34680-84-7Relevant academic research and scientific papers
Oxidation of the cyclopentanone and cyclohexanone alkyl derivatives in a pseudohomogeneous system without a phase transfer agent
Alimardanov,Garibov,Abbasov,Sadygov,Abdullaeva,Dzhafarova
experimental part, p. 1664 - 1670 (2011/12/02)
The reaction of catalytic oxidation of C5-C12 alkyl- and cycloalkylcyclopentanones and -cyclohexanones to lactones in a pseudohomogeneous system without the participation of phase transfer agents was investigated. It was established that the catalytic systems prepared on the basis of molybdenum and tungsten blue (MeOnBrm, where Me = Mo, W, n = 1, 2, m = 2, 3) and H3PO4 deposited on powdered activated carbon AG-3 at 40-60°C, at 5-6 h duration exhibit a high selectivity in the reaction of nucleophilic addition of oxygen to the ketones with the formation of the valero- and caprolactones. Pleiades Publishing, Ltd., 2011.
Laboratory evolution of robust and enantioselective Baeyer-Villiger monooxygenases for asymmetric catalysis
Reetz, Manfred T.,Wu, Sheng
experimental part, p. 15424 - 15432 (2010/02/16)
The Baeyer-Villiger Monooxygenase, Phenylacetone Monooxygenase (PAMO), recently discovered by Fraaije, Janssen, and co-workers, is unusually thermostable, which makes it a promising candidate for catalyzing enantioselective Baeyer-Villiger reactions in organic chemistry. Unfortunately, however, its substrate scope is very limited, reasonable reaction rates being observed essentially only with phenylacetone and similar linear phenyl-substituted analogs. Previous protein engineering attempts to broaden the range of substrate acceptance and to control enantioselectivity have been met with limited success, including rational design and directed evolution based on saturation mutagenesis with formation of focused mutant libraries, which may have to do with complex domain movements. In the present study, a new approach to laboratory evolution is described which has led to mutants showing unusually high activity and enantioselectivity in the oxidative kinetic resolution of a variety of 2-aryl and 2-alkylcyclohexanones which are not accepted by the wild-type (WT) PAMO and of a structurally very different bicyclic ketone. The new strategy exploits bioinformatics data derived from sequence alignment of eight different Baeyer-Villiger Monooxygenases, which in conjunction with the known X-ray structure of PAMO and induced fit docking suggests potential randomization sites, different from all previous approaches to focused library generation. Sites harboring highly conserved proline in a loop of the WT are targeted. The most active and enantioselective mutants retain the high thermostability of the parent WT PAMO. The success of the "proline" hypothesis in the present system calls for further testing in future laboratory evolution studies.
MMPP (Magnesium Monoperoxyphthalate) in acetonitrile; a new approach to the synthesis of lactones via Baeyer-Villiger oxidation of cyclic ketones
Hirano, Masao,Yakabe, Shigetaka,Satoh, Akiko,Clark, James H.,Morimoto, Takashi
, p. 4591 - 4596 (2007/10/03)
A variety of unsubstituted and mono- or di-substituted cycloalkanones can be oxidised with modest excess of magnesium monoperoxyphthalate hexahydrate in acetonitrile to produce the corresponding lactones in facile, selective, and high yielding manner.
A Direct Synthesis of γ-, δ-, and ε-Lactones Utilizing SmI2-induced Barbier-type Reaction in the Presence of Hexamethylphosphoric Triamide (HMPA)
Otsubo, Kenji,Kawamura, Kisa,Inanaga, Junji,Yamaguchi, Masaru
, p. 1487 - 1490 (2007/10/02)
By using an efficient reduction system of SmI2-THF-HMPA, the coupling reaction of β-, γ-, or δ-bromoesters with carbonyl compounds was completed within a minute at room temperature affording γ-, δ-, or ε-lactones, respectively, in good yields.Cp2ZrCl2 was also found to be effective for the coupling with ketones.
