Nos travaux de thèse portent sur la mise au point de nouvelles méthodes de synthèse permettant l’accès de façon rapide et efficace à différents dérivés pyrazolo[1,5-a]pyrimidiniques diversement fonctionnalisés.La première partie de ce travail concerne l’étude et l’application de la condensation de la pyran-2-one avec les 5(3)-amino-3(5)-arylpyrazoles que ce soit par chauffage classique ou sous irradiation micro-onde. Par la suite, un nouveau procédé d’(hétéro)arylation pallado-catalysé direct régiosélectif a été mis à profit pour élaborer des pyrazolo[1,5-a]pyrimidines fonctionnalisées tant en position 3 que sur le méthyle situé sur le sommet 7 de la 5,7-diméthylpyrazolo[1,5-a]pyrimidine.Le dernier volet de ce mémoire a été consacré à la préparation des entités pyrazolo[1,5-a]pyrimidiniques substituées en position 7 par des motifs benzyliques et ce, via une procédure « one-pot », sous irradiation micro-onde, constituée d’une réaction d’arylation directe pallado-catalysée suivie d’une saponification-décarboxylation. / Our thesis works concern the development of new methods of synthesis allowing a rapid and effective access to variously functionalized pyrazolo [1,5-a] pyrimidines derivatives.First, we were explored the study and the application of the condensation of the pyran-2 one with 5(3)-amino-3 (5)-arylpyrazoles whether it is by classic heating or under microwaves. Indeed, we have described the first example of the direct and regioselective palladium-catalyzed (hetero)arylation of 5,7-dimethylpyrazolo[1,5-a]pyrimidine, the reaction may be inducted to occur at either an sp2 or an sp3 carbon atom.The last part of this report was dedicated to the preparation of some 7-substituted pyrazolo[1,5-a]pyrimidines via a one-pot two steps palladium-catalyzed direct CH-arylation followed by a saponification-decarboxylation.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / This work presents the synthesis of three series of trifluoromethylated heterocycles by using ultrasound irradiation, nomely pyrazolo[1,5-a]pyrimidines, 2,4- difluorophenylpyrazoles and pentafluorophenylpyrazoles. The reactions were performed between trifluoromethylated enones ([CF3C(O)CH=C(R)(OMe], where R = Me, Bu, i-Bu, Ph, 4-MeC6H4, 4-FC6H4, 4-ClC6H4, 4-BrC6H4, 4-IC6H4, thien-2-yl, naphthyl and biphenyl) with three different nucleophiles, nomely (3)(5)-amine-(5)(3)- methylpyrazole, 2,4-difluorophenylhydrazine hydrochloride and pentafluorophenylhydrazine. The trifluoromethylated pyrazolo[1,5-a]pyrimidines were obtained within 5 minutes, giving yields of 61-98 %. The series of 2,4- difluorophenylpyrazoles was obtained in good yields (54-85 %) within 15 minutes by acidifying the reaction medium with PTSA. In the case of the pentafluorophenylpyrazoles, two steps were needed: Firtly the respective 4,5- dihydropentafluorophenylpyrazoles were synthesised and then subsequently submitted to dehydration reactions using PTSA for 15 minutes, giving yields of 54-81 %. The synthesized compounds were identified by 1H and 13C, and by 19F NMR spectroscopy in the some case, mass spectrometry and X-ray diffraction. In some cases homo/heteronuclear spatial interactions involving fluorine atoms have been useful for confirming the identity of the obtained isomer. Another part of this tesis was the synthesis of four mechanically interlocked molecules. Two [2]rotaxanes carrying an ester group in the macrocycle unity were synthesized by using two threads (fumaramide and succinamide derivatives). Once synthesized these [2]rotaxanes were submmited to hydrolysis reactions to give [2]rotaxanes with acid carboxilic group. These macromolecules were synthesized aiming at the formation of MOFs (metal organic frameworks). The synthesis of this compound was carried out by using copper (II) and [2]rotaxane derivative fumaramide. This product was identified by X-ray diffractometry. / Este trabalho apresenta a síntese de três séries de heterociclos trifluorometilados, utilizando irradiação de ultrassom (pirazolo[1,5-a]pirimidinas, 2,4-difluorofenilpirazóis e pentafluorofenilpirazóis). As reações foram realizadas entre enonas trifluorometiladas ([CF3C(O)CH=C(R)(OMe], onde R = Me, Bu, i-Bu, Ph, 4-Me-C6H4, 4-F-C6H4, 4-Cl-C6H4, 4-Br-C6H4, 4-I-C6H4, tien-2-il, bifen-2-il e naftil) e três dinucleófilos diferentes 3-amino-5-metilpirazol, cloridrato de 2,4-difluorofenilhidrazina e pentafluorofenilhidrazina. As pirazolo[1,5-a]pirimidinas trifluorometiladas foram obtidas em 5 minutos de reação com rendimentos de 61-98 %. A série de 2,4- difluorofenilpirazóis foi obtida, acidificando-se o meio de reação com APTS em 15 minutos de reação, e obtendo-se bons rendimentos (54-85 %) no processo. No caso dos pentafluorofenilpirazóis, foram necessárias duas etapas de reação: a primeira a síntese de 4,5-di-idropentafluorofenilpirazóis, e seguida de posterior reação de desidratação utilizando APTS em 15 minutos de reação, obtendo-se produtos com rendimentos de 54-81 %. Após a síntese desses compostos, os mesmos foram identificados por técnicas de RMN de 1H e 13C e de 19F, em alguns casos, espectrometria de massas e difratometria de raios-X. Em alguns casos, através de RMN, foi possível observar interações espaciais do tipo homo/heteronuclear envolvendo átomos de flúor, úteis na confirmação do isômero obtido. Em outra etapa deste trabalho foi desenvolvida a síntese de quatro moléculas mecanicamente entrelaçadas. Foram sintetizados dois [2]rotaxanos com grupamento éster no macrociclo, utilizando dois filamentos lineares (derivados da fumaramida de succinamida). Após a síntese desses [2]rotaxanos, foi realizada a reação de hidrólise dos grupamentos ésteres do macrociclo em grupamento ácidos. Essas macromoléculas foram sintetizadas visando à formação dos MOFs (Redes de metais orgânicas). A síntese desse composto foi realizada utilizando cobre (II) e o [2]rotaxano derivado da fumaramida. Esse produto foi identificado através de difratometria de Raios-X.