- Copper-Catalyzed Radical Cross-Coupling of Redox-Active Oxime Esters, Styrenes, and Boronic Acids
-
A visible-light-driven, copper-catalyzed three-component radical cross-coupling of oxime esters, styrenes, and boronic acids has been developed. Key steps of this protocol involve catalytic generation of an iminyl radical from a redox-active oxime ester and subsequent C?C bond cleavage to generate a cyanoalkyl radical. Upon its addition to styrene, the newly formed benzylic radical undergoes coupling with a boronic-acid-derived ArCuII complex to achieve 1,1-diarylmethane-containing alkylnitriles.
- Yu, Xiao-Ye,Zhao, Quan-Qing,Chen, Jun,Chen, Jia-Rong,Xiao, Wen-Jing
-
-
Read Online
- Metal-Free Enantioselective Oxidative Arylation of Alkenes: Hypervalent-Iodine-Promoted Oxidative C?C Bond Formation
-
The enantioselective oxyarylation of (E)-6-aryl-1-silyloxylhex-3-ene was achieved using a lactate-based chiral hypervalent iodine(III) reagent in the presence of boron trifluoride diethyl etherate. The silyl ether promotes the oxidative cyclization, and enhances the enantioselectivity. In addition, the corresponding aminoarylation was achieved.
- Shimogaki, Mio,Fujita, Morifumi,Sugimura, Takashi
-
p. 15797 - 15801
(2016/12/16)
-
- Controlling the photochemical reactions of alkenes by light-path length effects of a microchannel reactor
-
Photoirradiation of Me2CO-H2O solution of pent-4-en-1-ol (1a) with a high-pressure mercury lamp in a test tube gave 8-hydroxyoctan-2-one (3a) in 66 % yield along with oxetane (4a) and the isomer (4a') in 10 % yield. Irradiation of the running Me2CO-H2O solution of 1a in the flow system of a microchannel reactor (MCR) gave mainly 4a. The photoreaction of 1,1-diphenylethene (2a) with triethylamine gave a Markovnikov-type adduct (5a) and an anti-Markovnikov-type adduct (6a). The use of the MCR enhanced the production of 5a. These phenomena were explained by the light-path length effects of the MCR.
- Yamashita, Toshiaki,Matsushita, Shuhei,Nagatomo, Takuya,Yamauchi, Ryosuke,Yasuda, Masahide
-
p. 111 - 126
(2013/02/25)
-
- AZACYCLIC COMPOUNDS AS INHIBITORS OF SENSORY NEURONE SPECIFIC CHANNELS
-
Compounds of the formula (I), and pharmaceutically acceptable salts thereof, are found to be antagonists of SNS sodium channels. They are therefore useful as analgesic and neuroprotective agents wherein: X is -N- or -CH-; n is from 0 to 3.
- -
-
-
- CYCLIC ETHER COMPOUNDS AS SODIUM CHANNEL MODULATORS
-
A compound of the formula: wherein R 1 and R 2 each represents hydrogen, lower alkyl which may be substituted or acyl; R 3, R 4 and R 5 each represents lower alkyl which may be substituted or lower alkoxy which may be substituted or R 4 and R 5 taken together represent a 5-or 6-membered carbocyclic group; R 6 represents lower alkyl; Ar represents an aromatic group which may be substituted; ring A represents a 5-to 8-membered nitrogen-containing heterocyclic ring which may be substituted; X represents lower alkylene which may be substituted; Y represents carbon or nitrogen; Za represents CH 2, COCH 2, OCH 2, SCH 2, NHCH 2, etc.; Zb represents a bond or a divalent aliphatic hydrocarbon group which may be substituted and may contain O, N or S; and m represents an integer of 1 to 3, or a salt thereof is useful for a pharmaceutical composition for modulating sodium channel.
