Chang-Ming Hu

Synthesis of 3-perfluoroalkyl-, including 3-trifluoromethyl-, substituted pyrazoles from perfluoroalkylacetylenes

Abstract 3-Perfluoroalkylpyrazoles 2 have been prepared in excellent yield by the reactions of perfluoroalkylacetylenes 1 with hydrazine monohydrate under mild conditions.

A novel synthesis of 2-per(poly)fluoroalkyl-1H-benzimidazoles or 2-per(poly) fluoroalkyl benzothiazoles

Abstract A new method for the preparation of 2-per(poly)fluoroalkyl-1 H -benzimidazoles or 2-per(poly)fluoroalkyl benzothiazoles from reaction of readily available α-per(poly)fluoroalkyl aldehydes with o -phenylenediamine or 2-aminobenzenethiol is presented. A possible reaction pathway is suggested.

Reformatsky reactions of ethyl 4,4-difluoro-3-ethoxy-4-halocrotonates: synthesis of 4,4-difluorocarbonate derivatives and 2-lactenones

Abstract Ethyl 4,4-difluoro-3-ethoxy-4-halocrotonates react with carbonyl compounds in the presence of zinc, giving 4,4-difluorocrotonate derivatives in good yields. A prolonged reaction time results in the formation of 4,4-difluoro-2-lactenones.

A new and concise method for the synthesis of 5-trifluoromethylisoxazoles

Abstract A highly effective synthesis of a series of 5-trifluoromethylisoxazoles 4 from pentafluoroethyl iodide ( 1 ) and various alkynes 2 by a two-step sequence is described.

SYNTHESIS OF (2R)-N-BOC-2-AMINO-4,4,4-TRIFLUOROBUTANOIC ACID USING TRIFLUOROMETHYLATION OF GARNER'S ALDEHYDE

Abstract Synthesis of enantiomerically pure (2 R )- N -Boc-2-amino-4,4,4-trifluorobutanoic acid ) 1 ) is described. The key step is trifluoromethylation of Garners aldehyde.

Synthesis of per(poly)fluoroalkylisoxazoles

Abstract 4,5-(1′,4′-Butylene)-3-per(poly)fluoroalkylisoxazoles 2 are synthesized by the reaction of the α-per(poly)fiuoroalkyl cyclohexanones 1 with hydroxylamine hydrochloride in the presence of potassium carbonate under reflux in ethanol. The isomeric 3,4-(1′,4′-butylene)-5-per (poly)fluoroalkylisoxazoles 3 can be prepared by a reaction of 1 , first with hydroxylamine hydrochloride to give the corresponding oximes 4 , followed by the treatment of the resultant reaction mixture with potassium carbonate in a one-pot procedure.

Study of the nucleophilic reaction of 2-mercaptoethanol with 1-fluoroalkyl-2-iodo-alkenes

Abstract The stepwise nucleophilic addition of 2-mercaptoethanol ( 2 ) to 1-fluoroalkyl-2-iodo-alkenes ( 1 ) was studied. Fluorine-containing building blocks of a new type ( 4 ) containing a fluorine atom, a fluoroalkyl-substituted double bond and a latent carbonyl group were synthesized in good yield via the intermediate thioethers 3 . A reasonable pathway is suggested.

One pot synthesis of 5-per(poly)fluoroalkyl-2,3-dihydro-1,4-diazepines

Abstract A series of 5-per(poly)fluoroalkyl-2,3-dihydro-1,4-diazepines have been synthesized from reaction of R f CF 2 I with vinyl ethyl ether and ethylenediamine. A possible reaction pathway is suggested.

NiCl2/Al-promoted addition of per(poly)fluoroalkyl iodides to per(poly)fluoroalkyl-substituted ethenes

Abstract In the presence of NiCl 2 · 6H 2 O/Al the addition of per(poly)fluoroalkyl iodides to per(poly)fluoroalkyl-substituted ethenes proceeds smoothly, giving the corresponding addition-elimination products in moderate yield.

tert-Butyl (S)-2,2-dimethyl-4-(Z-2′, 3′, 3′, 3′-tetrafluoro-1′-propenyl) oxazolidine-3-carboxylate: preparation and its nucleophilic reactions with alcohols

Abstract Optically active fluorine-containing alkene 2 has been prepared and its nucleophilic reactions with various alcohols to afford chiral trifluoromethylated enol ethers are exploited.