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[摘要]：A study of the advantages of using manganese, an inexpensive and nontoxic metal, to perform stereoselective beta-elimination reactions and to promote sequential olefination reactions of aldehydes to obtain alpha,beta-unsaturated esters and amides is presented. Various elimination reactions, all of them characterized by Occurring with complete stereoselectivity and in high yields, were performed using active manganese (Mn*) as metalating agent. This ability of manganese has been applied to develop a novel and direct synthesis of (E)-alpha,beta-unsaturated esters or amides and (Z)-alpha,beta-unsaturated alpha-halo esters and alpha-choroamides through a Mn*-mediated sequential olefination protocol of aldehydes with dichloro esters or amides and trihalo esters or trichloroamides, respectively. |
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