- -
-
-
- Histaprodifens: Synthesis, pharmacological in vitro evaluation, and molecular modeling of a new class of highly active and selective histamine H1-receptor agonists
-
A new class of histamine analogues characterized by a 3,3-diphenylpropyl substituent at the 2-position of the imidazole nucleus has been prepared outgoing from 4,4-diphenylbutyronitrile (4b) via cyclization of the corresponding methyl imidate 5b with 2-oxo-4-phthalimido-1-butyl acetate or 2-oxo-1,4-butandiol in liquid ammonia, followed by standard reactions. The title compounds displayed partial agonism on contractile H1 receptors of the guinea-pig ileum and endothelium-denuded aorta, respectively, except 10 (histaprodifen; 2-[2-(3,3-diphenylpropyl)1H-imidazol-4-yl]ethanamine) which was a full agonist in the ileum assay. While 10 was equipotent with histamine (1), methylhistaprodifen (13) and dimethylhistaprodifen (14) exceeded the functional potency of 1 by a factor of 3-5 (13) and 2-3 (14). Compounds 10 and 13-17 relaxed precontracted rat aortic rings (intact endothelium) with relative potencies of 3.3- up to 28-fold (compared with 1), displaying partial agonism as well. Agonist effects were sensitive to blockade by the selective H1-receptor antagonist mepyramine (pA2 ? 9 (guinea-pig) and pA2 ? 8 (rat aorta)). The affinity of 10 and 13-17 for guinea-pig H1 receptors increased 20- to 100-fold compared with 1. Two lower homologues of 10 were weak partial H1-receptor agonists while two higher homologues of 10 were silent antagonists endowed with micromolar affinity for rat and guinea-pig H1 receptors. In functional selectivity experiments, 10, 13, and 14 did not stimulate H2, H3, and several other neurotransmitter receptors. They displayed only low to moderate affinity for these sites (pA2 1 receptor were studied using molecular dynamics simulations. Remarkable differences were found between the binding modes of 10, 13, and 14 and that of 1. The imidazole ring of 10, 13, and 14 was placed 'upside down' compared with 1, making the interaction of the N(π)-atom with Tyr431 possible. This new orientation was mainly caused by the space filling substitution at the 2-position of the imidazole ring and influenced the location of the protonated N(α)-atom which was positioned more between TM III and TM VI. This orientation can explain both the increased relative potency and the maximum effect of 10, 13, and 14 compared with 1. Compound 13 (methylhistaprodifen; N(α)-methyl-2-[2-(3,3-diphenylpropyl)-1H-imidazol-4- yl]ethanamine) is the most potent histamine H1-receptor agonist reported so far in the literature and may become a valuable tool for the study of physiological and pathophysiological H1-receptor-mediated effects.
- Elz, Sigurd,Kramer, Kai,Pertz, Heinz H.,Detert, Heiner,Ter Laak, Anton M.,Kühne, Ronald,Schunack, Walter
-
p. 1071 - 1084
(2007/10/03)
-
- Ring-substituted histaprodifen analogues as partial agonists for histamine H1 receptors: Synthesis and structure-activity relationships
-
Thirteen racemic benzene ring-substituted analogues of histaprodifen (8a; 2-[2-(3,3-diphenylpropyl)-1H-imidazol-4-yl]ethanamine), a novel lead for potent and selective histamine H1-receptor agonists, have been prepared from substituted 4,4-diphenylbutyronitriles 5 via cyclization of the corresponding methyl butyrimidates 6 with 2-oxo-4-phthalimido-1-butyl acetate in liquid ammonia, followed by deprotection. Nitriles 5 were accessible by alkylation of either substituted diphenylmethanes with 3-bromopropionitrile or diethyl malonate with substituted 1-chloro-diphenylmethanes and subsequent standard reactions. The title compounds 8 displayed partial agonism on conctractile H1 receptors of the guinea-pig ileum (E(max) = 2-98% relative to histamine) and, compared with the endogenous agonist, were endowed with agonist potencies of 4-92%. The meta fluorinated (8c) and meta chlorinated (8f) analogues showed the highest relative potency in this series (95% confidence limits 85-99% and 78-102%), but did not exceed the value of the lead 8a (99- 124%). Compound 8c (2-[2-[3-(3-fluorophenyl)-3-phenylpropyl]-1H-imidazol-4- yl]ethanamine) was a partial agonist at contractile H1 receptors of the guinea-pig aorta (relative potency 154% vs. 100% for histamine) and at relaxation-mediating endothelial H1 receptors of the rat aorta (relative potency 556% vs. 100% for histamine) and matched with the functional behaviour of 8a. Agonism observed for each compound was sensitive to blockade by the selective H1-receptor antagonist mepyramine (pA2 ? 9 (guinea-pig) and pA2 ? 8 (rat aorta)). All histaprodifen analogues 8 stimulated neither histaminergic H2/H3 nor cholinergic M3 receptors. They displayed only low to moderate affinity for these sites (H2: pD'2 3/M3: pA2 1-receptor agonist, viz. 2- phenylhistamine. (C) 2000 Editions scientifiques et medicales Elsevier SAS.
- Elz, Sigurd,Kramer, Kai,Leschke, Christian,Schunack, Walter
-
-
- Reduction of activated thiopyridyl compounds by zinc metal
-
Starting from thiopyridyl compounds bearing a radical stabilizing group in α-position to the thiopyridyl moiety, the thiopyridyl group can be easily removed upon reduction by zinc metal in acetic acid.
