Phenylalanine derivatives containing acyl groups of stereoisomeric N-[tetramethyldiamido(thio)phosphoryl]-and N- [dimorpholido(thio)phosphoryl]-4-aminocyclohexane-carboxylic acids

Conclusions The ethyl esters and Na salts of N-(tetramethyldiamldo(thio)phosphoryl)- and N-(dimorpholido(thio)phosphoryl)-cis- and trans-4-ACHC-DL-phenylalanine have been synthesized.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 386–390, February, 1980.     

Electrochemical Properties of Crown-Containing N-(Thio)phosphoryl(thio)ureas and Their Complexes with 3d Transition Metals

The electrochemical behavior of crown-containing N-(thio)phosphoryl(thio)ureas and their complexes with 3d transition metals was studied by dc voltammetry on a graphite electrode in acetone. Crown-containing N-(thio)phosphoryl(thio)ureas are not reduced but are oxidized on solid electrodes in the examined range of potentials; the electrons are transferred via the (thio)urea group. Electrooxidation of macrocyclic Co(II), Ni(II), and Cu(II) complexes probably occurs via formation of M(III) complex species. Electroreduction of these metal complexes involves stepwise electron transfer, with the oxidation state of the metal atom decreasing to 0, followed by dissociation of the electrochemical reaction products.     

Distinct chemoselectivity in the reaction of N-(thio)phosphoryl imines with diethylzinc

This report describes the reaction of N-(thio)phosphoryl imines with diethylzinc under different conditions. An interesting and distinct chemoselectivity between hydrogen-addition and ethyl-addition to imine double bond is disclosed: in weakly polar solvent, e.g. toluene, N-(thio)phosphoryl imines were exclusively reduced in excellent yields via a β-H transfer from diethylzinc to imine double bond; in polar solvents like THF, the reduction product was competitively formed as a major product together with the minor product resulting from ethyl-addition to imine double bond; in sharp contrast, in the presence of strong coordinative additive N,N,N′,N′-tetramethylethylenediamine (TMEDA), the ethylation product was formed exclusively from the reaction of N-(thio)phosphoryl imine with diethylzinc. These results are discussed and explained in terms of the coordination interactions between the imine, solvent, and additive with diethylzinc.     

Structure and molecular lability of N-(thio)phosphoryl(thio)amides: XVII. Intramolecular transformations of N,N′-bis(thio)phosphoryl(thio)ureas with the open-chain fragment in DMSO solution

By means of the ¹H, ¹³C, and ³¹P NMR spectroscopy structure and intramolecular transformations of N,N′-bis[diisopropoxythiophosphorylaminothiocarbonyl]-1,7-diaminoheptane in 3–10% DMSO solutions were studied. High lability of molecule with the realization of two conformers (linear and pincer-like) of macromolecule, of the proton imide-imide exchange, and of different tautomeric forms was proved.     

Nucleophilic phosphine-catalyzed [3+2] cycloaddition of allenes with N-(thio)phosphoryl imines and acidic methanolysis of adducts N-(thio)phosphoryl 3-pyrrolines: a facile synthesis of free amine 3-pyrrolines

In this report, the dipolarophile imines with easily removable activating group O,O-diethyl(thio)phosphoryl have been investigated in the nucleophilic phosphine-catalyzed [3+2] cycloaddition reaction of electron-deficient allenes. Under the catalysis of a tertiary phosphine, N-(thio)phosphorylimines readily undergo the [3+2] cycloaddition reaction with ethyl 2,3-butadienoate or ethyl 2,3-pentadienoate, affording the corresponding N-(thio)phosphoryl 3-pyrrolines in moderate to high yields with good diastereoselectivity. Removal of the (thio)phosphoryl group from the adducts has been successfully achieved via the acidic methanolysis of the P-N bond, giving the free amine 3-pyrrolines in fair to good yields without severe aromatization. Thus, a facile synthesis of N-unsubstituted 3-pyrrolines is established from the phosphine-catalyzed [3+2] cycloaddition reaction of allenes with imines.     

Unique charge-separated intermolecular and eight-membered intramolecular H-bonds in bis-(thio)barbiturates

Reaction of symmetrical and unsymmetrical (thio)barbituric acids with aldehydes in the presence of triethylamine afforded a new form of bis-(thio)barbiturate containing charge-separated inter- and eight-membered intramolecular H-bonds. The reaction products were obtained as bis-(thio)barbiturates containing eight-membered intramolecular H-bond in the presence of l-(+)-tartaric acid (TA). The intramolecular H-bond strength (kcal/mol) and corresponding pKa value for 4ab′ were estimated to be 37 kcal/mol and ?1.3, respectively.     

