Search results for "Cyana"
showing 10 items of 585 documents
CCDC 1042614: Experimental Crystal Structure Determination
2015
Related Article: Tania Romero-Morcillo, Noelia De la Pinta, Lorena M. Callejo, Lucía Piñeiro-López, M. Carmen Muñoz, Gotzon Madariaga, Sacramento Ferrer, Tomasz Breczewski, Roberto Cortés, José A. Real|2015|Chem.-Eur.J.|21|12112|doi:10.1002/chem.201500310
CCDC 1432273: Experimental Crystal Structure Determination
2016
Related Article: Anna Świtlicka-Olszewska, Joanna Palion-Gazda, Tomasz Klemens, Barbara Machura, Julia Vallejo, Joan Cano, Francesc Lloret, Miguel Julve|2016|Dalton Trans.|45|10181|doi:10.1039/C6DT01160H
CCDC 993408: Experimental Crystal Structure Determination
2015
Related Article: Anna Świtlicka-Olszewska, Joanna Palion-Gazda, Tomasz Klemens, Barbara Machura, Julia Vallejo, Joan Cano, Francesc Lloret, Miguel Julve|2016|Dalton Trans.|45|10181|doi:10.1039/C6DT01160H
CCDC 1867784: Experimental Crystal Structure Determination
2019
Related Article: Joanna Palion-Gazda, Katarzyna Choroba, Barbara Machura, Anna Świtlicka, Rafał Kruszynski, Joan Cano, Francesc Lloret, Miguel Julve|2019|Dalton Trans.|48|17266|doi:10.1039/C9DT02976A
Synthesis of α-aminonitriles using aliphatic nitriles, α-amino acids, and hexacyanoferrate as universally applicable non-toxic cyanide sources
2018
In cyanation reactions, the cyanide source is often directly added to the reaction mixture, which restricts the choice of conditions. The spatial separation of cyanide release and consumption offers higher flexibility instead. Such a setting was used for the cyanation of iminium ions with a variety of different easy-to-handle HCN sources such as hexacyanoferrate, acetonitrile or α-amino acids. The latter substrates were first converted to their corresponding nitriles through oxidative decarboxylation. While glycine directly furnishes HCN in the oxidation step, the aliphatic nitriles derived from α-substituted amino acids can be further converted into the corresponding cyanohydrins in an oxi…
Synthesis of l -[4-11 C]Asparagine by Ring-Opening Nucleophilic 11 C-Cyanation Reaction of a Chiral Cyclic Sulfamidate Precursor
2018
The development of a convenient and rapid method to synthesize radiolabeled, enantiomerically pure amino acids (AAs) as potential positron emission tomography (PET) imaging agents for mapping various biochemical transformations in living organisms remains a challenge. This is especially true for the synthesis of carbon-11-labeled AAs given the short half-life of carbon-11 (11 C, t1/2 =20.4 min). A facile synthetic pathway to prepare enantiomerically pure 11 C-labeled l-asparagine was developed using a partially protected serine as a starting material with a four-step transformation providing a chiral five-membered cyclic sulfamidate as the radiolabeling precursor. Its structure and absolute…
Cell adhesion on UV-crosslinked polyurethane gels with adjustable mechanical strength and thermoresponsiveness
2021
Temperature-responsive polyurethane (PU) hydrogels represent a versatile material platform for modern tissue engineering and biomedical applications. However, besides intrinsic advantages such as high mechanical strength and a hydrolysable backbone composition, plain PU materials are generally lacking bio-adhesive properties. To overcome this shortcoming, the authors focus on the synthesis of thermoresponsive PU hydrogels with variable mechanical and cell adhesive properties obtained from linear precursor PUs based on poly(ethylene glycol)s (pEG) with different molar masses, isophorone diisocyanate, and a dimerizable dimethylmaleimide (DMMI)-diol. The cloud point temperatures of the dilute,…
Enantioselective Organocatalysis of Strecker and Mannich Reactions Based on Carbohydrates.
2007
Efficient organocatalysts for enantioselective Strecker and Mannich reactions were constructed from glucosamine as a readily accessible chiral scaffold. A variety of aromatic aldimines were subjected to hydrocyanation with good to excellent yield (72–98 %) and, in part, high enantioselectivity (69–95 % ee). Influence of the catalyst architecture on the enantioselectivity obviously arises from restrictions imposed on the conformational flexibility of the monosaccharidic backbone. In the asymmetric Mannich reaction moderate yields (up to 76 %) and enantioselectivities (up to 58 % ee) have been achieved with the described catalyst.
4-(2-Adamantyl)thiosemicarbazone
1984
Aus der Umsetzung von 4-(2-Adamantyl)thiosemicarbazid (1) mit den Carbonylverbindungen 2a-d gehen die 4-(2-Adamantyl)thiosemicarbazone 3a-d hervor. Die Startkomponente 1 ist aus 2-Aminoadamantan (4) uber das (2-Adamantyl)-isothiocyanat (5) zuganglich. Verbindung 5 und Vertreter des Strukturtyps 3 vermogen antivirale, antimykotische und antipyretische Wirkung auszuuben. Antiviral Agents, XXIV: 4-(2-Adamantyl)thiosemicarbazones Reactions of 4-(2-adamantyl)thiosemicarbazide (1) with the carbonyl compounds 2a-d yield the 4-(2-adamantyl)thiosemicarbazones 3a-d. The starting material 1 is accessible from 2-aminoadamantane (4) via 2-adamantyl isothiocyanate (5). Compound 5 and representatives of t…
Regio- and stereoselective synthesis of constrained enantiomeric β-amino acid derivatives
2008
Abstract Chlorosulfonyl isocyanate addition to (−)- and (+)-apopinene furnished monoterpene-fused β-lactams in highly regio- and stereospecific reactions. β-Lactams 5 and 13 exhibited reactivities similar to those of the cycloalkane-fused analogs and were easily converted to the β-amino acid and its protected derivatives. The base-catalyzed isomerization of the cis -amino ester afforded the corresponding trans -amino acid enantiomers in excellent yields. The complete isomerization is explained by the stability difference, which was estimated by ab initio calculations between the cis- and trans -diastereomers.