- Boivin, Jean,Lallemand, Jean-Yves,Schmitt, Andreas,Zard, Samir Z.
-
p. 7243 - 7246
(2007/10/02)
-
- New Prenylamine analogues: synthesis and Ca2+-entry blocking activity
-
The synthesis of a series of diphenylalkylamine derivatives related to prenylamine is reported.The amphetamine group in the prenylamine structure was replaced by other moieties.In addition to substitutions in the aromatic rings, heteroatoms such as sulphur and oxygen were introduced in the chain.The calcium-entry blocking activity was assayed in binding experiments on a guinea-pig brain membrane preparation by displacing -nitrendipine.
- Caldirola, PM,Goot, H van der,Timmerman, H
-
p. 571 - 579
(2007/10/02)
-
- Photoinduced Nucleophilic Addition of Ammonia and Alkylamines to Aryl-Substituted Alkenes in the Presence of p-Dicyanobenzene
-
The photoamination of 1,1-diphenylpropene (1a) with ammonia and some primary alkylamines in the presence of p-dicyanobenzene gave the corresponding N-substituted 2-amino-1,1-diphenylpropane (2a-e) along with the formation of 3-methyl-4,4-diphenylbutanenitrile (3a), 1,1-diphenylpropane (4a), 3,3-diphenylpropene (5), and diphenylmethane (6).In the case of 1,1-diphenylethene (1b), N-substituted 1-amino-2,2-diphenylethane (2f-h), 4,4-diphenylbutanenitrile (3b), and 1,1-diphenylethane (4b) were produced.In photoamination with t-butylamine in acetonitrile, 3a and 3b were mainly formed as a consequence of the incorporation of acetonitrile to 1a and 1b.The photoamination of 1-phenyl-3,4-dihydronaphthalene (1c) with isopropylamine or t-butylamine gave cis- and trans-N-substituted 1-phenyl-2-amino-1,2,3,4-tetrahydronaphthalenes (15 and 16) in a ratio of ca. 8:2.The mechanism of photoamination is discussed in terms of a photochemical electron transfer of 1 to p-dicyanobenzene followed by a nucleophilic addition of the amine to the cation radical of 1.
- Yamashita, Toshiaki,Shiomori, Koichiro,Yasuda, Masahide,Kensuke, Shima
-
p. 366 - 374
(2007/10/02)
-
- Photochemical Reactions of 1,1-Diphenylpolycyanocyclopropanes in the Presence of Amines. Formal Extrusion of Dicyanomethylene
-
Irradiation of 1,1,2,2-tetracyano-3,3-diphenylcyclopropane in the presence of triethylamine results in the formation of 1,1-dicyano-2,2-diphenylethylene, which is suggested to be formed as a result of spontaneous 1,2 elimination of stabilized ion pairs in the initially formed amine-cyclopropane adducts.
- Tomioka, Hideo,Kanda, Masahiko
-
p. 2223 - 2226
(2007/10/02)
-
- Photochemical Addition of Tertiary Amines to Electrophilic Cyclopropranes via Single Electron Transfer
-
Irradiation of arylcyclopropanes bearing at least one electron-withdrawing group with a tertiary amine in acetonitrile resulted in the formation of the regioselective addition product of the amine along with the reduction product.
- Tomioka, Hideo,Miyagawa, Hiroshi
-
p. 1183 - 1184
(2007/10/02)
-
- Substituted 1,2,3,4-Tetrahydroaminonaphthols: Antihypertensive Agents, Calcium Channel Blockers, and Adrenergic Receptor Blockers with Catecholamine-Depleting Effects
-
Substituted 1,2,3,4-tetrahydroaminonaphthols were found to be calcium channel blockers with antihypertensive properties.These compounds also possessed adrenergic β-receptor blocking activity.From the structure-activity studies, no clear correlation emerged between the in vitro calcium channel blocking activity and the acute antihypertensive activity in cannulated spontaneously hypertensive rats.Extensive pharmacological testing of selected compounds indicated that aminonaphthols are antihypertensive agents with many pharmacological properties.The relative contribution of various pharmacological actions toward the observed antihypertensive activity is unclear.Since the clinically useful calcium channel blocker verapamil is structurally related to these compounds, one of the aminonaphthols, trans-3--1,2,3,4-tetrahydro-6,7-dimethoxy-2-naphthalenol (12), was compared with verapamil for calcium channel blocking activity, adrenergic blocking activity, and catecholamine-depleting activity.Both compopunds were found to be equipotent in these test systems.
- Atwal, Karnail S.,O'Reilly, Brian C.,Ruby, Eric P.,Turk, Chester F.,Aberg, Gunnar,et al.
-
p. 627 - 635
(2007/10/02)
-