No abstract

Small ring heterocycles, such as epoxides and aziridines, are present in several natural products and are also highly versatile building blocks, frequently involved in the synthesis of numerous bioactive products and pharmaceuticals. Because of the potential for increased efficiency and selectivity, along with the advantages of environmentally benign synthetic procedures, multicomponent reactions (MCRs) have been explored in the synthesis and ring opening of these heterocyclic units. In this review, the recent advances in MCRs involving the synthesis and applications of epoxides and aziridines to the preparation of other heterocycles are discussed emphasizing the stereoselectivity of the reactions.

No abstract

No abstract

No abstract

INTRODUCTIONTolpopramine is a antihistamine and antipruritic drug used for skin diseases treatment such as allergy and itch. Previous syntheses relied on the Witting reaction to obtain 1-phenyl-1-(p-tolyl)ethane followed by hydroaminomethylation reaction using rhodium catalysis. This methodology does not provide conditions for an enantiosselective reaction. 1The compound 1 could be easily obtained from two Heck-Matsuda reactions from the N-protected allylamine 3. RESULTS AND DISCUSSIONStudies regarding the bis arylation of Nphthalimide allylamine (8) with and tetrafluoroborate 4-methoxy-benzenediazonium salt (6) provided only moderate results. Scheme 2: Conditions of bisarylation of Heck-Matsuda reactionWe then decided to optimize conditions to obtain the diarylated compounds from methyl cinnamate, 4-tolyl-diazonium tetrafluoroborate, methanol and Pd(OAc) 2 at 60°C. ACKNOWLEDGEMENTS