616-75-1Relevant articles and documents
Preparation of mono-substituted malonic acid half oxyesters (SMAHOs)
Condon, Sylvie,Le Gall, Erwan,Pichon, Christophe,Presset, Marc,Xavier, Tania
, p. 2085 - 2094 (2021/09/02)
The use of mono-substituted malonic acid half oxyesters (SMAHOs) has been hampered by the sporadic references describing their preparation. An evaluation of different approaches has been achieved, allowing to define the best strategies to introduce diversity on both the malonic position and the ester function. A classical alkylation step of a malonate by an alkyl halide followed by a monosaponification gave access to reagents bearing different substituents at the malonic position, including functionalized derivatives. On the other hand, the development of a monoesterification step of a substituted malonic acid derivative proved to be the best entry for diversity at the ester function, rather than the use of an intermediate Meldrum acid. Both these transformations are characterized by their simplicity and efficiency, allowing a straightforward access to SMAHOs from cheap starting materials.
Exploration of New Biomass-Derived Solvents: Application to Carboxylation Reactions
Gevorgyan, Ashot,Hopmann, Kathrin H.,Bayer, Annette
, p. 2080 - 2088 (2020/02/20)
A range of hitherto unexplored biomass-derived chemicals have been evaluated as new sustainable solvents for a large variety of CO2-based carboxylation reactions. Known biomass-derived solvents (biosolvents) are also included in the study and the results are compared with commonly used solvents for the reactions. Biosolvents can be efficiently applied in a variety of carboxylation reactions, such as Cu-catalyzed carboxylation of organoboranes and organoboronates, metal-catalyzed hydrocarboxylation, borocarboxylation, and other related reactions. For many of these reactions, the use of biosolvents provides comparable or better yields than the commonly used solvents. The best biosolvents identified are the so far unexplored candidates isosorbide dimethyl ether, acetaldehyde diethyl acetal, rose oxide, and eucalyptol, alongside the known biosolvent 2-methyltetrahydrofuran. This strategy was used for the synthesis of the commercial drugs Fenoprofen and Flurbiprofen.
Exploring the Promiscuous Enzymatic Activation of Unnatural Polyketide Extender Units in Vitro and in Vivo for Monensin Biosynthesis
Grote, Marius,Schulz, Frank
, p. 1183 - 1189 (2019/03/11)
The incorporation of new-to-nature extender units into polyketide synthesis is an important source for diversity yet is restricted by limited availability of suitably activated building blocks in vivo. We here describe a straightforward workflow for the biogenic activation of commercially available new-to-nature extender units. Firstly, the substrate scope of a highly flexible malonyl co-enzyme A synthetase from Streptomyces cinnamonensis was characterized. The results were matched by in vivo experiments in which the said extender units were accepted by both the polyketide synthase and the accessory enzymes of the monensin biosynthetic pathway. The experiments gave rise to a series of predictable monensin derivatives by the exploitation of the innate substrate promiscuity of an acyltransferase and downstream enzyme functions.