N-phenyl Derivatives Research Articles

Synthesis of N-Alkylated and N-Arylated Derivatives of 2-Amino-2‘-hydroxy-1,1‘-binaphthyl (NOBIN) and 2,2‘-Diamino-1,1‘-binaphthyl and Their Application in the Enantioselective Addition of Diethylzinc to Aromatic Aldehydes

High-yield reductive alkylation of (R)-(+)-1 and (R)-(+)-2 has been accomplished with a series of ketones (even as bulky as 2-adamantanone) and NaBH4/H2SO4 in THF at room temperature to give the respective N-alkylated binaphthyls 6a−c, 9a−c, and 10a−c. Related N-phenyl derivatives 14, 16, and 17 were obtained via the Pd(0)-catalyzed coupling of (R)-(+)-1 and (R)-(+)-2, respectively, with PhBr; no racemization was observed. Subsequent reductive methylation with CH2O and NaBH4/H2SO4 afforded the bidentate ligands 8a−c, 12a−c, 13a−c, 15, 18, and 19, which comprise a new class of binaphthyls. Their utility as chiral ligands has been demonstrated for the addition of Et2Zn to benzaldehyde and its congeners; the highest level of asymmetric induction was observed for N,N-dimethyl NOBIN (R)-(+)-3 (3 mol %) in conjunction with n-BuLi (5.4 mol %), which gave (R)-(+)-21a in 88% ee. Derivatives of the amino phenol 1 (NOBIN) proved more efficient than the corresponding diamines derived from 2. The stereochemical outcome and the enhancement of asymmetric induction by Li+ are discussed in terms of the chelated transition state 26.

Investigations on the synthesis and properties of N-phenyl derivatives of 1,4-dioxo(1,4,5-trioxo)-1,2,3,4-tetra(1,2,3,4,5,6-hexa)hydropyrido-[3,4-d]pyridazines and allied compounds

2-(1-Piperidino)- and 2-(4-methyl-1-piperazinyl)-6-methyl-3,4-pyridinedicarboximides (1, 2) react with N-phenylhydrazine yielding N-phenylamino-3,4-pyridinedicarboximides (7, 8). The same reaction with 1,6-dimethyl-2-oxo-1,2-dihydro- and 2-chloro-6-methyl-3,4-pyridinedicarboximides (3, 17) gives the salts of the corresponding N-phenylpyridopyridazines with phenylhydrazine (13, 18), which transform into N-phenylaminoimides (14,19) during boiling in 80% acetic acid. Compounds 7, 8 and 14 isomerize to the corresponding 2-phenyl-1,4-dioxo(1,4,5-trioxo)-1,2,3,4-tetra(1,2,3,4,5,6-hexa)hydropyrido[3,4-d]pyridazines (9,10, 15) under the influence of heating in alcoholic solution of C2H5ONa or CH3ONa. Only in the case of imide 19 are 2- and 3-phenyl isomers (20 and 21) formed under these conditions. Some of the obtained compounds were pharmacologically active.

Imido/nitrene ligands in the complexes of platinum metals

A synthetic search for palladium and platinum complexes with nitrene ligands via reaction of tetranuclear cluster Pd 4( μ 2-CO) 4( μ 2-OAc) 4 with nitrosobenzene and reactions of mononuclear complexes [MX 4] 2− (M=Pt, Pd; X=Cl, NO 2) with o-phenylenediamine and its N-phenyl derivative have been carried out. The complexes obtained, [Pd(OAc) o-(PhN)(NO)C 6H 4] 2, Pd[ o-(NPh)(N)C 6H 4] 2, Pt[ o-(NPh)(N)C 6H 4] 2, Pt 2[ o-(NPh)(N)C 6H 4] 4[O 3SCF 3] 2, and Pt 2[ o-(NPh)(N)C 6H 4] 4Br 2, have been structurally characterized by single crystal X-ray diffraction studies. The oxidation of complex Pt[ o-(NPh)(N)C 6H 4] 2 by excess AgO 3SCF 3 afforded a heterotricyclic quinoxaline derivative, whose structure has been determined by X-ray analysis. The data obtained suggest that labile nitrene species coordinated to Pd and Pt complexes are possible intermediates in the reactions under study.

