41720-55-2Relevant academic research and scientific papers
Enantioselective Bio-Hydrolysis of Geranyl-Derived rac-Epoxides: A Chemoenzymatic Route to trans-Furanoid Linalool Oxide
van Lint, Matthijs J.,Gümüs, Aysegül,Ruijter, Eelco,Faber, Kurt,Orru, Romano V. A.,Hall, Mélanie
, p. 813 - 825 (2019)
In contrast to many chemical dihydroxylation methods, enzymatic epoxide hydrolysis provides an environmentally benign route to vicinal diols, which are important intermediates in the synthesis of fine chemicals and pharmaceuticals. Using epoxide hydrolases, enantiopure diols are accessible under mild conditions. In order to assess the selectivity of epoxide hydrolases on geraniol-derived oxiranes, a range of derivatives were screened against a large variety of enzyme preparations. For nearly all substrates, a matching hydrolase with excellent enantioselectivity (≥95% ee) could be found. In addition, a chemoenzymatic approach for the stereoselective synthesis of furanoid linalool oxide was developed. Combination of enzymatic enantioselective hydrolysis with stereoselective Tsuji-Trost reaction granted diastereoselective access to trans-(2R,5R)-configured linalool oxide with high diastereomeric and enantiomeric excess (97% de and 97% ee). (Figure presented.).
One-pot synthesis at room temperature of epoxides and linalool derivative pyrans in monolacunary Na7PW11O39-catalyzed oxidation reactions by hydrogen peroxide
Da Silva, Márcio J.,Teixeira, Milena Galdino,Vilanculo, Castelo B.,Villarreal, Jesus Avendano
, p. 7691 - 7697 (2020/03/10)
In this work, we describe a new one-pot synthesis route of valuable linalool oxidation derivatives (i.e., 2-(5-methyl-5-vinyltetrahydrofuran-2-yl propan-2-ol) (1a)), 2,2,6-trimethyl-6-vinyltetrahydro-2H-pyran-3-ol (1b) and diepoxide (1c), using a green oxidant (i.e., hydrogen peroxide) under mild conditions (i.e., room temperature). Lacunar Keggin heteropolyacid salts were the catalysts investigated in this reaction. Among them, Na7PW11O39 was the most active and selective toward oxidation products. All the catalysts were characterized by FT-IR, TG/DSC, BET, XRD analyses and potentiometric titration. The main reaction parameters were assessed. Special attention was dedicated to correlating the composition and properties of the catalysts and their activity.
A protecting-group-free synthesis of arbusculone, andirolactone, pinnatolide, ipomolactone, cyclocapitelline and isocyclocapitelline
Gajula, Srinivas,Madhu, Madasu,Chintakrinda, Suresh Kumar,Yadav,Mohapatra, Debendra K.
, p. 4172 - 4175 (2018/10/20)
A general approach for a collective synthesis of natural products containing substituted THF ring is described. In this paper, Arbusculone, a small molecule natural product accomplished using a short route, is used as the key intermediate to achieve the total synthesis of Andirolactone, Pinnatolide, Ipomolactone, Cyclocapitelline, Isocyclocapitelline and their two isomers in less than ten steps. The present effort highlights protecting-group-free total syntheses and the shortest route to access these natural products from commercially available cheap starting materials.
