Allylic chlorination of terpenic olefins using a combination of MoCl5 and NaOCl

Abstract

MoCl 5 é usado como eficiente agente na cloração alílica de olefinas terpênicas na presença de NaOCl como doador de cloro. Vários terpenóides são convertidos aos cloretos de alila correspondentes em moderados a bons rendimentos em condições reacionais brandas e otimizadas. Diferentes precursores de molibdênio são estudados. Dentre eles, MoO 3 fornece bom rendimento, mas depois de um tempo de reação maior.MoCl 5 is applied as efficient agent in allylic chlorination of terpenic olefins in the presence of NaOCl as chlorine donor. Various terpenes are converted to the corresponding allylic chlorides in moderate to good yield under mild and optimized reaction conditions. Different molybdenum precursors are also studied. Among them, MoO 3 gives good yield, but after a longer reaction time.

Catalytic Allylic Chlorination of Natural Terpenic Olefins Using Supported and Nonsupported Lewis Acid Catalysts

“…When the reaction was carried out with MoCl 5 , the corresponding monochloride (b) is formed as the major product (entry 8). It appeared that the molybdenum catalyst promotes the formation of allylic monochloride (b) with a moderate selectivity of dichloride (c) and vinyl allyl dichloride (e) contrarily to what was reported previously [44].…”

“…According to the literature [38,43,44], the modest selectivity of dichlorinated product proved its presence for the first time in Lewis acid catalytic system. In order to confirm the formation of dichloride compound, a chlorination reaction starting from monochloride (b) was carried out and no conversion was observed.…”

“…Despite no reaction took place in the absence of Lewis acid catalyst, it has been reported that chlorine is usually generated from NaOCl [38,43,44]. e allylic chlorination reaction is probably based on the mild generation of electrophilic chlorine from NaOCl to a chlorination of the corresponding alkene.…”

“…e method has the advantage of mild reaction conditions when the reaction occurs in a smoothly twophase system (CH 2 Cl 2 /H 2 O) [38]. Different metallic Lewis acids in combination with NaOCl were studied for the allylic chlorination of terpenic olefins such as CeCl 3 , InCl 3 , or MoCl 5 [38,43,44]. e optimum solvent was reported to be the biphasic system of dichloromethane and water with addition of sodium hypochlorite under vigorous stirring to ensure the homogeneous distribution of the in situ generated electrophilic chlorine [38].…”

Catalytic Synthesis and Antifungal Activity of New Polychlorinated Natural Terpenes

“…In the course of our studies on monoterpenes and their derivatives, we have recently reported an extremely efficient method for the preparation of various allylic terpenic chlorides [14,[20][21][22][23]. Following our catalysis objective, we became interested in the preparation of a new class of polychlorinated natural product using Kharasch addition of CCl 4 catalyzed by iron acetylacetonate and to evaluate their inhibition capacity of the growth of the three pathogenic microorganisms.…”