Ammonium-chlor(thio)phosphat-Betaine,eine Klasse koordinationsstabilisierter Chlor(thio)metaphosphate

Ammonium Chloro(thio)phosphate Betaines, a Class of Coordination-stabilized Chloro(thio)metaphosphates Ammonium chloro(thio)phosphate betaines behave like systems being in equilibrium with tert. amine and monomeric chloro(thio)metaphosphate. In solution at room temperature the amine component can be displaced by stronger donors. Mass spectra reveal the presence of ClPS₂ as monomer and dimer, of ClPO₂ by fragment ions of the dimer, trimer, and tetramer before reorganization takes place to form PXCl₃ and P₄X₁₀ (X = O, S). Detection of ClPOS fails owing to fast equilibration into ClPO₂ and ClPS₂.     

New approach to preparation of N-acylphosphoramido(thio)(seleno)ates

N-[2-(X)-1,3,2-Oxathiaphospholane] derivatives (X = S, Se, O) of carboxamides were prepared and their DBU-assisted reaction with alcohols led to the corresponding O-alkyl-N-acylphosphoramido(thio)(seleno)ates. Their structures were confirmed by MS analysis and ¹H and ³¹P NMR spectroscopy. Independently N-acylphosphoramidoselenoates were converted to N-acylphosphoramidates by treatment with tert-butylperoxytrimethylsilane. The oxathiaphospholane approach was also applied to the synthesis of derivatives having N-prolylphosphoramido(thio)(seleno)ate linkages on the 5′-OH group of AMP.     

Ab initio calculations of effect of (thio)xanthenyl and dibenzosuberenyl substituents on dehydrogenation of N-Benzylanilines

Higher values of the energies of the highest occupied molecular orbitals for N-benzyl-4-[9-(thio)-xanthenyl]aniline, N-benzyl-4-(5-dibenzosuberenyl)aniline molecules and their zwitterions and the electron density increase on the reaction center (carbon atom in the CH₂-group) for the latter were obtained in the quantum-chemical calculations by RHF/6-31G(d) method. This explains the possibility and the ease of dehydrogenation of N-benzyl-4-[9-(thio)xanthenyl]aniline with imines in trifluoroacetic acid due to effect of the substituents. The calculated data suggest the same possibility for N-benzyl-4-(5-dibenzosuberenyl)aniline: it is dehydrogenated already in the synthesis from N-benzylaniline and dibenzosuberenol in acetic acid.     

Magnetic properties of stable N-[(dichlorophenyl)thio]-2,4,6-triphenylphenylaminyl and N-[(dichlorophenyl)thio]-2,4,6-tris(chlorophenyl)phenylaminyl radical crystals

The magnetic properties of N-[(dichlorophenyl)thio]-2,4,6-triarylphenylaminyl radical crystals are reported. The three stable thioaminyls show ferromagnetic behaviors described using the one-dimensional Heisenberg model with the large ferromagnetic interaction of 2J/k_B = 28.0, 11.4, and 3.6 K. The other two radicals show the antiferromagnetic alternating chain behaviors with 2J/k_B = −16.8 K, = 0.55 and 2J/k_B = −128.8 K, = 0.90. The low-temperature susceptibility and heat capacity measurements of the crystal showing 2J/k_B = 28.0 K reveal a magnetic phase transition at 0.4 K. The ordered phase shows spin-flop transition which reveals an antiferromagnetic long range order.     

Reaction of chloromethyliso(thio)cyanato(thio)phosphonates(-phosphinates) with phenol,ethanol, and thiols

(Chloromethyl)isocyanatophosphonates(-phosphinates) take up phenol to form carbamates whose -cleavage gives rise to phenyl (chloromethyl)phosphonates(-phosphinates). (Chloromethyl)(thio)phosphinic-(phosphonic) isothiocyanates react with phenol at 20°C in the absence of catalyst to afford phenyl phosphinates(-phosphonates). (Alkylsulfanyl)carbamates formed by addition of thiols to (chloromethyl)iso(thio)cyanastophosphonates(-phosphinates) under the action of an equimolar amount of triethylamine undergo cyclization into 1,3,4-oxaza(thiaza)phospholines.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 9, 2004, pp. 1441–1446.Original Russian Text Copyright © 2004 by Khailova, Bagautdinova, Shaimardanova, Krepysheva, M. Pudovik, Chmutova, Azancheev, Musin, A. Pudovik.This revised version was published online in April 2005 with a corrected cover date.     

Reductive allylation of 1H-pyridine-2-(thio)ones by means of the novel lithium allyldibutylmagnesate reagent

A new, highly efficient allylation reagent—lithium allyldibutylmagnesate (allylBu₂MgLi)—was obtained by mixing allyl-magnesium chloride (1 equiv) and n-BuLi (2 equiv). N-Lithiated and N-methyl substituted 1H-pyridine-2-thiones and -ones were successfully and regioselectively allylated by treatment with allylBu₂MgLi yielding 6-allyl-3,6-dihydro-1H-pyridine-2-(thio)ones and 4-allyl-3,4-di-hydro-1H-pyridine-2-(thio)ones. The latter were formed by a 3,3-sigmatropic Cope rearrangement of the former.     

