazolyl)ketone and vinyl Grignard reagents bearing different substituents on the vinyl moiety gave the product derived from attack on the carbonylic carbon- and/or oxygen-atom. The regioselectivity of the attack depends on the kind of substituents bound to the vinylic carbon atoms and on their relative position. The reaction between vinylmagnesium bromide and 2-methyl-1-propenylmagnesium bromide was carried out under different experimental conditions and in the presence of radical scavengers. The results indicate a plausible mechanistic pathway involving radical intermediates in the case of-alkylation, but a polar ones in the case of classic-alkylation. This agrees with our previous reports indicating a key role played by the delocalization ability of the substituents bound to the carbonyl group in driving the regioselectivity of the vinylmagnesium bromide attack towards-alkylation. Further support of this was obtained by diffractometric analysis of...
Page 1. J. CHEM. RESEARCH (S), 2001 43 Recently, the Betti reaction2 has received renewed interes... more Page 1. J. CHEM. RESEARCH (S), 2001 43 Recently, the Betti reaction2 has received renewed interest3 and literature reports new investigations4 for synthetic chiral purposes.5 The original Betti reaction2 was performed using ...
ABSTRACT The reaction of a series of symmetric and unsymmetric triaminobenzene derivatives with p... more ABSTRACT The reaction of a series of symmetric and unsymmetric triaminobenzene derivatives with proton as electrophile has been studied. The formation of both Wheland complex (C-H salt) and N-H salt in relative amount depending on the experimental conditions has been observed. In the case of the attack of the proton on the nitrogen atom, the 1H and 13C NMR spectra showed the equivalence of three aromatic protons (and related carbon atoms) of the adduct thus indicating that salification occurs on a non-defined nitrogen atom. This behavior can be explained hypothesizing motion of the proton from a nitrogen atom to another in a motion that could not permit to define the protonation site. On the contrary, X-ray diffraction analysis on crystals of the NH salts reveals that in the solid state the proton is situated in a well-defined position.
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