EWG assisted nucleophilic fluorination using PPHF: a strategy for the synthesis of 1,2,2-triaryl-2-fluoroethanones
作者:Anil Kumar、Anil K. Pal、Rishi D. Anand、Tej V. Singh、Paloth Venugopalan
DOI:10.1016/j.tet.2011.08.083
日期:2011.10
The nucleophilic fluorination of 1,2,2-triaryl-2-hydroxyethanones by fluoride ion has been carried out usingpyridiniumpoly(hydrogenfluoride) (PPHF) to give 1,2,2-triaryl-2-fluoroethanones in fairly good yield. The presence of electron withdrawing group (EWG), such as –COAr at the carbon bearing hydroxyl group facilitates such nucleophilic fluorination. The intermediacy of bridged oxiranyl ion and
Direct halogenation of alcohols with halosilanes under catalyst- and organic solvent-free reaction conditions
作者:Njomza Ajvazi、Stojan Stavber
DOI:10.1016/j.tetlet.2016.04.083
日期:2016.6
A chemoselective method for the direct halogenation of different types of alcohols with halosilanes under catalyst- and solvent-freereactionconditions (SFRC) is reported. Various primary, secondary and tertiary benzyl alcohols and tertiary alkyl alcohols were directly transformed to the corresponding benzyl and alkyl halides, respectively, using chlorotrimethylsilane (TMSCl) and bromotrimethylsilane
Ionic Liquids with Multi‐Active Sites Synergistically Catalyzed Metal‐Free Transformation of Alcohols Using Dimethyl Carbonate as an Environmental Solvent
Pyridine-based ionicliquids with multiple activesitessynergisticallycatalyzed C3 substitution of 4-hydroxycoumarin with alcohols in dimethylcarbonate was demonstrated. The system was efficient, economic and environmental and successfully applied for the synthesis of coumatetralyl as commercial rodenticide. And a mechanism involving a SN1 pathway, synergistically promoted effect of hydrogen bonding
Nickel‐catalyzed carbonyl arylation reaction employing aldehydes with aryl and allyl halides was demonstrated. Various aryl, α,β‐unsaturated aldehyde and aliphatic aldehydes can be converted into their corresponding secondary alcohols in moderate‐to‐high yields under the reductive coupling condition.