Search results for " molecule"

Photo-inhibition of Ab fibrillation mediated by a newly designed fluorinated oxadiazole

2015

Uncontrolled aggregation of amyloid beta peptide (A?) is the main cause of Alzheimer's Disease. Therapeutic approaches of intervention in amyloid diseases include the use of small molecules able to stabilize the soluble A? conformation, or to redirect the amyloidogenic pathway towards non-toxic and non-fibrillar states. Fluorometric measurements revealed that the 3-(4'-trifluoromethylphenyl)-5-(4'-methoxyphenyl)-1,2,4-oxadiazole, when irradiated, is able to interact with monomeric A? peptide readdressing the aggregation pathway toward the formation of amorphous aggregates as evidenced by means of CD, AFM, and SAXS measurements. We hypothesize that this compound, under radiation, forms a rea…

Synthesis of bi- and tricyclic β-lactam libraries in aqueous medium

2007

Water as a solvent is not only inexpensive and environmentally benign, but may allow good reactivity. The present work focuses on the application of a modified Ugi reaction, i.e. the Ugi four-centre three-component reaction (U-4C-3CR), in aqueous medium to construct β-lactam libraries. All the attempted reactions could be successfully performed in water. The reaction conditions under which the precipitation process was effective were investigated; no further work-up or purification was necessary. In several cases when less water-soluble β-amino acids were used, the precipitated products were isolated easily by simple filtration. In other cases, evaporation of the solvent was appropriate for…

Synthesis of various natural 8,12-elemanolides from artemisin

1989

Abstract This paper describes the chemical transformations of artemisin into various natural 8,12-elemanolides.

Struktur-Wirkungsbeziehungen bei Histaminanaloga, 14. Mitt. 4-Aminomethyl-benzimidazole und 9-Amino-naphth[1,2-d]imidazole

1977

Es wird die Darstellung der bicyclischen Histaminanaloga 4-Aminomethyl-benzimidazol (3a) und 4-Aminomethyl-4,5,6,7-tetrahydro-benzimidazol (3b) sowie der tricyclischen Analoga 9-Amino-6,7,8,9-tetrahydro-naphth[1,2-d]imidazol (6b) und 9-Amino-4,5,5a,6,7,8,9,9a-octahydro-naphth[1,2-d]imidazol (6c) beschrieben. 4-(Aminomethyl)benzimidazoles and 9-Aminonaphth[1,2-d]imidazoles Syntheses of the bicyclic histamine analogues 4-(aminomethyl)benzimidazole (3a) and 4-aminomethyl-4,5,6,7-tetrahydrobenzimidazole (3b) and of the tricyclic analogues 9-amino-6,7,8,9-tetrahydronaphth[1,2-d]imidazole (6b) and 9-amino-4,5,5a,6,7,8,9,9a-octahydronaphth[1,2-d]-imidazole (6c) are described.

Synthesis and Unusual NMR-Spectroscopic Behavior of a Strained Bicyclic Ammonium Salt

2018

Elektrocarboxylierung organischer Chloride mit Zehrandon

1984

Carboxylation par CO 2 de chloro-1 propane, -butane, α-chlorotoluene, dichlorobenzene, chloro-1 naphtalene et chloro-1p ethylbenzene en presence d'une anode de Al dans DMF-bromure de tetrabutylammonium

ChemInform Abstract: Cryptand-Like Anion Receptors

2010

The design of supramolecular hosts for anions began with simple diaza bicycles, named katapinands, and has evolved over the last 40 years to a number of elegantly designed receptors capable of binding many different anions. About the same time the term cryptand appeared in reference to another bicyclic compound that was selective for alkaline-earth ions. Since the first report these simple bicycles, a vast arena of hosts has appeared, including acyclic, monocyclic, and other multicyclic supramolecular receptors. Studies of these systems have revealed considerable information about anion coordination chemistry, including the fact that many of these complexes mimic their transition-metal coro…

Total synthesis of the monoterpenes (−)-mintlactone and (+)-isomintlactone

1992

Abstract The first total stereodirected synthesis of the monoterpenes (−)-mintlactone and (+)-isomintlactone from the same chiral starting product is described. A stereoselective, radical-mediated ring closure was the key step in both syntheses.

Cryptand-like anion receptors

2010

The design of supramolecular hosts for anions began with simple diaza bicycles, named katapinands, and has evolved over the last 40 years to a number of elegantly designed receptors capable of binding many different anions. About the same time the term cryptand appeared in reference to another bicyclic compound that was selective for alkaline-earth ions. Since the first report these simple bicycles, a vast arena of hosts has appeared, including acyclic, monocyclic, and other multicyclic supramolecular receptors. Studies of these systems have revealed considerable information about anion coordination chemistry, including the fact that many of these complexes mimic their transition-metal coro…

Cycloaddition reactions of benzothiete and hetero dienophiles for the synthesis of heterocyclic systems

1986

Abstract Benzothiete ( 1 ) undergoes cycloaddition reactions with hetero dienophiles with NN-, NO- or CO- double bonds, leading to six-membered heterocyclic ring systems of 2H-3,4-dihydro-1,2,3-benzothiadiazine ( 3 ), 4H-3,1,2-benzoxathiazine ( 4 ) and 4H-3,1-benzoxathiin.