35 research outputs found
Synthesis, Vasodilating, Antithrombotic and Cardioprotective Activity of Pyridyl Substituted 5-Silyl(Germyl)Isoxazolines-2
The reactions of [2+3] cycloaddition of pyridylnitrile oxides to vinyl- and allylgermanes
proceed regioselectively and afford 5-Ge-substituted isoxazolines-2. We have synthesized 9 new
pyridyl substituted 5-Si(Ge)-isoxazolines-2 and investigated their biological activity. The
vasodilating, anticoagulant and cardioprotective activities of 5-Si(Ge) substituted isoxazolines-2
have been studied in vitro and in vivo. Substitution of the silicon atom for the germanium one
leads to the significant increase in vasodilating, antithrombotic and cardioprotective activity. The
insertion of the methylene group between Ge and the isoxazoline ring reduces the vasodilating
activity. The most active isoxazoline - 3-(5‵-triethylgermyl-3‵-isoxazolinyl)pyridine hydrochloride
protects the heart from rhythm disturbances and lethality during ischaemia-reperfusion
Enhancing supply chain innovation and operational agility through knowledge acquisition from the social media: A microfoundational approach
This paper presents an examination of the interlocks between knowledge acquisition from social media (KAfSM), organizational microfoundation structure and design (OMFSaD), supply chain innovation (SCI), and operational agility (OA). These interlocks were tested on data collected from 172 managers/directors/CEOs of 96 firms operating in nine manufacturing industry sectors in Malaysia. Our findings suggest that OMFSaD plays a key role when interlinked with KAfSM. Furthermore, OMFSaD is significantly associated with SCI and OA, and SCI significantly correlates with OA and partially mediates the relationship between OMFSaD and OA. Our study’s outcomes are consistent with our understanding of IT‐enabled organizational capabilities—thus contributing to dynamic capability theory—and suggest that KAfSM helps to revamp processes, routines, and business operations in frequently changing environments. In this paper, we draw implications for research and practice
Cytotoxic Activity of Silyl- and Germyl-Substituted 4,4-Dioxo-3a,6a-Dihydrothieno[2,3−d]isoxazolines-2
The [2+3] dipolar cycloaddition of nitrile oxides to the double C = C bonds of thiophene-1, 1-dioxides leads to formation of the fused isoxazolines-2 (1, 2). Tumor growth inhibition of these compounds strongly depends on the nature of group IV A element increasing from slightly active tert-butyl derivatives to silicon and germanium containing analogues. The products of benzonitrile oxide cycloaddition have greater cytotoxic effect than the compounds obtained from the cycloaddition reaction of 2, 5-disubstituted thiophene-1, 1-dioxides with acetonitrile oxide. Fused silyl substituted isoxazolines-2 are stronger NO-inducers than their germyl and tert-butyl analogues
3-(4-Methylphenyl)-1-phenyl-3-(4,5,6,7-tetrahydro-1,2,3-benzoselenadiazol-4-yl)propan-1-one
In the title compound, C22H22N2OSe, the fused six-membered ring of the 4,5,6,7-tetrahydrobenzo[d][1,2,3] selenadiazole group adopts a near to envelope (E form) conformation and the five-membered 1,2,3-selenadiazole ring is essentially planar (r.m.s. deviation = 0.0059 Å). In the crystal, adjacent molecules are interlinked through weak intermolecular C—H⋯π interactions
Improved Conditions for the Synthesis and Transformations of Aminomethyl Selenophenothiophenes
A simple strategy for preparing aminomethyl selenopheno[3,2-b]- and selenopheno[2,3-b]thiophenes via the treatment of ethynylthiophenes with SeBr4 prepared in situ has been developed. Conjugated systems containing a selenophenothiophene moiety were constructed. Molecular structure of representative derivatives has been confirmed by X-ray
A Novel Method for the Bromination of Thiophenes
A novel, fast and convenient method for the bromination of thiophenes and oligothiophenes with N-bromosuccinimide (NBS) using ultrasonic irradiation is elaborated. The yield of bromothiophenes strongly depends on the initial thiophene structure and nature of the solvent
Tuning the reactivity of O-tert-butyldimethylsilylimidazolyl aminals towards organolithium reagents
O-tert-Butyldimethylsilylimidazolyl aminals are N,O-acetals that form readily from aldehydes, and although they function as aldehyde stabilizing and protecting groups under various conditions, we report here that they react with organolithium reagents similarly to the parent aldehydes. The mechanism involves the intermediate formation of a 2-imidazolyl anion as is exemplified by the isolation of 2-TBDMS-imidazole. Substitution of the imidazolyl moiety at the 2-position renders these aldehyde derivatives stable to organolithium reagents, thus allowing for the tuning of their reactivity
Tuning the reactivity of O-tert-butyldimethylsilylimidazolyl aminals towards organolithium reagents
O-tert-Butyldimethylsilylimidazolyl aminals are N,O-acetals that form readily from aldehydes, and although they function as aldehyde stabilizing and protecting groups under various conditions, we report here that they react with organolithium reagents similarly to the parent aldehydes. The mechanism involves the intermediate formation of a 2-imidazolyl anion as is exemplified by the isolation of 2-TBDMS-imidazole. Substitution of the imidazolyl moiety at the 2-position renders these aldehyde derivatives stable to organolithium reagents, thus allowing for the tuning of their reactivity