Showing papers on "Substituent published in 1987"

Directed Homogeneous Hydrogenation [New Synthetic Methods (65)]

Abstract: Stereochemical control is a major concern in the application of homogeneous catalysis to organic chemistry. In this context, the directed hydrogenation of olefins employing cationic rhodium or iridium catalysts has considerable potential, for very high selectivity can be attained under mild reaction conditions. The only requirement is a polar functional group in proximity to the double-bond which remains bound to the metal during the catalytic cycle and thereby controls the Stereochemical course of hydrogen delivery through the constraints of chelation. The substituent is most frequently a hydroxy group OH but can also be an ester, amide or carbamate group; other groups remain to be scrutinized. In cyclic compounds, directed hydrogenation can lead to face-selectivity, and the polar substituent may be in the β-, γ-, or δ-position to the double-bond. Acyclic stereoselection ensues with β- or γ-substituents in appropriate compounds, and the configuration of reduced product is predictable on the basis of simple rules. The application of optically active rhodium complexes leads to useful kinetic resolution procedures.

Basicity and Acidity of Azoles

Abstract: Publisher Summary This chapter provides a large collection of solution data and a thoroughly updated discussion of thermodynamic, kinetic, and structural results. This chapter covers aromatic azoles exclusively—that is, aromatic five-membered rings containing only carbon and nitrogen atoms, and their benzo derivatives. This chapter also discusses parent structure on theoretical grounds. One of the oldest methods to get insight into molecular structure, the study of acid-base properties, is today in rapid development. This is particularly true for the azoles. Gas phase studies of the acidity and basicity of azoles provides information on lone pair interactions, transmission of substituent effects in five-membered rings, relationships between acidity and basicity, aromatic substituent effects of nitrogen-linked derivatives and thermodynamic and kinetic parameters for proton transfer between nitrogen atoms in polyazoles. Because of the biological significance of some azoles (pyrrole, indole, imidazole, benzimidazole) and the consequences of acid–base equilibria in their functions, a continuous interest in the behavior in water is to be expected. In the case of N-unsubstituted imidazoles and pyrazoles, complexation of the pyridine-like nitrogen causes a considerable increase in the acidity of the pyrrolelike nitrogen.

12(R)-hydroxyicosatetraenoic acid: a cytochrome-P450-dependent arachidonate metabolite that inhibits Na+,K+-ATPase in the cornea.

Abstract: When corneal microsomes were incubated with arachidonic acid in the presence of an NADPH-generating system, four polar metabolites (compounds A-D) were formed. Synthesis of these metabolites could be inhibited by carbon monoxide, SKF 525A, and anti-cytochrome c reductase antibodies. One of the metabolites, compound C, was found to inhibit partially purified Na+,K+-ATPase from the corneal epithelium in a dose-dependent manner with an ID50 of approximately 50 nM. After compound C was purified by TLC and HPLC, it was found to have a UV absorption spectrum with a maximum absorbance at 236 nm suggesting the presence of a conjugated diene. Mass spectrometric analysis using positive- and negative-ionization modes was carried out on derivatized compound C that had been synthesized from a mixture of specifically labeled ([5,6,8,9,11,12,14,15-2H8]arachidonic acid) and unlabeled arachidonic acid. Abundant fragment ions were consistent with compound C being a monooxygenated derivative of arachidonic acid with a hydroxyl substituent at carbon-12 of the icosanoid backbone; all deuterium atoms from [2H8]arachidonate were retained in the structure. Oxidative ozonolysis yielded products indicating double bonds between carbons at positions 10 and 11 and positions 14 and 15 of the 20-carbon chain. Compound C was, therefore, characterized as a 12-hydroxyicosatetraenoic acid. However, only 12(R) isomer was found to be an inhibitor of the Na+,K+-ATPase from the corneal epithelium, suggesting that the biologically active compound C was 12(R)-hydroxy-5,8,10,14-icosatetraenoic acid. Such an inhibitor of Na+,K+-ATPase synthesized in the cornea may have an important role in regulating ocular transparency and aqueous human secretion.

