Search results for "Moi"

Heterocycles from α-aminonitriles.

2014

Owing to their various modes of reactivity, α-aminonitriles represent versatile building blocks for the construction of a wide range of nitrogen heterocycles. The present Concept article focuses on synthetic methodologies using their bifunctional nature which is the basis of their reactivity as α-amino carbanions and as iminium ions. Reactions exclusively taking place on either the amine or on the nitrile moiety will not be considered.

Experimental and theoretical studies into the structural perturbations between neutral, oxidised and reduced forms of 1,4-dithiinoquinoxaline derivat…

2000

The syntheses and electrochemistry of thieno[3',4'r5,6][1,4]dithiino[2,3-b]quinoxaline (9), 2,3-bis(methylsulfanyl)[1,4]dithiino[2,3-b]quinoxaline (16) and 2,3-ethylenedisulfanyl[1,4]dithiino[2,3-b]quinoxaline (17) are reported, together with the X-ray crystal structures of 9, 16 and the charge-transfer complex 9.TCNQ. In the thieno derivative 9, the molecular structure undergoes a significant change from a boat conformer to a planar system, upon oxidation with TCNQ. Theoretical calculations show that oxidation leads to planarisation of the molecular structure due to the aromatisation of the dithiine moiety. The study of the oxidised/reduced species helps to rationalise the electrochemical …

Electroorganic synthesis of nitriles via a halogen-free domino oxidation–reduction sequence

2015

A direct electroorganic sequence yielding nitriles from oximes in undivided cells is reported. Despite the fact that intermediate nitrile oxides might be formed, the method is viable to prepare benzonitriles without substituents ortho to the aldoxime moiety. This constant current method is easy to perform for a broad scope of substrates and employs common electrodes, such as graphite and lead.

2019

Glycogen synthase kinase-3β (GSK-3β) represents a relevant drug target for the treatment of neurodegenerative pathologies including Alzheimer’s disease. We herein report on the optimization of a novel class of GSK-3β inhibitors based on the tofacitinib-derived screen hit 3-((3R,4R)-3-((7-chloro-9H-pyrimido[4,5-b]indol-4-yl)(methyl)amino)-4-methylpiperidin-1-yl)-3-oxopropanenitrile (1). We synthesized a series of 19 novel 7-chloro-9H-pyrimido[4,5-b]indole-based derivatives and studied their structure–activity relationships with focus on the cyanoacetyl piperidine moiety. We unveiled the crucial role of the nitrile group and its importance for the activity of this compound series. A successfu…

Moisture absorption, thermal conductivity and noise mitigation of clay based plasters: The influence of mineralogical and textural characteristics

2016

Abstract Three pre-mixed clay based plasters successfully employed in green building practices in several European countries (Spain, France, Germany, and United Kingdom), mainly used for interior wall coating and finishing, were tested in this paper. Their compositional and textural characteristics as well as plastic behaviour were investigated through a multi-analytical approach in a previous paper. A natural earth (Terra Rossa red soil sampled in north-western Sicily), theoretically appropriate for the production of earthen plaster, was also subjected to the same analytical routine and compared with the three commercially available products. Humidity control capacity by the determination …

1,4-Benzoquinones with Styryl Substituents

2002

2-Styryl-1,4-benzoquinone (1) and compounds 2 and 3 containing 1 as a substructure all proved to be highly reactive towards thermal or photochemical [4π + 2π] cyclodimerization reactions. Chemo-, regio- and stereoselective processes lead to dimers (compounds 1−10), which can undergo secondary reactions consisting of the addition of nucleophiles combined with a twofold keto-enol tautomerism (10 ⇄ 12). An alternative process is dehydrogenation/oxidation followed by an intramolecular [4π + 2π] cycloaddition (10 ⇄ 11). The same selective [4π + 2π] cyclodimerization can be observed in solution upon irradiation (e.g., 1a ⇄ 10a), in contrast to irradiation in the crystalline state which yields a […

Moisture dependence on mechanical properties of pine nuts from Pinus pinea L.

2012

Abstract Mechanical properties of pine nut shell are very important in the cracking process. Before industrial cracking shell moisture is adjusted by water soaking in order to avoid the breaking up of the nuts. In this work the moisture dependence of the mechanical properties of pine nut shells were studied in order to improve the industrial cracking process. Relationship between nut size and moisture content was studied and no significant differences were found for shell dimensions at four different moisture levels, 9.79%, 16.71%, 20.98% and 25.05% (dry basis). Compression tests were carried out on pine nuts at nine different moisture contents between 1.38% and 25.48% (db) and their main m…

The Afrotropical genus Rhinolaetia Schouteden, 1965 and its systematic position within Scutelleridae (Hemiptera: Heteroptera)

2016

The monotypic Afrotropical genus Rhinolaetia Schouteden, 1865 (Hemiptera: Heteroptera: Scutelleridae) is redescribed. The head, wings, female genitalia and habitus of Rhinolaetia overlaeti Schouteden, 1965 are illustrated. Morphological features of Rhinolaetia and selected representatives of six scutellerid subfamilies are listed and compared. The systematic position of this genus is briefly discussed. Close affinity of Rhinolaetia overlaeti with representatives of subfamilies Odontotarsinae and Odontoscelinae is observed.

Kognitiivinen kuorma ohjelmoinnin oppimisessa

2016

Ohjelmoinnin oppiminen on kognitiivisesti kuormittavaa. Kuorman hallintaan on löydetty mahdollisia hallintakeinoja, kuten tehtävätyyppien sovittaminen oppilaan taitotasolle, opetusmateriaalin esittäminen kuormaa vähentävästi ja tyypillisten vaikeuksien huomioiminen. Tässä kirjallisuuskatsauksessa eritellään näitä keinoja ja sovelletaan tietoa käytännön ohjelmointikursseihin. Learning programming happens to have high cognitive load on the learner. Studies have found multiple ways to manage this cognitive load. These ways are: providing right kind of task based on learners level, presenting study material in a load-reducing way and taking into consideration typical difficulties that students …

Synthesis of 1-Palmitoyl-2-((E)-9- and (E)-10-nitrooleoyl)-sn-glycero-3-phosphatidylcholines

2019

Extensive investigation of nitrated phospholipids in connection with various biologically important processes requires reliable access to suitable material. A selective chemical synthesis introducing a defined nitrofatty acid at the sn-2 position of a 2-lyso sn-glycero-3-phosphatidylcholine was developed. Given that the nitroalkene moiety of both reactant nitrofatty acid derivative and the product esters is characterised by particular sensitivity to nucleophile addition and, depending on the intermediate, subsequent olefin isomerisation and retro-Henry-type reaction, a reliable two-step ester formation was introduced. The activation of the nitrofatty acid succeeded after reaction with trich…