Novel synthesis of dihydropyrans and 2,8-dioxabicylo[3.3.0]oct-3-enes using Mn(III)-based oxidative cyclization
作者:Van-Ha Nguyen、Hiroshi Nishino
DOI:10.1016/j.tetlet.2004.03.019
日期:2004.4
The Mn(III)-based reaction of 1,1-disubstituted alkenes with 2-(2-oxoethyl)malonates and 3-acetylpentane-1,4-diones gave novel substituted dihydropyrans and 2,8-dioxabicyclo[3.3.0]oct-3-enes in good yields, respectively. These routes rely on the nucleophilic character of the carbonyl-oxygen atoms of the malonates and pentanediones used to obtain the products by a cycloaddition reaction or cycloaddition–tandem
1,1-二取代的烯烃与2-(2-氧乙基)丙二酸酯和3-乙酰基戊烷-1,4-二酮的Mn(III)基反应产生了新的取代的二氢吡喃和2,8-二氧杂双环[3.3.0] oct -3-烯分别具有良好的收率。这些路线取决于丙二酸和戊二酮的羰基-氧原子的亲核特性,这些丙二酸和戊二酮用于通过环加成反应或环加成-串联环化反应获得产物。
Heterogeneous synthesis of 1,4-enediones and 1,4-diketones with manganese oxide molecular sieves OMS-2 as a recyclable catalyst
An efficient manganese oxide octahedral molecular sieves OMS-2-catalyzed chemoselective synthesis of 1,4-enediones and 1,4-diketones from 1,3-dicarbonyls and alpha-iodoacetophenones is described. The present catalytic system can be applied in one-pot, three-component reactions of methyl ketones, 1,3-dicarbonyls and iodine. Moreover, OMS-2 can be reused at least 5 times without loss of activity. (C) 2015 Elsevier B.V. All rights reserved.