Methylenecyclopropane rearrangement as a probe for free radical substituent effects. .sigma..bul. Values for commonly encountered conjugating and organometallic groups

Abstract: Une serie d'aryl-3 dimethyl-2,2 methylene-1 cyclopropanes, avec en position para du cycle benzenique les groupes suivants: NO 2 , NMe 2 , vinyl, isopropenyl, phenyl, cyclopropyl, CH 2 SiMe 3 , SiMe 3 , SnMe 3 -BOCH 2 CH 2 O et HgCl, est preparee. Ces composes se transposent thermiquement en les isopropylidenecyclopropanes correspondants

Photoreactive lenses with adamantane spiro compounds

Abstract: Photoreactive plastics lenses are disclosed which are coated or impregnated with an adamantane 2-spiro-benzo or naphthopyran and with a blue coloring photochromic benzo- or naphthopyran having a nitrogen containing substituent in the 2-position in the pyran ring. The lenses darken in sunlight and fade rapidly at ambient temperatures in the dark or in white light which does not contain a U.V. component. The combination of the yellow/orange coloring adamantane 2-spiro pyran compound with the purple/blue coloring pyran gives a desired brown/grey coloration in the sunlight-darkened lens. The invention includes novel blue-coloring pyran compounds in which the nitrogen-containing substituent in the 2-position is a phenyl group having an amino or substituted amino or nitrogen-containing heterocyclic substituent in the ortho- or para-position of the phenyl group. The basic chromene structure and the suffix N will be used to distinguish the blue-coloring pyran compounds having a nitrogen-containing substituent, namely: ##STR1##

Catalyst compositions, olefin/co copolymerization process and bisphosphine compounds

Abstract: Novel catalyst composition, characterized in that they are based upon a) a palladium compound, b) an anion of an acid with a pKa of less than 2, with the proviso that the acid is not a hydrohalogenic acid, c) a bisphosphine of the general formula R 1 R 2 P-R-PR 3 R 4 , wherein R 1 -R 4 are similar or dissimilar hydrocarbyl groups which may or may not be substituted with polar groups, with the proviso that at least one of the groups R 1 -R 4 represents a polarly substituted aryl group containing at least one polar substituent on a position ortho to phosphorus, and wherein R represents a bivalent organic bridging group containing at least two carbon atoms in the bridge, and d) optionally, a quinone.

Maltopentaose- and maltoheptaose-carrying styrene macromers and their homopolymers

Abstract: Le macromere N-(p-vinylbenzyl)-[O-α-D-glucopyrannosyl-(1→4)] n―1 -D-gluconamide (n=5 ou 7) est polymerise avec un amorceur radicalaire dans l'eau

Polymerization of carbon monoxide/olefin with P ligand having polar aryl group

Abstract: A polymerization process for the production of linear alternating polymers of carbon monoxide and at least one ethylenically unsaturated hydrocarbon employs a catalyst composition formed from a palladium compound, the anion of certain non-hydrohalogenic acids and certain bidentate ligands having ortho polar substitution within at least one monovalent phosphorus substituent and optionally a quinone. The polymer product is obtained in the form of globules.

Conformational analysis of synthetic heparin-like oligosaccharides containing α-L-idopyranosyluronic acid†

Abstract: High-field NMR spectroscopy of synthetic heparin-like di- and trisaccharides has afforded a complete set of inter-proton-coupling data on α-L-idopyranosyluronic acid, which have been used for conformational analysis. These data lead to the conclusion that α-L-iduronic acid may display considerable conformational freedom including 1C4, 4C1 and 2S0 (e.g. compound 1) conformers. The 2-O-sulphate substituent at iduronic acid tends to stabilize the 1C4 conformation (e.g. compounds 2 and 4). In addition carbohydrate substituents at position 4 hinder the 4C1 conformation (e.g. compound 3a,b versus 1). Furthermore, the conformation of α-L-idopyranosyluronic acid 2-sulphate is affected seriously by the substituent at position 2 of the non-reducing glucosamine residue. Thus the presence of an ammonium group (i.e. compound 7) leads to unexpected deformation of the 1C4 form of iduronic acid, whereas a sulphamino substituent at this position (e.g. compound 5a,b) brings about the 2S0 skew boat conformation. The iduronic acid moiety of a trisaccharide (compound 6), which represents a part of the anti-thrombin III-binding site of heparin, shows conformational preference for the 2S0 form in aqueous solution under low ionic conditions. However, increasing the ionic strength (e.g. 3 M NaCl) causes the conformational equilibrium to incline towards the 1C4 chair conformer. This feature may be indicative for the mechanism of conformational control as exerted by the AT-III protein upon heparin binding. Several molecular models of preferred conformers have been constructed; Nuclear Overhauser Enhancement data, exo-anomeric effect and Van der Waals interactions have been taken into account.