Synthesis of a novel pseudodisaccharide glycoside as a potential glycosidase inhibitor

An N-linked pseudodisaccharide 2 containing an inositol moiety in place of a glycopyranosyl residue has been synthesised to mimic the disaccharide unit, 3-O-(α-D-glucopyranosyl)-D-glucopyranose, cleaved by Glucosidase II during glycoprotein processing; an attempt to prepare the analogous 2-N-linked compound 1 as an inhibitor of Glucosidase I led to the novel N-phenyl derivative 10 of 2-amino-2-deoxy-D-glucopyranose.

Synthesis and Antifungal Activity of 2-Hydroxy-1-naphthalaniline and its N-Phenyl Derivatives

Synthesis and Antifungal Activity of 2-Hydroxy-1-naphthalaniline and its N-Phenyl Derivatives

Rate and equilibrium constants for oxazolidine and thiazolidine ring-opening reactions

Abstract

Comprehensive Model of the Photophysics of N-Phenylnaphthalimides: The Role of Solvent and Rotational Relaxation

Absorption and fluorescence spectra, fluorescence decay times, and quantum yields of fluorescence and triplet state formation have been determined for N-phenyl and substituted N-phenyl derivatives of 1,2-, 2,3-, and 1,8-naphthalimides, using stationary irradiation and laser flash excitation methods. The effects of substituents on the N-phenyl group on solvent polarity and viscosity have been studied. A short-wavelength (SW) fluorescence, similar to the luminescence emitted by the N-alkyl derivatives, and/or a considerably red shifted long-wavelength (LW) luminescence are observed, and the ratio of the SW and LW fluorescence components is found to depend on substitution and on solvent properties. A striking characteristic of the N-phenylnaphthalimides (in contrast to the N-alkyl derivatives) is the very efficient internal conversion which results in short fluorescence decay times and in low fluorescence and triplet yields. On the basis of the experimental results, it is suggested that solvent and geometric...

Smiles rearrangements promoted by complexation to chromium tricarbonyl

The chromium tricarbonyl promoted ipso-Smiles rearrangements of the O-phenyl to the N-phenyl derivatives of ephedrine and pseudoephedrine are reported.

A theoretical study of protonation and tautomerization of N-substituted aminoazobenzenes

Semiempirical AM1 and ab initio SCF STO-3G calculations with full geometry optimization were performed on aminoazobenzene (AAB) and its N-methyl (MAAB), N,N-dimethyl (DMAAB), and N-phenyl (PhAAB) derivatives, as well as their azonium and ammonium conjugated acids. AM1 calculations were also performed on hydrated cationic acids, in order to estimate the effect of amphiprotic solvents on tautomerization. In all the cases studied but DMAAB the AM1 and STO-3G proton affinity of the azo nitrogen was definitely higher than that of the amino nitrogen. For the amino nitrogen the calculated proton affinity was found to increase in the series AAB < MAAB < PhAAB < DMAAB. The calculated proton affinity of the azo nitrogen increased in the same order with the exception of the STO-3G results of PhAAB. The tautomerization energy/enthalpy (i.e. difference of the gas-phase proton affinity of the azo and the amino nitrogen) was found to increase in the series DMAAB < MAAB < AAB, the position of PhAAB in the series depending on whether the AM1 or STO-3G method was used. These results contradict the experimental data regarding aminoazobenzene protonation and tautomerization constants determined in various solvents, which indicates a strong effect of solvation on the protonation and tautomerization equilibria of aminoazobenzenes. AM1 calculations on hydrated cationic acids showed that solvation effects can be satisfactorily accounted for by enthalpy contributions in the case of tautomerization, because the order of tautomerization constants determined in methanol and dioxane–water mixture generally conforms with the order of tautomerization enthalpies with hydration included. However, the estimated proton affinities in water are still ranked in the same order as in vacuo which may indicate that entropy contributions play a much greater role in the case of protonation than in the case of tautomerization phenomena.