Chiral enantiopure bis(thio)ureas derived from TADDOL and their carboxylate complexation capacity

New chiral enantiopure ureas and thioureas with (R,R)-TADDOL backbone were synthesized. Bis-(thio)ureas with C2 symmetry were obtained from TADDOL iso(thio)cyanates and bifunctional amino-(thio)ureas from TADDAMINE, respectively. These were tested for carboxylate recognition capacity and the association constant was determined for the most stable complex.      

Silicon-(thio)urea Lewis acid catalysis

We present a new class of catalysts based on the combination of N,N'-diaryl(thio)ureas and weak silicon Lewis acids (e.g., SiCl(4)). Such silicon-(thio)urea catalysts effectively catalyze the stereospecific rearrangement of epoxides to quaternary carbaldehydes.     

The interplay of thio(seleno)amide/vinylogous thio(seleno)amide "resonance" and the anisotropic effect of thiocarbonyl and selenocarbonyl functional groups

Amino-substituted thio(seleno)acrylamides 1-4 were synthesized and their 1H and 13C NMR spectra assigned. Both the NMR data and the results of theoretical calculations at the ab initio level of theory were employed to elucidate the adopted structures of the compounds in terms of E/Z isomerism and s-cis/s-trans configuration. In the case of the asymmetrically N(Me)Ph-substituted compounds, ab initio GIAO-calculated ring current effects of the N-phenyl group were applied to successfully determine the preferred conformer bias. The restricted rotations about the two C-N partial double bonds were studied by DNMR and the barriers to rotation (DeltaG(c)++) determined at the coalescence temperatures, and these were discussed with respect to the structural differences between the compounds. The barriers to rotation were also calculated at the ab initio level of theory where the best results (R(2) = 0.8746) were obtained only with inclusion of the solvent at the SCIPCM-HF/6-31G* level of theory. The calculations also provided means of assessing structural influences which were not available due to inaccessible rotation barriers. By means of natural bond orbital (NBO) analysis of 1-4, the occupation numbers of nitrogen lone pairs and bonding/antibonding pi/pi orbitals were shown to quantitatively describe thio(seleno)amide/vinylogous thio(seleno)amide "resonance". Finally, the thio(seleno)carbonyl anisotropic effect was quantitatively calculated by the GIAO method and visualized by isochemical shielding surfaces (ICSS). Only marginal differences between the two anisotropic effects were calculated and are therefore of questionable utility for previous and future applications with respect to stereochemical assignments.     

Reactions of N-phenylamide and phenyl (thio)esters of 3-phenylpropiolic acid with benzene under superelectrophilic activation

N-Phenylamide and phenyl (thio)esters of 3-phenylpropiolic acid add benzene in the presence of CF₃SO₃H or AlX₃ (X = Cl, Br) to give 4,4-diphenyl-3,4-dihydroquinolin-2-one, 4,4-diphenyl-3,4-dihydrocoumarin, and 4,4-diphenyl-3,4-dihydrothiocoumarin, respectively.     

苯并(硫)吡喃-4-酮衍生物的合成与表征

以取代或未取代苯并(硫)吡喃-4-酮(1a～1c)为原料, 分别与呋喃甲醛和6-氨基胡椒醛发生缩合反应合成了一系列的取代或未取代苯并(硫)吡喃衍生物2a～2c和3a～3c, 化合物2a～2c和3a～3c的结构经IR, ¹H NMR, MS和元素分析进行鉴定和表征.     

Crown-Containing N-(Thio)Phosphoryl-(Thio)Ureas,their Ligand Properties and Analytical Application

Abstract

Crown-containing N-(thio)phosphoryl(thio)ureas are related to a class of NH-acids due to the presence of two acceptor-groups: (thio)phosphorylic and (thio)acylic. In agreement with structure of lariat ether, it was observed a stage corresponding to the step ejection of two H* ion on the potentiometric titration curve of ligand by alkaline. Calculated step ionization constants demonstrate that these compounds are weak acids with relative values of pK₁ and pK₂.     

Design and synthesis of novel indoline-(thio)urea hybrids

Abstract

A series of novel indoline-(thio)urea were designed and prepared using indoline(s) as a new platform and tested as organocatalysts in the Michael and Morita–Baylis–Hillman reactions. Most of the compounds were found to be very active catalysts although they did not promote the enantioselectivity. As agents for the conversion of thiocarbonyl compounds into carbonyl compounds, potentials of PIFA and DDQ were also displayed. Furthermore, DFT calculations rationalized the experimentally observed non-enantioselectivity of the catalysts.     

Reaction of (chloromethyl)phosphonic(-phosphinic) iso(thio)cyanates with alcohols and (α-hydroxyalkyl)phosphonates

Alcohols and α-hydroxyphosphonates undergo the addition to (chloromethyl)phosphonic(-phosphinic) iso(thio)cyanates, yielding phosphorylated (thio)urethanes. The latter undergo cyclization to form, depending on their structure, saturated or unsaturated five-membered P,N,O,S-containing heterocycles.