Spiro-oxazine compounds

Abstract: An azaindoline spiro-oxazine of the general formula (I): ##STR1## wherein R 1 represents an aliphatic or aromatic group; each of R 2 and R 3 independently represents a hydrogen atom, an aliphatic or aromatic group or an alkoxy group, or R 2 and R 3 together with the carbon atom to which they are attached represent an alicyclic group; R 4 represents a hydrogen atom or an aliphatic or aromatic group; ring A contains one or more nitrogen atoms in the ring and may be unsubstituted or substituted provided that there is no substituent on any nitrogen atom in the ring; and ring B may be unsubstituted or substituted by at least one substituent provided that the 6'-position in ring B is not substituted by an amine function or hydroxyl group. The spiro-oxazine compounds are useful for imparting photochromic properties to a plastics host material such as a plastics lens.

3-Aryluracils having an ether (thio) carbomyloxy or sulphomyloxy substituent on the aromatic moiety

Abstract: The invention is concerned with 3-aryluracils of the formula ##STR1## wherein R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are as described herein, as well as salts thereof and their manufacture, weed control compositions which contain such compounds as the active substance and the use of the active substances or compositions for weed control. The invention is also concerned with herbicidally-active starting materials and weed control compositions containing these.

Substituted anilides having antiandrogenic properties

Abstract: An acylanilide of the formula:- wherein R 1 or R 2 which may be the same or different, each is an electron-withdrawing substituent, alkylthio or phenylthio or R 1 is hydrogen, alkyl or alkoxy; wherein R 3 is hydrogen or halogen; wherein R 4 is hydrogen or alkyl, or is joined to R 5 as stated below: wherein R 5 is hydrogen, hydroxy, alkoxy or acyloxy, or is joined to R 4 to form an oxycarbonyl group; wherein R 6 is alkyl or halogenoalkyl, or has the formula -R 8 -or -A 2 -R 8 ; wherein A 1 is straight-chain alkylene, alkenylene or alkynylene; wherein A 2 is alkylene, alkenylene or alkynylene; and wherein R 7 and R 8 , which may be the same or different, each is selected from phenyl, substituted phenyl, naphthyl or 5-or 6-membered saturated or unsaturated heterocyclic. The compounds possess antiandrogenic properties and some of the compounds also possess progestational or antiprogestational activity.

Photosensitive member with enamine charge transport material

Abstract: The present invention provides a photosensitive member having a charge transporting layer containing a new enamine compound which has a specific substituent on the terminal carbon of the enamine bone, which give an excellent charge transportability.

2-Oxo-1-[[(substituted sulfonyl)amino]-carbonyl]azetidines

Abstract: Antibacterial activity is exhibited by 2-azetidinones having a 3-acylamino substituent and having an activating group in the 1-position of the formula ##STR1##

Synthesis and calcium channel antagonist activity of dialkyl 4-(dihydropyridinyl)-1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylates

