Observação De Homodímero Do Tipo Bis-1,3-Benzodioxona Sintetizado via Metátese De Olefinas Da Piperina Catalisada Por Pré-Catalisadores De Ru(ii) Não Comerciais

Abstract

OBSERVATION OF BIS-1,3-BENZODIOXONE TYPE HOMODIMER SYNTHESIZED VIA PIPERINE OLEFIN METATHESIS CATALYZED BY NON-COMMERCIAL Ru(II) PRE-CATALYSTS. LN-1 and LN-2 are two Ru(II) complexes coordinated to the phosphine and amines simultaneously, each with two chlorides. PPh3 is the phosphine and the amine is piperidine (LN-1) and perhydroazepine (LN-2). The two compounds are complexes five-coordinated square pyramidal geometry, with the amine in the axial plane. LN-1 and LN-2 were tested for the first time as initiator for piperine self-metathesis olefin. The system variables chosen to this study were the reactional time (24, 48 and 72 h), catalyst:substrate ratio (1:1 and 1:10 mol) and temperature (25 e 50 ºC). Results were analyzed by GC-ME. None olefin metathesis product was noted in the experiments to 25 ºC for until 72 h, in any catalyst:substrate ration. However, to 50 ºC for 72 h, olefin metathesis product from piperine was observed. LN-1 presented yield of c.a. 29% of product in the mixture and LN-2 were c.a. 39%. The product is interesting and unheard, it has two 1,3-benzildiaxine groups, interleaved for one unsaturated carbon chain. In the experiments with catalyst:substrate ratio of 1:10 mol there was no product formation. The results were discussed in function of the electronic and steric properties of the ancillary ligand of LN1 and LN-2.