Cis-2,6-Bis-(methanolate)-piperidine oxovanadium(V) complexes as catalysts for oxidative alkenol cyclization by tert-butyl hydroperoxide
D?nges, Maike,Amberg, Matthias,Stapf, Georg,Kelm, Harald,Bergstr??er, Uwe,Hartung, Jens
, p. 120 - 134 (2014/07/08)
cis-2,6-Bis-(methanolate)-piperidine oxovanadium(V) complexes are Lewis acids able to catalyze oxidative cyclization of alkenols by tert-butyl hydroperoxide (TBHP). Terminal dimethyl-substituted (prenyl-type) 4-pentenols bearing an alkyl or a phenyl group in position 1 afford under such conditions 2,5-cis-derivatives of 2-(tetrahydrofuran-2-yl)-2-propanol as major and tetrahydropyran-3-ols as minor products (four examples). Oxidizing 1-phenyl-6-methylhept-5-en-1-ol yields a 75/25-mixture of the derived 2-(tetrahydropyran-2-yl)-2-propanol and an oxepan-3-ol, whereas 2-propenols give epoxides in up to 94% yield. Epoxidizing geraniol by TBHP in the presence of a vanadium catalyst prepared from (2S,6R)-2-diphenylmethanol-6- hydroxymethylpiperidine occurs enantioselectively. Highfield shifts of vanadium-51 resonances upon adding alkyl hydroperoxides to solutions of cis-2,6-bis-(methanolate)-piperidine vanadium(V) complexes point to vanadium(V) tert-butyl peroxy complex formation as key step for activating peroxides.
Biotransformations of terpenes by fungi from amazonian Citrus plants
Moreno Rueda, Maria Gabriela,Guerrini, Alessandra,Giovannini, Pier Paolo,Medici, Alessandro,Grandini, Alessandro,Sacchetti, Gianni,Pedrini, Paola
, p. 1909 - 1919 (2013/11/06)
The biotransformations of (RS)-linalool (1), (S)-citronellal (2), and sabinene (3) with fungi isolated from the epicarp of fruits of Citrus genus of the Amazonian forest (i.e., C. limon, C. aurantifolia, C. aurantium, and C. paradisiaca) are reported. The
Two-step, stereoselective synthesis of linalyl oxides by asymmetric allylic O-alkylation
Wan, Kanny K.,Litz, Jonathan P.,Vosburg, David A.
experimental part, p. 2425 - 2428 (2011/02/16)
Each of the four tetrahydrofuran linalyl oxides was prepared by a Sharpless asymmetric dihydroxylation of geranyl acetate with AD-mix-α or AD-mix-β, followed by a stereoselective palladium-mediated cyclization using the chiral ligand C3-TunePhos.
Fungal biotransformation of (±)-linalool
Mirata, Marco-Antonio,Wuest, Matthias,Mosandl, Armin,Schrader, Jens
, p. 3287 - 3296 (2008/09/20)
The biotransformation of (±)-linalool was investigated by screening 19 fungi. Product accumulation was enhanced by substrate feeding and, for the first time, lilac aldehydes and lilac alcohols were identified as fungal biotransformation byproduct using SPME-GC-MS headspace analysis. Aspergillus niger DSM 821, Botrytis cinerea 5901/02, and B. cinerea 02/FBII/2.1 produced different isomers of lilac aldehyde and lilac alcohol from linalool via 8-hydroxylinalool as postulated intermediate. Linalool oxides and 8-hydroxylinalool were the major products of fungal (±)-linalool biotransformations. Furanoid trans-(2R,5R)- and cis-(2S,5R)-linalool oxide as well as pyranoid trans-(2R,5S)- and cis-(2S, 5S)-linalool oxide were identified as the main stereoisomers with (3S,6S)-6,7-epoxylinalool and (3R,6S)-6,7-epoxylinalool as postulated key intermediates of fungal (±)-linalool oxyfunctionalization, respectively. With a conversion yield close to 100% and a productivity of 120 mg/L·day linalool oxides, Corynespora cassiicola DSM 62485 was identified as a novel highly stereoselective linalool transforming biocatalyst showing the highest productivity reported so far.