Abstract: The sodium borohydride reduction of 3,5-disubstituted 1,4-dihydro-2,6-dimethyl-4-(pyridinyl)pyridines 2 and 5 in the presence of methyl, phenyl, or tert-butyl chloroformate afforded the respective 4-(dihydropyridinyl)-1,4-dihydropyridines 4 and 6 in good yield. Products 4 comprised a mixture of the 1,2- and 1,6-dihydropyridinyl regioisomers 4a and 4b where 4a was always the predominant regioisomer. Compounds possessing a 4-[dihydro-1-(phenoxycarbonyl)-3-pyridinyl] substituent, such as 26, were also a mixture of two regioisomers 26a and 26b, and each regioisomer existed as a mixture of two rotamers in Me2SO-d6 at 25 degrees C (26a', 26a'', and 26b', 26b'') due to restricted rotation about the nitrogen-to-carbonyl carbamate bond. The calcium antagonist activities for 4 and 6 were determined by using the muscarinic receptor-mediated Ca2+-dependent contraction of guinea pig ileal longitudinal smooth muscle. The relative order of activities for the 4-(dihydropyridinyl) analogues was 4-(dihydro-3-pyridinyl) greater than 4-(dihydro-4-pyridinyl). Increasing the size of the C-3(5) alkyl ester substituents increased activity. Compounds having nonidentical ester substituents were more active than those having identical ester substituents. Replacement of the C-3 and/or C-5 ester substituents by a cyano substituent(s) decreased activity significantly. An approximate 1:1 correlation between the IC50 value for inhibition of [3H]nitrendipine binding and inhibition of the tonic component of the muscarinic-induced contractile response was observed. The test results suggest that a 4-(dihydropyridinyl) substituent is bioisosteric with a 4-(nitrophenyl) substituent on a 1,4-dihydropyridine ring where m- and p-nitrophenyl are bioisosteric with the 4-[1,2(1,6)-dihydro-3-pyridinyl] 4 and 4-(1,2-dihydro-4-pyridinyl) 6 isomers, respectively.

Oligodeoxyribonucleoside methylphosphonates. NMR and UV spectroscopic studies of Rp-Rp and Sp-Sp methylphosphonate (Me) modified duplexes of (d[GGAATTCC])2.

Abstract: 1H NMR chemical shift assignments for the title compounds were made for most of the 1H signals using two-dimensional nuclear Overhauser effect (2D-NOE) data, which were also used to establish the absolute configuration at the modified phosphorus. The chemical shifts were similar to those reported [Broido, M.S., et al. (1985) Eur. J. Biochem. 150, 117-128] for the unmodified, parent, B-type duplex [d(GGAATTCC)]2. Differences in chemical shifts were mostly localized to the nucleotides on the 5'- and 3'-sides of the modified phosphorus. The Rp-Rp isomers exhibited UV-derived Tm values similar to that of the parent duplex. On the other hand, the Sp-Sp isomers generally exhibited lower Tm values which correlated with P-CH3--H3' (n-1 nucleotide) cross peak intensities and 31P spectral parameters. The combined data argue for increased steric interactions with the Sp-P-Me methyl group as the modification position is moved toward the center of the oligomer. All of the Tm results can be explained in terms of three factors which result from replacement of a phosphate by a methylphosphonate group: reduction of oligomer charge; electronic and other substituent effects; steric interactions.

Condensed Heteroaromatic Ring Systems. XII. Synthesis of Indole Derivatives from Ethyl 2-Bromocarbanilates

Abstract: The palladium-catalyzed reaction of ethyl 2-bromocarbanilate with trimethylsilylacetylene yielded ethyl 2- (trimethylsilylethynyl) carbanilate, which was treated with sodium ethoxide to give indole. The carbanilates having a methyl or a bromo substituent were similarly transformed to corresponding indole derivatives. Furthermore, pyrrolo [3, 2-b] -and pyrrolo [3, 2-c] pyridines were synthesized by this method.

17α-(substituted-methyl)-17β-hydroxy/esterified hydroxy steroids and pharmaceutical compositions containing them

Abstract: Steroids of the formula: ##STR1## which are characterized by a 17α-cyanomethyl, azidomethyl, methoxymethyl, phenylmethyl, or ethynylmethyl substituent and a 17β-hydroxy/esterified hydroxy substituent. The steroids of this invention have glucocorticoid, anti-glucocorticoid, progestational, or anti-progestational activity, depending on the particular structure.

