First insights into the synthesis of carbo-phospholane and carbo-phospholene oxides

Fifteen-membered ring carbo-mers of five-membered rings are considered in the heterocyclic series of the phosphole oxide and less unsaturated parents. The synthesis of the first carbo-phospholane oxides is achieved by a [14+1] two-step/one-pot macrocyclization route with 86 % yield. Reduction of the latter phosphora-[5]pericyclyne with SnCl­2 allowed consistent 1H and 31P NMR characterization of the corresponding carbo-phospholene, produced with 11 % yield. The ultimate carbo-phosphole oxide could not be isolated, but preliminary results on alternative strategies towards this 14 pz-electron Hückel carbo-aromatic are reported.

Towards fluorescent indolyl-carbo-benzenes

The C18 macro-aromatic carbo-benzene core is a strong chromophoric unit resembling the porphine ring which is prone to quench the emission of fluorophoric substituents. Within the aim of preparing fluorescent carbo-benzenes (and carbo-cyclohexadiene parents) for measurement of their two-photon absorption cross-section by the TPEF method, several indole derivatives were devised and anchored to the C18 macrocycle either directly, p-phenylogously or ethynylogously. Synthesis methodology and spectroscopical measurements are presented in a comparative prospec

First example of ring carbomer of 1,4-cyclohexadiene

While a series of carbo-mers of 1,3-cyclohexadienes was reported through the use of a specifically developed synthetic strategy, no example of their 1,4-regioisomers was known. Inspired by the methodology elaborated for the preparation of the 1,3-isomers, the synthesis of the first example of carbo-mer of 1,4-cyclohexadiene is presented. Comparison of physico-chemical properties of this first representative with those of the recently described 1,4-regioisomer, especially UV-vis absorption properties, is also addressed

En route to a dianilinyl-substituted carbo-cyclohexadiene with promising electrical properties

The macro-aromatic carbo-benzene core para-disubstituted by 4-anilinyl groups is known to be an efficient single-molecule conductor, exhibiting a conductance of 106 nS measured by the scanning tunneling microscopy-break junction technique. The linear carbo-butadiene analogue bearing the same anilinyl substituents was found to be less efficient, with a conductance of 2.7 nS. The reason of this difference could be elucidated through the study of the charge transport properties of a cyclically locked carbo-butadiene core in a carbo-cyclohexadiene derivative. In this paper, advances in the synthesis of this challenging dianilinyl-substituted carbo-cyclohexadiene are presented

A difluorenyl-carbo-cyclohexadiene: prospective chromophore for two-photon absorption

For the purpose of outlining structure-property relationships for two-photon absorption (2PA), a "s-locked" carbo-cyclohexadiene with two fluorenyl substituents has been envisaged for comparison with previously studied aromatic carbo-benzene and non-aromatic carbo-quinoid congeners. A representative where the C10-π-conjugated fluorenyl moieties are also connected by a C8-π-insulating 3,6‐dimethoxy‐3,6‐bis(trifluoromethyl)octa‐1,4,7‐triyn-1,8-diyl edge has thus been synthesized in four steps from known C8F triyne and C10 triynyldial, through a [8F+10] cyclization process. In spite of a relatively strong absorbance (e = 84 800 L.mol-1.cm-1 at 634 nm), the non-vanishing green fluorescence (at 533 nm) of the chromophore should allow measurements of the 2PA cross section by both the TPEF and Z-scan methods

Fluorinated analogues of lipidic dialkynylcarbinol pharmacophores: synthesis and cytotoxicity in HCT116 cancer cells

Lipidic alkynylcarbinols (LACs) have been identified as potential antitumor compounds, and a thorough understanding of their pharmacophoric environment is now required to elucidate their biological mode of action. In the dialkynylcarbinol (DAC) series, a specific study of the pharmacophore potential has been undertaken by focusing on the synthesis of three fluorinated derivatives followed by their biological evaluation. This work highlights the requirement of an electron-rich secondary carbinol center as a key structure for cytotoxicity in HCT116 cells

Ethynylogation approach in antitumor lipid pharmacochemistry: from dialkynyl-carbinols to trialkynyl-carbinols

A recently proposed "ethynylogation" pharmacochemical approach, first envisaged in the series of anticancer lipidic dialkynylcarbinols (DACs) H–C≡C–CH(OH)–C≡C–R at the levels of the H–C⋮ and ⋮C–R bonds for R = n-C12H25, is completed here at the level of the (HO)C–H bond. The so-devised mono-lipidic trialkynylcarbinol (TAC) target (HC≡C)2C(OH)–C≡CR and its bis-lipidic counterpart HC≡C–C(OH)(C≡CR)2 were synthesized in 4 steps and with 33 % and 23 % overall yield, respectively. Their antitumor cytotoxicity has been evaluated towards HCT116 cells: while the latter TAC is totally inactive, the former DAC-ethynylogous TAC still exhibits a significant toxicity with an IC50 of 10 µM

On terminal alkynylcarbinols and derivatization thereof

The chemistry of three prototypes of secondary alkynylcarbinols (ACs), recently highlighted as challenging targets in anti-tumoral medicinal chemistry, is further documented by results on n-alkyl, alkynyl and alkenyl representatives. The N-naphthyl carbamate of an n-butyl-AC is thus characterized by X-ray crystallography. A novel dialkynylcarbinol (DAC) with synthetic potential is described, namely the highly dissymmetrical triisopropylsilyl-protected version of diethynylmethanol. The latter is shown to act as a dipolarophile in a selective Huisgen reaction with benzyl azide under CuAAC click conditions, giving an alkenyl-AC, where the alkene unsaturation is embedded in a 1,4-disubstituted 1,2,3-triazole ring, as confirmed by X-ray crystallography.Supplementary information (CIF file

Синтез 1-(триетилсиліл)-3-[4-(гетарил)феніл]- 5-(триметилсиліл)пента-1,4-діїн-3-олів

The method of synthesis of 1-(triethylsilyl)-3-[4-(hetaryl)phenyl]-5-(trimethylsilyl)penta-1,4-diyn-3-ols based on the interaction between 1-(triethylsilyl)-5-(trimethylsilyl)penta-1,4-diyn-3-one and lithium derivatives of 1-(4-bromophenyl)-1H-indole or 9-(4-bromophenyl)-9H-carbazole has been developed.Разработан метод синтеза 1-(триэтилсилил)-3-[4-(гетарил)фенил]-5-(триметилсилил)пента-1,4-диин-3-олов, основанный на взаимодействии литиевых производных 1-(4-бромфенил)-1Н-индола и 9-(4-бромфенил)-9Н-карбазола с 1-(триэтилсилил)-5-(триметилсилил)пента-1,4-диин-3-оном.Розроблено метод синтезу 1-(триетилсиліл)-3-[4-(гетарил)феніл]-5-(триметилсиліл)пента-1,4-діїн-3-олів, що базується на взаємодії літієвих похідних 1-(4-бромофеніл)-1Н-індолу та 9-(4-бромофеніл)-9Н-карбазолу з 1-(триетилсиліл)-5-(триметилсиліл)пента-1,4-діїн-3-оном