Stewart R. Korn

Ionic liquids as media for nucleophilic fluorination

The use of Room Temperature Ionic Liquids (RTILs) for a variety of halogen exchange (Halex) fluorination processes using alkali metal fluorides is assessed. Whilst fluorination of a range of halogenated substrates is possible in good yield, the utility of RTILs as reusable, inert media for such reactions is limited by the gradual decomposition of the RTIL in the presence of highly basic fluoride ion.

Reactions involving fluoride ion. Part 401. Amines as initiators of fluoride ion catalysed reactions

Abstract Tetrakis(dimethylamino)ethene (TDAE) and trimethylamine react with anhydrous unsaturated fluorocarbons to produce, ‘in situ’, powerful fluoride- ion sources. These are used to initiate carbon- carbon bond forming reactions eg. oligomerisation and polyfluoroalkylation, and many of these reactions occur efficiently in the absence of a solvent.

Routes to building blocks for heterocyclic synthesis by reduction of ketene dithioacetals

Abstract Two general methods have been developed permitting the effective reduction of ketene dithioacetals to give substituted dithianes. Reduction with magnesium in methanol is less reliable than reduction with zinc in acetic acid. The greater inconsistency of magnesium in methanol has been investigated by a cyclic voltammetric study of the substrates. The utility of the dithianes has been successfully illustrated by cyclisations to afford, after deprotection, a variety of heterocyclic aldehydes.

Reactions involving fluoride ion. Part 37. ‘Proton Sponge’ hydrofluoride as a fluoride ion donor

Abstract ‘Proton Sponge’ hydrofluoride has been prepared and is totally soluble in acetonitrile; this system has been used to generate carbanions from hexafluoropropene and to form carbon-fluorine bonds by reaction with both 2,4,6-trichloropyrimidine and benzoyl chloride.

Reactions of ketene dithioacetals with bis-nucleophiles: Synthesis of novel heterocyclic thiols

Abstract The reactions of hydroxylamine, hydrazines, thiourea and guanidines with ketene dithioacetals are reported. The chemo- and regioselective aspects of the synthesis of the heterocyclic thiol products are contrasted with recently described processes based on related alkene substrates.

Three-component Heck–Diels–Alder cascade processes involving alkylallenes, aryl iodides and dienophiles

Abstract A wide variety of aryl/heteroaryl iodides undergo an intermolecular Heck reaction with alkylallenes to furnish 1,3-dienes. These subsequently react in situ with various dienophiles to give Diels–Alder adducts. The chemistry has been extended to incorporate cyclisation-anion capture methodology and the stereochemistry of the products has been determined.

Polyhalogenoheterocyclic compounds. Part 40. Tertiary aromatic amines as carbon-nucleophiles with activated perfluorinated aromatic compounds

Abstract The first examples illustrating that aromatic amines may act as carbon nucleophiles, in reactions with fluorinated aromatic compounds, are described. Products with potential for considerable charge separation are described.

Esterase catalysed enantioselective ring closure

Porcine liver esterase catalyses the reaction of γ-amino esters in water to give a mixture of the corresponding γ-lactam and the hydrolysis product, deacylation of the acyl enzyme intermediate by ring closure occurs with a high enantioselectivity giving an ee of 90% for the formation of (S)-5-phenyl-2-pyrrolidone from racemic ethyl 4-phenyl-4-aminobutanoate.

Reactions of aromatic amines with fluorinated alkenes and arenes

Abstract We have discovered some novel reactions which occur between certain fluorinated alkenes or arenes and appropriate aromatic amines. The scope and mechanism of these processes will be discussed.