1-Tert-alkyl-substituted naphthyridine and quinoline carboxylic acids as antibacterial agents

Abstract: There are disclosed new naphthyridine-and quinoline-carboxylic acids having a 1-tertiary-alkyl substituent, compositions containing them, and their use in treating bacterial infections in warm-blooded animals. Also disclosed are novel amines and intermediates used in the preparation of the naphthyridine-and quinoline-carboxylic acids.

Redox chemistry of the 9-anilinoacridine class of antitumor agents.

Abstract: 9-Anilinoacridines bearing a 1'-NHR substituent on the anilino ring undergo facile, chemically reversible, two-electron oxidation to quinone diimines. The chemical and electrochemical oxidation of three groups of 9-anilinoacridines (1'-substituted derivatives, together with 3'-substituted analogues and acridine-substituted analogues of the clinical antileukemic drug amsacrine) have been studied and their redox potentials determined. For aniline-substituted derivatives, redox potentials (E1/2) correlate well with substituent electronic properties, with electron-donating substituents facilitating oxidation. Substituents in the acridine ring have little effect on redox potentials, indicating minimal transmission of electronic effects from the acridine to the aniline rings. Although the broad class of 9-anilinoacridines show biological activity over a very wide range of structural variations, a 1'-NHR substituent is a common feature of the most active derivatives. Nevertheless, no clear quantitative relationships between redox potential and biological activity could be discerned, and the relevance of this redox chemistry to the mode of action of amsacrine and other 9-anilinoacridines remains unclear.

Condensation polymer containing the residue of a benzodioxylmethine compound and shaped articles produced therefrom

Abstract: Composition useful for molding into articles which as food containers, beverage bottles, cured structural plastics and the like comprising molding grade linear or unsaturated polyester or polycarbonate having reacted therewith or copolymerized therein the residue of one or more poly-methine compounds having the formula: ##STR1## wherein each R 1 is independently selected from cyano, carboxy, alkenyloxycarbonyl, or a substituted or unsubstituted alkoxycarbonyl, cycloalkoxoycarbonyl or aryloxycarbonyl radical; each R 2 is independently selected from one of the groups specified for R 1 or an unsubstituted or substituted aryl, carbamoyl, alkanoyl, cycloalkanoyl, aroyl, alkylsulfonyl, cycloalkylsulfonyl, arylsulfonyl or aromatic, heterocyclic radical; each R 3 is independently selected from hydrogen or an unsubstituted or substituted alkyl, cycloalkyl or aryl radical; A 1 and A 2 are independently selected from 1,4-phenylene radicals; and L is an organic linking group bonded by non-oxo carbon atoms to the oxygen atoms adjacent to L; provided the poly-methine compound bears at least one substituent that is reactive with one of the monomers from which the condensation polymer is derived. The polymethine residues are present in the polymer as an integral part of the polymer chain and absorb ultraviolet radiation in the range of about 250 to about 390 nm. The residues are non-extractable from the polymer and stable at the conditions at which the polymers are manufactured and processed.

Imidazopyridine compounds and processes for preparation thereof

Abstract: The invention relates to an imidazopyridine compound of the formula: ##STR1## wherein R1 is lower alkynyl, lower alkynyloxy(lower)alkyl or N,N-di(lower)alkylamino(lower)alkynyl, R2 is lower alkyl, R3 is mono (or di or tri)-phenyl(lower)alkyl substituted by one or more substituent(s) selected from cyano, carbamoyl, mono (or di or tri(phenyl(lower)alkylamino, acylamino, carboxy, esterified carboxy, hydroxy, hydroxy(lower)alkyl, acyloxy(lower)alkyl, acyloxy, mono (or di or tri)phenyl(lower)alkoxy, lower alkoxy(lower)alkoxy, tetrahydropyranyloxy, and acylamino(lower)alkyl or mono (or di or tri) phenyl(lower)alkyl substituted by lower alkyl and one additional substituent selected from hydroxy(lower)alkyl, amino, N-lower alkyl-N-acylamino, mono (or di or tri)phenyl(lower)alkylamino, acylamino and lower alkylamino, and R4 is hydrogen or lower alkyl, and a pharmaceutically acceptable salt thereof, useful in the treatment of ulcers.