Siliciumverbindungen mit starken intramolekularen sterischen wechselwirkungen: LI . Arylisocyanid-insertionen in SiSi-bindungen einiger vierringe

Heating a mixture of a disilacyclobutane derivative with several aryl isocyanides leads to insertion of the isocyanide into the silicon-silicon bond, giving C,C-disilacyclopentanimines ( 5). The structure of the N-phenyl derivative ( 5a) was confirmed by X-ray crystallography. In the presence of palladium(II) acetate as catalyst, octaphenylcyclotetrasilane reacts with phenyl isocyanide to provide the corresponding tetrasilacyclopentanimine.

Herbicidal Activity of 2-Naphthyl Carbamates.

Herbicidal and phytotoxic activities of fifty-three 2-naphthyl carbamates against barnyardgrass (Echinochloa oryzicola Vasing.) and rice (Oryza sativa L.) were evaluated under paddy field conditions to clarify the relationships between chemical structure and the activity.Points clarified for the most suitable structure on herbicidal activity against barnyardgrass were as follows:1) N-Alkyl-N-phenyl was preferable for amino moiety in carbamate skeleton of 2-naphthyl carbamates.2) Among four types of carbamates of 2-naphthyl N-methyl-N-phenyl derivatives, thionotype thiocarbamates (O-2-naphthyl derivatives) showed the highest activity, and the next active was carbamates. Thiol-type thiocarbamates (S-2-naphthyl derivatives) and dithiocarbamates exhibited no activity.3) Of the N-alkyl group in O-2-naphthyl N-alkyl-N-phenylthiocarbamates, only methyl group showed the activity.4) With regard to substituents on the N-phenyl ring in O-2-naphthyl N-methyl-N-phenylthiocarbamates, there was a tendency that the activities of N-(meta-substituted phenyl) derivatives were higher than those of ortho- or para-substituents. For substituents on N-phenyl ring, hydrogen atom (=unsubstituted), methoxy and fluorine atom showed high activity.5) When N-(2-pyridyl) group was introduced into O-2-naphthyl thiocarbamates, the activities of most compounds were weak and lower than those of corresponding N-phenyl derivatives. But O-2-naphthyl N-(6-methoxy-2-pyridyl)-N-methylthiocarbamate exhibited much higher activity than corresponding N-(3-methoxy-phenyl) thiocarbamate.6) The activities of four types of carbamates having N-(6-methoxy-2-pyridyl)-N-methyl group were also examined. Thiono-type thiocarbamate showed the highest activity in a similar manner as N-phenyl derivatives.Among the tested carbamates, O-2-naphthyl N-(6-methoxy-2-pyridyl)-N-methylthiocarbamate showed the highest activity.

Enantioselective synthesis of optically active secondary amines via asymmetric reduction

The enantioselective synthesis of optically active secondary amines via the asymmetric reduction of N-substituted ketimines with various chiral hydride reagents, such as Itsuno's reagent ( 1), Corey's reagent ( 2), K glucoride ( 3), Sharpless' reagent ( 4), and Mosher's reagent ( 5) has been investigated. Among the hydride reagents examined, 1 gave the best results in terms of asymmetric induction. Thus, the reduction of N-phenylimine derivatives of aromatic ketones with 1 provided the corresponding amines in 96–98% yields with high optical induction, such as 73 % ee for acetophenone N-phenylimine ( 6a), 87 % ee for propiophenone N-phenylimine ( 6b), 88 % ee for bulyrophenone N-phenylimine ( 6c), and 71 % ee for isobutyrophenone N-phenylimine ( 6d). In the case of N-alkyl ketimine derivatives, the reduction afforded somewhat lower optical inductions as compared to those of N-phenyl derivatives, giving 46 % ee for acetophenone N-benzylimine ( 6f), 52 % ee for acetophnone N- n-heptylimine ( 6g) and 43 % ee for acetophenone N-cyclohexylimine ( 6h). However, the substitution of a bulky alkyl group on nitrogen of the ketimines increases remarkably the optical induction of product amine, such as 80 % ee for acetophenone N- tert-butylimine (6e). The reduction of N-substituted aliphatic ketimines gave very low optical inductions (7.4 – 24 % ee). The catalytic effects of oxazaborolidines ( 1a and 2a) in the reduction of ketimines with 1 and 2 were also examined.