Vanadium(V)-catalyzed oxidation of (3R)-linalool - The selective formation of furanoid linalool oxides and their conversion into isocyclocapitelline derivatives
Hartung, Jens,Drees, Simone,Geiss, Barbara,Schmidt, Philipp
, p. 223 - 226 (2007/10/03)
Oxidation of (3R)-linalool (2) with tert-butyl hydroperoxide (TBHP) occurs at the 6,7-position to selectively afford linalool oxide cis-1, if catalyzed by vanadium(V) Schiff base complexes 4. Substituted tetrahydrofuran cis-1 and its isomer trans-1 served
(Schiff-base)vanadium(v) complex-catalyzed oxidations of substituted bis(homoallylic) alcohols - Stereoselective synthesis of functionalized tetrahydrofurans
Hartung, Jens,Drees, Simone,Greb, Marco,Schmidt, Philipp,Svoboda, Ingrid,Fuess, Hartmut,Murso, Alexander,Stalke, Dietmar
, p. 2388 - 2408 (2007/10/03)
Vanadium(v) complexes 4 have been prepared from tridentate Schiff-base ligands 3 and VO(OEt)3. All vanadium(v) compounds were characterized (IR, UV/Vis, and 51V NMR spectroscopy, and in selected examples by X-ray diffraction analysis) and were applied as oxidation catalysts for the stereoselective synthesis of functionalized tetrahydrofurans 2 starting from substituted bis(homoallylic) alcohols 1 (mono- or trisubstituted C-C double bonds). Oxidation of secondary or tertiary 1-alkyl-, 1-vinyl-, or 1-phenyl-substituted 5,5-dimethyl-4-penten-1-ols under optimized conditions [TBHP as primary oxidant and 1,2-(amino)indanol-derived vanadium(v) reagent 4g as catalyst] provided 2,5-cis-configured tetrahydrofurans in synthetically useful yields and diastereoselectivities (22-96% de). On the other hand, trans-disubstituted oxolanes (62%-96 de) were obtained from oxidations of 2- or 3-alkyl- and 2- or 3-phenyl-substituted 5,5-dimethyl-4-penten-1-ols bis(homoallylic) allyhc) alcohols. Treatment of 4-penten-1-ols (i.e. substrates with monosubstituted olefinic π-bonds) with TBHP and catalytic amounts of vanadium(v) complex 4g furnished trans-disubstituted tetrahydrofurans as major products (20-96% de), no matter whether an alkyl or a phenyl substituent was located in position 1, 2, or 3 of the alkenol chain. The mechanism of this reaction has been investigated in detail. Based on results from 51V NMR spectroscopy and competition kinetics, it proceeds by a transition metal-peroxy pathway. In an initial step, TBHP coordinates to, for example, N-(2-oxidophenyl)salicylideniminato-derived vanadium complex 4a. Subsequent alkenol binding gives rise to a "loaded" vanadium(v) peroxy complex (e.g. 60) which facilitates diastereoselective oxygen transfer, presumably onto a coordinated substrate. This step leads to the formation of functionalized tetrahydrofurans as major products. TBHP binding to the remaining vanadium(v) complex then allows a regeneration of the active oxidant, for example peroxy complex 57. The origin of the observed diastereoselectivity in this oxidation has been studied in an independent stereochemical analysis. Thus, diastereomerically enriched epoxy alcohol (1R,4R)-10 was prepared. Its treatment with 1,2-(amino)indanol-derived vanadium complex 4g affords a 91:9 mixture of cis-2-(1-hydroxy-1-methylethyl)-5-(phenyl)tetrahydrofuran (cis-6) and cis-2,2-dimethyl-6-(phenyl)tetrahydropyran-3-ol (cis-7). Similarly, a 39:61 mixture of heterocycles trans-6 and trans-7 was obtained from epoxy alcohol (1S,4R)-10, if treated with Lewis acid 4g. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).
From rational octahedron design to reticulation serendipity. A thermally stable rare earth polymeric disulfonate family with CdI2-like structure, bifunctional catalysis and optical properties
Snejko, Natalia,Cascales, Concepcion,Gomez-Lor, Berta,Gutierrez-Puebla, Enrique,Iglesias, Marta,Ruiz-Valero, Caridad,Monge, M. Angeles
, p. 1366 - 1367 (2007/10/03)
A new family of lanthanide disulfonates Ln(OH)(NDS)- (H2O), (Ln = La, Pr and Nd; NDS = 1,5-naphthalenedisulfonate) was designed and hydrothermally synthesized; this is the first example of a disulfonate ligand coordinated to six different Ln atoms; these materials, with high thermal stability, act as active and selective bifunctional catalysts in oxidation and epoxide ring opening; strong luminescence from the optically active Nd center was observed.
