Daniel Couturier

ON the silylation of diarylcarbinols

Abstract Because of their dismutation into benzophenones and diphenylmethanes, it is necessary to use chlorotrimethylsilane and not triflic acid as a catalyst for the silylation of diarylcarbinol with hexamethyl-disilazane.

Decarboxylation of pyroglutamic acids with P2O5/CH3SO3H: a general synthesis of 5-aryl-2-pyrrolidinones

Abstract Treatment of pyroglutamic acids with acyl-activating reagents (P 2 O 5 /CH 3 SO 3 H, PPE ...), possibly in the presence of triethylamine, yields acyl iminium salts, that can react in-situ with aromatic compounds to give the corresponding 5-aryl-2-pyrrolidinones with good yields.

Reaction of trimethylsilyl derivatives with Meldrum's acid : A new and easy monofunctionalization of malonic acid

Abstract Treatment of Meldrums acid with silylated derivatives (amines, lactams or alcohols) yields very easily monofunctionalized malonic silyl esters. Hydrolysis of these silyl esters leads to the corresponding monoacids with a very good yield.

On the cyclization of acyliminium salts derived from pyroglutamic acid

Abstract The Friedel Crafts reaction of pyroglutamic acid derivative 9 gives an acyliminium salt which cyclize to the condensed N-acylheterocycle 6 thus providing an easy access to the amine 1 .

Studies on Pyrrolidinones. An Improved One Pot Synthesis of 1,2,3,5,10,10a-Hexahydrobenz[f]indolizine-3,10-dione

Abstract Starting from the readily available N,O-bis trimethylsilyl pyroglutamate, an easy high yield one pot synthesis of ketone 1 was described.

Studies on pyrrolidinones. On the decarboxylation of pyroglutamic acids and N-acyl prolines in acidic media

Abstract During attempted Friedel–Crafts cyclization of some arylmethyl pyroglutamic acids or of N-phenacyl prolines, decomposition of the activated form of the acid have been observed, giving new heterocyclic systems. This general decarboxylation occurred when there are difficulties to realize a Friedel–Crafts cyclization and is explained by geometrical or electronic considerations.

Reaction of Hexamethyldisilazane with Diacylhydrazines : An Easy 1,3,4-Oxadiazole Synthesis

Abstract The reaction of diacylhydrazines with hexamethyldisilazane in the presence of tetrabutylammonium fluoride as catalyst results in cyclisation to give 1,3,4-oxadiazoles in good yield.

Disilylated Compounds as Precursors of Heterocycles : Synthesis of Benzimidazoles, Triazoles, Furan and Pyrrole

Abstract The cyclization of disilylated compounds catalyzed by trifluoromethanesulfonic acid is an easy way to obtain some heterocycles such as benzimidazole, triazole, furan and pyrrole.

On the synthesis of dimethoxybenzyl cinnamates, monomers for electron transfer polymers

Abstract An economical way to obtain new monomers, precursors of electron transfer polymers, is described. These monomers were obtained by a Heck reaction between amino or halogeno-2,5-dimethoxydiarylmethane and methylacrylate. Different routes for the ionic reduction of various acetophenones to the corresponding diarylmethanes were studied. The yields and the nature of the by-products was stongly dependent upon the reaction conditions.

Studies on Pyrrolidinones. A New Rearrangement of Pyrrolo[1,2-b]Isoquinolines Derivatives

Abstract New lactones are obtained as by-products during the Friedel-Crafts cyclization of N-arylmethyl pyroglutamoyl chlorides. A mechanism based on N-acyliminium salts is proposed to explain their formation.