Zinc Selective Ionophores for Potentiometric and Optical Sensors

Abstract Iminodiacetamide derivatives were synthesized and studied as ionophores in plasticized poly(vinyl chloride) membranes with potentiometric and optical transduction. The N-benzyl and N-phenyl derivatives proved to have a distinct zinc selectivity preferring Zn2+ over Ca2+, Na+ by factors of 6×105 and 3×104. respectively. All ionophores exhibit a serious proton interference (log KPot Zn ++, H + - 6) which suggests that all application of this type of ionophores based sensors are limited to hydrogen ion buffer solution at pH ≥ 6.

Mechanism of thiazolidine hydrolysis. Ring opening and hydrolysis of 1,3-thiazolidine derivatives of p-(dimethylamino)cinnamaldehyde

The hydrolysis reactions of 2-(p-(dimethylamino) styryl)-1,3-thiazolidine and the corresponding N-butyl and N-phenyl derivatives in the pH range 1-12 proceed via the iminium ion intermediate formed in an equilibrium ring-opening reaction. Such an intermediate was detected spectrophotometrically (λ max =480-525 nm). The fast formation of the iminium ion in ring mopening of the N-phenyl-1,3-thiazolidine could be monitored at pH 3-10. Ring opening involves a pH-independent reaction at pH>4, which proceeds 2.25-fold slower in D 2 O than in H 2 O, and hydronium ion catalysis at low pH. General acid catalysis in ring opening was observed with acetic acid buffers. Ring opening of the N-butylthiazolidine occurs 250-fold more rapidly than with the N-phenyl derivative. The plot of log k 0 vs pH for aldehyde formation from the N-butyl-substituted thiazolidine has five unit changes in slope

Influence of inorganic anions on the tautomeric equilibria of N-substituted aminoazobenzenes ? The evidence for ionic association

The influence of inorganic anions: perchlorate, chloride, sulphate, and hydrogen sulphate on the acid-base and tautomeric equilibria of 4-aminoazobenzene (AAB) and its N-ethyl (EAAB), N,N-diethyl (DEAAB), and N-phenyl (PhAAB) derivatives was investigated by UV-spectrophotometry in 80%:20% vol. ethanol:water system. The possible equilibrium models were evaluated by means of the nonlinear confluence analysis program STOICHIO in order to explain the observed dependence of the electronic spectra on acid and salt concentration. It was found that all the anions considered form 1:1 associates with both ammonium and azonium tautomers of the protonated aminoazobenzenes. The corresponding association constants were generally about one order of magnitude greater for SO42− than for the univalent ions. The azonium species were found to form more stable associates in all the cases except SO42−, which explains the observed shift of the tautomeric equilibrium towards the azonium form on increasing the mineral acid or salt concentration. Based on the obtained values of the molar absorption coefficients all but the PhAAB associates were found to be of the ionic pair type, with proton transfer taking place only in the last case. This was due to the greater basicity SO42−, compared with PhAAB. The association constant values obtained are discussed in terms of the tendency of the anions studied to associate, as well as in terms of the effect of solvation on the stability of the ionic pairs formed.

HEXAALKOXY AND HEXAARYLOXY 1,3,2λ5,4λ5-DIAZADIPHOSPHETIDINES

Abstract The reaction of the hexachlorodiazadiphosphetidine (MeNPCl3)2 with NaOR (R [dbnd] CH2CF3 or C6H5) yields the hexaalkoxy/aryloxy derivatives [MeNP(OR)3]2. On the other hand, the reaction of the N-phenyl derivative with NaOCH2CF3 affords the monophosphazene PhN[dbnd]P(OCH2CF3)3. Spectroscopic data for the new compounds are presented. The structure of the trifluoroethoxy derivative [MeNP(OCH2CF3)3]2 has been confirmed by a single crystal X-ray diffraction study. It crystallizes in the triclinic space group P1 with a = 9.024(2) A, b = 9.255(2) A, c = 9.944(2) A, α = 69.68(2)°, β = 60.16(2)°. γ = 78.88(2)°, and Z = 1. The final conventional unweighted residual is 0.044. The transformation of [MeNP(OCH2CF3)3]2 into its monomer at 110°C and its redistribution reaction with [MeNPF3]2 have been investigated by NMR spectroscopy. The formation of dimeric species appears to be favored by electron withdrawing groups at phosphorus promoting delocalization in the P[sbnd]N[sbnd]P system.

