128946-78-1Relevant articles and documents
The first 200-L scale asymmetric Baeyer-Villiger oxidation using a whole-cell biocatalyst
Baldwin, Christopher V.F.,Wohlgemuth, Roland,Woodley, John M.
, p. 660 - 665 (2008)
Biocatalytic Baeyer-Villiger oxidations using oxygen as an environmentally friendly oxidant in aqueous media have been shown to proceed with excellent stereo- and enantioselectivity for a large number of substrates at laboratory scale. These are good starting boundary conditions for process research and development compared to systems with reactive oxidants and flammable organic solvents. In this paper we discuss some of the considerations required to scale up a whole-cell biocatalytic oxidation from the laboratory to pilot-plant (200 L) scale. Issues for fermentation, bioconversion, and product recovery are discussed, supported by data from pilot-plant and scale-down experimentation. A simple fed-batch approach has been used.
Microbiological transformations 57. Facile and efficient resin-based in situ SFPR preparative-scale synthesis of an enantiopure unexpected lactone regioisomer via a baeyer-villiger oxidation process
Hilker, Iris,Gutierrez, Maria C.,Alphand, Veronique,Wohlgemuth, Roland,Furstoss, Roland
, p. 1955 - 1958 (2004)
Equation presented. The microbiological Baeyer-Villiger oxidation of (-)-bicyclo[3.2.0]hept-2-en-6-one allowed exclusive formation of the unexpected lactone regioisomer in 84% yield, high chemical purity, and enantiopure form. Substrate (25 g) was transformed in a 1 L bubble column reactor, following a in situ substrate feeding/product removal methodology, which afforded high volumetric productivity (1.2 g L-1 h -1). This illustrates the high sustainable chemistry advantages of such a process, simply conducted in aqueous medium, at room temperature and using atmospheric oxygen.
Microbial transformations, 56. Preparative scale asymmetric baeyer-villiger oxidation using a highly productive two-in-one resin-based in situ SFPR concept
Hilker, Iris,Alphand, Véronique,Wohlgemuth, Roland,Furstoss, Roland
, p. 203 - 214 (2004)
An efficient preparative scale process for achieving asymmetric Baeyer-Villiger oxidation - a reaction still very difficult to perform using conventional chemistry - is described. This process is based on a biocatalytic whole cells strategy - using a recombinant E. coli strain overexpressing cyclohexanone monooxygenase (CHMO) - combined with a two-in-one in situ substrate feeding and product removal concept (SFPR) using an adsorbent resin. The most efficient resin out of fourteen tested was used in three types of bioreactors (conventional, recycle and bubble column) that were compared. The best one proved to be the bubble column reactor, where 25 g (0.23 M) of rac-bicyclo[3.2.0]hept-2-en-6-one could be totally transformed using a one-litre vessel with a volumetric productivity of about 1 g L-1 h-1 (i.e., 7.7 mmol L-1 h-1). This led to the production of the two corresponding regioisomeric lactones, which were both obtained in excellent enantiomeric purity (ee > 98%) and high preparative yield (84%). To our knowledge, these results represent the best example of a (highly productive) preparative scale asymmetric Baeyer-Villiger oxidation.
(+)-(3S,4S)-3-butyl-4-vinylcyclopentene in brown algae of the genus Dictyopteris
Kajiwara, Tadahiko,Akakabe, Yoshihiko,Matsui, Kenji,Kodama, Kazuya,Koga, Harunobu,Nagakura, Takamitsu
, p. 529 - 532 (1997)
(-)-(3R,4R)-3-Butyl-4-vinylcyclopentene [(-)-1] was synthesized via (+)- (1S,5R)-3-oxabicyclo [3,3,0] oct-6-en-2-one. Synthetic (-)-1 coincided with the peak with later retention time of racemic (+)-1 in a chiral GC (CP- Cyclodex 236M), while the natural 1 in essential oils from the marine brown algae, Dictyopteris prolifera and D. sp. was identical with the earlier retention time peak. Thus, the absolute configuration of the natural product in Dictyopteris oils was determined as (+)-(3S,4S) with ca 100% enantiomeric excess.
