نتایج جستجو برای: electron rich aromatic compounds
تعداد نتایج: 700242 فیلتر نتایج به سال:
The aim of the present work is to study the chemical composition of Turkish propolis. Propolis samples were collected from different regions of Turkey (Bursa, Erzurum-Askale, Gumushane-Sogutagil and Trabzon-Caglayan) in 1999. Ethanol extracts of propolis (EEP) were prepared for chemical analysis, using gas chromatograph coupled with mass spectrometry (GC-MS). Our findings show that propolis sam...
The role of microorganisms in the cycling of sedimentary organic carbon is a crucial one. To better understand relationships between molecular composition of a potentially bioavailable fraction of organic matter and microbial populations, bacterial and archaeal communities were characterized using pyrosequencing-based 16S rRNA gene analysis in surface (top 30 cm) and subsurface/deeper sediments...
Various electron-rich aromatic and olefinic donors (D) are readily converted to their cation radicals (D!!) in the presence of strong protic acids, even in nonpolar solvents such as dichloromethane. By using the three prototypical organic donors octamethylbiphenylene (OMB), adamantylideneadamantane (AA) and the isomeric fused homoadamantene (FHA), we identify the protonated donor (D-H) as the e...
A highly enantioselective Friedel-Crafts alkylation of electron-rich aromatic nucleophiles catalyzed by scandium(III) triflate-pyridyl(bis)oxazoline complexes has been accomplished. The reaction involves alpha,beta-unsaturated acyl phosphonates as electrophiles and primarily substituted indoles as nucleophiles. The reactive acyl phosphonate product is converted to the corresponding ester or ami...
Benzoyl azides were used for the direct and atom economic C–H amidation of electron rich heteroarenes in the presence of phosphoric acid, a photocatalyst and visible light. Hetero-aromatic amides are obtained in good yields at very mild reaction conditions with dinitrogen as the only by-product. The reaction allows the use of aryl-, heteroarylor alkenyl acyl azides and has a wide scope for hete...
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