Diels-Alder reactions of dieno-pyranosides. Anomeric versus allylic stereoselection

A series of carbohydrate-derived dienes with different patterns of substitution on the pyranose ring were synthesized and their Diels-Alder reactions investigated. The diene moiety was incorporated into the pyranose ring by oxidation of 4-O-methanesulfonate esters of sugar derivatives to enals, followed by Witting alkenation. This new class of dienes underwent cycloaddition with maleimide or its N-phenyl derivative to give annulated pyranosides. The Diels-Alder reactions were highly stereoselective, giving single products in some cases. Structural analysis of the reaction products was carried out by NMR spectroscopy and X-ray crystallography. The results indicated a strong preference for the formation of the products resulting from addition of the dienophile to the face of the diene opposite the anomeric center. In cases where the anomeric and allylic substituents on the diene occupied opposite faces, addition of the dienophile occurred predominantly from the face opposite the more remote anomeric center

Synthesis and reactions of novel 1,3-dipyridinyl-1,3-propanediones

Claisen condensation leading to new 1,3-dipyridinyl-1,3-propanediones Id-If is described. The series of 3,5-dipyridinylpyrazoles IIa-IIf was completed and N-phenyl derivatives IIg-IIi, as well as isoxazoles IIIa and IIIb, were prepared.

Intramolecular nucleophilic attack by urea nitrogen. Reactivity–selectivity relationships for the general acid–base catalysed cyclisations of ureido acids and esters

The cyclisation of N-substituted hydantoic acids involves general acid–base catalysed attack of urea nitrogen on the CO2H group. The variation of the Brønsted exponents for the reactions of the N-methyl and N-phenyl derivatives (2) and (3) allows a choice between kinetically equivalent mechanisms. Stereoelectronic effects on the nucleophilic reactions of urea NH are considered, and a mechanism involving an initial rotation about the terminal C–N bond of the ureido group is suggested.

ChemInform Abstract: Studies on Decarboxylation Reactions. Part 6. Kinetic Study of Decarboxylation of 5‐Amino‐1,3,4‐oxadiazole‐2‐carboxylic Acid and Its N‐Phenyl Derivatives at High Hydrochloric Acid Concentrations.

ChemInformVolume 19, Issue 15 Preparative Organic Chemistry ChemInform Abstract: Studies on Decarboxylation Reactions. Part 6. Kinetic Study of Decarboxylation of 5-Amino-1,3,4-oxadiazole-2-carboxylic Acid and Its N-Phenyl Derivatives at High Hydrochloric Acid Concentrations. R. NOTO, R. NOTO Ist. Chim. Org., 90123 Palermo, ItalySearch for more papers by this authorG. WERBER, G. WERBER Ist. Chim. Org., 90123 Palermo, ItalySearch for more papers by this authorF. BUCCHERI, F. BUCCHERI Ist. Chim. Org., 90123 Palermo, ItalySearch for more papers by this authorC. ARNONE, C. ARNONE Ist. Chim. Org., 90123 Palermo, ItalySearch for more papers by this author R. NOTO, R. NOTO Ist. Chim. Org., 90123 Palermo, ItalySearch for more papers by this authorG. WERBER, G. WERBER Ist. Chim. Org., 90123 Palermo, ItalySearch for more papers by this authorF. BUCCHERI, F. BUCCHERI Ist. Chim. Org., 90123 Palermo, ItalySearch for more papers by this authorC. ARNONE, C. ARNONE Ist. Chim. Org., 90123 Palermo, ItalySearch for more papers by this author First published: April 12, 1988 https://doi.org/10.1002/chin.198815130AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume19, Issue15April 12, 1988 RelatedInformation