Alloxazinium-Resins as Readily Available and Reusable Oxidation Catalysts
Arakawa, Yukihiro,Imada, Yasushi,Kawahara, Takayuki,Minagawa, Keiji
supporting information, p. 1728 - 1730 (2021/07/19)
N5-Modified alloxazinium salts including 5-ethyl-1,3-dimethylalloxazinium and 5-ethyl-1,3-dimethyl-8-(trifluoromethyl)- A lloxazinium salts were readily prepared as alloxazinium-resins from the corresponding N5-unmodified ingredients via the aerobic oxidationion exchange protocol, previously introduced by us for the preparation of isoalloxazine analogues, and their catalysis and reusability in H2O2 oxidations were evaluated.
Greener Preparation of 5-Ethyl-4a-hydroxyisoalloxazine and Its Use for Catalytic Aerobic Oxygenations
Oonishi, Takahiro,Kawahara, Takayuki,Arakawa, Yukihiro,Minagawa, Keiji,Imada, Yasushi
supporting information, p. 1791 - 1795 (2019/02/07)
Isoalloxazine ring systems are found in flavin cofactors in nature, and the simulation of their redox catalyses is an important task for developing sustainable catalytic oxidation reactions. Although 5-ethyl-4a-hydroxyisoalloxazines are among the most promising candidates as catalyst for such purposes, the use of them for laboratorial as well as industrial synthetic chemistry has so far been quite limited presumably due to the lack of their preparation methods readily, safely, and inexpensively available. In this communication, we introduce an environmentally benign and practical preparation of 5-ethyl-4a-hydroxy-3,7,8,10-tetramethylisoalloxazine (1EtOH) from 3,7,8,10-tetramethylisoalloxazine (1), in which conventional synthetic requirements, including (i) operations under inert conditions, (ii) risky or expensive chemicals, and (iii) isolation of labile intermediates, have all been dissolved. In addition, we have presented that 1EtOH could be an effective catalyst for Baeyer–Villiger oxidation as well as sulfoxidation with molecular oxygen (O2) as a terminal oxidant under suitable conditions, which is the first report on aerobic oxygenations catalyzed by 5-alkyl-4a-hydroxyisoalloxazines.
Controlling the Regioselectivity of Baeyer–Villiger Monooxygenases by Mutation of Active-Site Residues
Balke, Kathleen,B?umgen, Marcus,Bornscheuer, Uwe T.
, p. 1627 - 1638 (2017/08/26)
Baeyer–Villiger monooxygenase (BVMO)-mediated regiodivergent conversions of asymmetric ketones can lead to the formation of “normal” or “abnormal” lactones. In a previous study, we were able to change the regioselectivity of a BVMO by mutation of the active-site residues to smaller amino acids, which thus created more space. In this study, we demonstrate that this method can also be used for other BVMO/substrate combinations. We investigated the regioselectivity of 2-oxo-Δ3-4,5,5-trimethylcyclopentenylacetyl-CoA monooxygenase from Pseudomonas putida (OTEMO) for cis-bicyclo[3.2.0]hept-2-en-6-one (1) and trans-dihydrocarvone (2), and we were able to switch the regioselectivity of this enzyme for one of the substrate enantiomers. The OTEMO wild-type enzyme converted (?)-1 into an equal (50:50) mixture of the normal and abnormal products. The F255A/F443V variant produced 90 % of the normal product, whereas the W501V variant formed up to 98 % of the abnormal product. OTEMO F255A exclusively produced the normal lactone from (+)-2, whereas the wild-type enzyme was selective for the production of the abnormal product. The positions of these amino acids were equivalent to those mutated in the cyclohexanone monooxygenases from Arthrobacter sp. and Acinetobacter sp. (CHMOArthro and CHMOAcineto) to switch their regioselectivity towards (+)-2, which suggests that there are hot spots in the active site of BVMOs that can be targeted with the aim to change the regioselectivity.
