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Abstract: Addition of diethylphosphite to cyclic α-perfluoalkyl substituted imines in the presence of boron trifluoride etherate as a catalyst presents an efficient route for racemic saturated cyclic α-perfluoroalkyl-α-aminophosphonates. Hydrolysis of latter compounds gives the corresponding α-aminoalkanephosphonic acids existing as the corresponding zwitterions according IR and X-ray data. [Copyright &y& Elsevier]

Abstract: Water as a solvent significantly accelerates the addition of various amines to diethyl vinylphosphonate to yield β-aminophosphonates without any catalyst compared to known procedures for such aza-Michael reactions. The products are obtained in quantitative yields and high purity over short reaction times. Using a reactant ratio (vinylphosphonate/amine) of 2:1 resulted in double phosphorylation of primary amines. [Copyright &y& Elsevier]

Abstract: Application of water as a sole solvent promotes the aza-Michael reaction of diethyl vinylphosphonate and diphenylvinylphosphine oxide with α-substituted amino acid sodium salts generated in situ to afford the corresponding β-aminophosphonates and β-aminophosphine oxides in excellent yields and of high purity. The approach is equally suitable for the synthesis of both racemic and optically active compounds. In the case of glycine, the mono and bis(phosphonoethyl)-substituted products are formed in 6:4 ratio and when using a stoichiometric amount of the reactants, N,N-bis[2-(diethoxyphosphoryl)ethyl]glycine was the only product. In contrast, to perform the double phosphonoethylation of d,l-alanine, prolonged heating of the reaction mixture was required. [Copyright &y& Elsevier]

Abstract: In order to give further insight on the influence of the aromatic ring nature and the presence of the phosphorus substituent at the piperidone nitrogen atom of E,E-3,5-bis((hetero)arylidene)piperid-4-ones on their antitumor properties, a series of phosphorus substituted E,E-3,5-bis(pyridinylmethylene)piperid-4-ones bearing either 3-pyridine or 4-pyridine rings was obtained. Novel NH-3,5-bis(pyridinylmethylene)piperid-4-ones 1a,b were converted into the corresponding N-phosphorylated derivatives 3a–c, 4a–c differing in the substitution at the phosphorus atom (amidophosphates and amidophosphonates), via direct phosphorylation while N-(ω-phosphorylalkyl)-substituted compounds 8a–c were obtained via aldol-crotonic condensation of preformed N-phosphorylalkyl substituted piperidones with the corresponding pyridinecarboxaldehyde. The cytotoxicity screen has revealed that phosphorylated compounds based on E,E-3,5-bis(4-pyridinylmethylene)piperid-4-one framework displayed higher inhibitory properties toward Caov3, A549, KB 3-1 and KB 8-5 human carcinoma cell lines comparing with their analogues with 3-pyridine rings. Introduction of the phosphorus moiety substantially increased the antitumor properties in the case of E,E-3,5-bis(3-pyridinylmethylene)piperid-4-ones derivatives but this influence less pronounced for more active analogues bearing 4-pyridinyl rings. Most of the compounds tested are potent against multi-drug resistant cell line KB 8-5 affording some guidelines for the search of perspective drug-candidates among phosphorus substituted E,E-3,5-bis((hetero)arylidene)piperid-4-ones. [ABSTRACT FROM AUTHOR]

Abstract: In order to design the agents with improved antitumor activity of 3,5-bis(thienylidene)piperid-4-one type, E,E-N-phosphoryl-3,5-bis(thienylidene)piperid-4-ones 6a-c and E,E-N-ω-phosphorylalkyl-3,5-bis-(thienylidene)piperid-4-ones 7a-c were obtained via the direct phosphorylation of the parent NH-3,5-bis(thienylidene)piperid-4-one and by condensation of preformed N-phosphorylalkyl substituted piperidones with thiophene 2-carbaldehyde, respectively. The structures of the compounds were elucidated by 1H, 31P, 13C NMR along with a single crystal X-ray diffraction analysis. Under the action of visible light thermodynamically more stable E,E-isomers slowly undergo photochemical conversion in CDCl3 solution to the corresponding E,Z-isomers and E,Z-N-methyl-3,5-bis(thienylidene)piperid-4-one 5 was isolated in individual state. The importance of phosphorylation for cytotoxic properties of 3,5-bis(thienylidene)piperid-4-ones towards human carcinoma cell lines Caov3, Scov3, and A549 and influence of olefin configuration on antitumor activity were demonstrated. [Copyright &y& Elsevier]

Abstract: A convenient method for the preparation of α-CF3-α-aminophosphonates bearing alkynyl group at the α-carbon atom has been described. New alkynylphosphonates have been further utilized in the synthesis of functionalized triazole-containing α-CF3-α-aminophosphonates via copper-catalyzed (3+2)-cycloaddition to different organic azides. [Copyright &y& Elsevier]

Abstract: A series of E,E-N-phosphorylalkylene-3,5-bis(arylidene)piperid-4-ones 7a–k was prepared via the condensation of aromatic aldehydes with ω-aminophosphonates 5a–c and 6a,b bearing piperidone or a protected piperidone moiety, respectively. The synthetic routes to the starting aminophosphonates 5a–c and 6a,b varied depending on the number of methylene groups in the alkylene chain and comprised the Kabachnik–Fields reaction (n =1), the aza-Michael reaction (n =2) or alkylation of 4-piperidone hydrochloride with diethyl ω-bromoalkylphosphonates under phase transfer catalysis conditions (n =3,4). Phosphoryl substituted 3,5-bis(arylidene)piperid-4-ones 7b,c,e,f,h,i,k bearing both nitro groups and fluorine atoms in the para-position of the arene rings possess cytotoxicity toward human carcinoma cell lines CaOv3, Scov3, PC3 and A549 in the low micromolar range while their analogues having para-dimethylamino groups had IC50 values greater than 50μM. In contrast, only Me2N-substituted phosphonates 7g,j (n =3 and 4) and the salts of Me2N-substituted phosphonic acids 10c,f (n =2 and 3) display fluorescence. [Copyright &y& Elsevier]

Abstract: A convenient access to carbamoylmethylphosphine oxides (CMPO) in up to 96% isolated yield is developed via direct amidation of diphenylphosphoryl acetic acid in an ionic liquid as a recyclable reaction medium in the presence of triphenyl phosphite. The influence of the nature of the amine and anion and cation structure in the ionic liquid on the reaction rate and yields of the products are also investigated. 1-Butyl-3-methylimidazolium bromide [bmim]Br and trihexyltetradecylphosphonium chloride [P(C6H13)3(C14H29)]Cl proved to be the best media for carrying out this reaction. [Copyright &y& Elsevier]