Publications by authors named "Bernard R. Langlois"

Fluorinated moieties constitute important substituents used in many applications to modify the properties of molecules. The action of DAST onto Ruppert's reagent yields to a not isolable intermediate that can then react with various primary amines to give trifluoromethanesulfinamidines and trifluoromethanesulfanylamides. Such compounds were unknown until now and constitute interesting new families of fluorinated molecules.

View Article and Find Full Text PDF

An efficient preparation of new fluorinated lithium and ammonium sulfonimides, from the corresponding sulfonyl fluorides, is reported. These sulfonyl fluorides are reacted with benzylamine, then triflated. Due to the high leaving ability of fluorinated sulfonimides, the formed N-benzylsulfonimides are simply debenzylated with an alcohol.

View Article and Find Full Text PDF

An efficient preparation of several polyfluoroalkanesulfonyl fluorides is reported. This method, based on the synthesis of polyfluoroalkyl trimethyl silanes (precursors of polyfluoroalkylsulfinates) as intermediates, allows the successive transformations to be carried out in one pot. Moreover, these sulfonyl fluorides can be obtained from the corresponding sulfinates by electrophilic fluorination.

View Article and Find Full Text PDF

Beta-fluoroalkylated enones are efficient dienophiles in Diels-Alder cycloadditions to prepare various fluorinated cylic compounds. However, the presence of the fluoroalkyl moiety modifies the reactivity and the selectivity of these cycloadditions.

View Article and Find Full Text PDF

Various trifluoroacetamides and trifluoromethanesulfinamides, derived from chiral silylated amino alcohols, have been synthesized with the goal of achieving enantioselective nucleophilic trifluoromethylation. The best results were obtained with (R)-phenylglycinol derivatives, but the ee values did not exceed 30 %.

View Article and Find Full Text PDF

The syntheses of various alpha-trifluoromethylated nitrogen heterocycles have been achieved from readily available alpha-(trifluoromethyl)homoallylamine through a ring-closing metathesis.

View Article and Find Full Text PDF

Ethers of trifluoroacetaldehyde hemiaminals can undergo dehydrofluorination under basic conditions to provide ethers of difluoroketene hemiaminals. The latter behave as equivalents of difluoroacetamide or difluoroacetate anions towards various electrophiles, yielding a range of difluoromethylcarbonyl products.

View Article and Find Full Text PDF

Under Lewis acid activation, hemiaminals of trifluoroacetaldehyde and related (fluoroalkyl)aldehydes generate iminium species that can react with various nucleophiles to provide fluorinated amines.

View Article and Find Full Text PDF

Alkyl and aryl trifluoromethanethiosulfonates(1) (or selenosulfonates) were prepared in one step either from alkyl and aryl sulfenyl (or selenenyl) chlorides and sodium trifluoromethanesulfinate (3) or, more generally, from disulfides (or diselenides), 3, and bromine. The second method involved trifluoromethanesulfonyl bromide as key intermediate. Benzenethiosulfonates were obtained in a similar way from disulfides, benzenesulfinate, and bromine but benzeneselenosulfonates could not be obtained by the same method from diselenides.

View Article and Find Full Text PDF