875901-64-7Relevant academic research and scientific papers
CO2-expanded liquids as solvents to enhance activity of Pseudozyma antarctica lipase B towards ortho-substituted 1-phenylethanols
Hoang, Hai Nam,Koesoema, Afifa Ayu,Matsuda, Tomoko,Otsu, Moeko,Suzuki, Yuichi,Tamura, Mayumi
supporting information, (2020/09/18)
Pseudozyma (Candida) antarctica lipase B (CAL-B, Novozym 435) is one of the most widely used and outstanding biocatalysts. However, CAL-B-catalyzed transesterification of ortho-substituted 1-phenylethanol analogs suffers low conversion. In this research, the reactions were accelerated by using CO2-expanded liquids, liquids expanded by dissolving pressurized CO2, such as CO2-expanded hexane or CO2-expanded MeTHF.
Asymmetric Chemoenzymatic Reductive Acylation of Ketones by a Combined Iron-Catalyzed Hydrogenation–Racemization and Enzymatic Resolution Cascade
El-Sepelgy, Osama,Brzozowska, Aleksandra,Rueping, Magnus
, p. 1664 - 1668 (2017/04/27)
A general and practical process for the conversion of prochiral ketones into the corresponding chiral acetates has been realized. An iron carbonyl complex is reported to catalyze the hydrogenation–dehydrogenation–hydrogenation of prochiral ketones. By merging the iron-catalyzed redox reactions with enantioselective enzymatic acylations a wide range of benzylic, aliphatic and (hetero)aromatic ketones, as well as diketones, were reductively acylated. The corresponding products were isolated with high yields and enantioselectivities. The use of an iron catalyst together with molecular hydrogen as the hydrogen donor and readily available ethyl acetate as acyl donor make this cascade process highly interesting in terms of both economic value and environmental credentials.
Dynamic kinetic resolution of a wide range of secondary alcohols: Cooperation of dicarbonylchlorido(pentabenzylcyclopentadienyl)ruthenium and CAL-B
Paeivioe, Mari,Mavrynsky, Denys,Leino, Reko,Kanerva, Liisa T.
supporting information; experimental part, p. 1452 - 1457 (2011/04/22)
The substrate scope in the dynamic kinetic resolution ofsecondary alcohols was studied by using 31 structurallydifferent alcohols and isopropenyl acetate in the presence ofdicarbonylchlorido(pentabenzylcyclopentadienyl)rutheniumand Candida antarctica lipase B (Novozym 435, CAL-B) in toluene. The enzyme and the ruthenium complex were shown to function in a highly compatible manner allowing the conversion of the racemic alcohols into the (R)-acetates in practically theoretical yields and, in most cases, ee values exceeding 99%. The results are fully comparable to those published previously by using earlier reported, state-of-the-art ruthenium-based catalysts for the alcohol racemization. A clear benefit of the dicarbonylchlorido(pentabenzylcyclopentadienyl)ruthenium system, when compared to other (cyclopentadienyl)ruthenium racemization catalysts, is its simple and cost-efficient preparation. The substrate scope of 31 secondary alcohols was studied in the dynamic kinetic resolution by utilizing dicarbonylchlorido(pentabenzylcyclopentadienyl)rutheniumand Candida antarctica lipase B (CAL-B) in the acylation with isopropenyl acetate in toluene at room temperature. The secondary alcohols were transformed into highly enantiopure (R)-acetates (in most cases ee > 99%) in close to quantitative isolatedyields. Copyright
Rapid, room-temperature acylative kinetic resolution of sec-alcohols using atropisomeric 4-aminopyridine/triphenylphosphine catalysis
Spivey, Alan C.,Arseniyadis, Stellios,Fekner, Tomasz,Maddaford, Adrian,Leese, David P.
, p. 295 - 301 (2007/10/03)
Two new atropisomeric 4-aminopyridine-based nucleophilic catalysts containing terphenyl 'blocking groups' have been prepared and evaluated for kinetic resolution (KR) of aryl alkyl sec-alcohols. One of these biaryls is shown to be the most selective atropisomeric catalyst yet prepared for several sec-alcohols but its low reactivity makes it non-optimal for use at room temperature (rt). Optimisation of the conditions for conducting KRs at rt using a previously described catalyst (containing a phenyl blocking group) at the 1 mol% level indicates that PPh3 (1 equiv) is beneficial for enantioselectivity and allows KR of (±)-1-(naphthyl)ethanol in less than 30 min with s>15 (i.e., ～40% recovered alcohol with >95% ee). These conditions constitute a convenient and practical method for rapid KR of sec-alcohols and are anticipated to facilitate a detailed kinetic study of this catalytic manifold by calorimetry.
Single-step preparation of a 4-(dimethylamino)pyridine analogue bearing a sulfoxide as new chiral inducer. Preliminary evaluation as nucleophilic catalyst
Poisson, Thomas,Penhoat, Ma?l,Papamica?l, Cyril,Dupas, Georges,Dalla, Vincent,Marsais, Francis,Levacher, Vincent
, p. 2285 - 2288 (2007/10/03)
A one-step synthesis of a new chiral DMAP-1a equivalent is reported by bromine-magnesium exchange reaction of the 3-bromo-4-(dimethylamino)pyridine (2). The chiral sulfoxide appendage is introduced by trapping the resulting Grignard intermediate with (1R,
