590417-83-7Relevant academic research and scientific papers
Markovnikov Wacker-Tsuji Oxidation of Allyl(hetero)arenes and Application in a One-Pot Photo-Metal-Biocatalytic Approach to Enantioenriched Amines and Alcohols
Albarrán-Velo, Jesús,Gotor-Fernández, Vicente,Lavandera, Iván
, p. 4096 - 4108 (2021/08/19)
The Wacker-Tsuji aerobic oxidation of various allyl(hetero)arenes under photocatalytic conditions to form the corresponding methyl ketones is presented. By using a palladium complex [PdCl2(MeCN)2] and the photosensitizer [Acr-Mes]ClO4 in aqueous medium and at room temperature, and by simple irradiation with blue led light, the desired carbonyl compounds were synthesized with high conversions (>80%) and excellent selectivities (>90%). The key process was the transient formation of Pd nanoparticles that can activate oxygen, thus recycling the Pd(II) species necessary in the Wacker oxidative reaction. While light irradiation was strictly mandatory, the addition of the photocatalyst improved the reaction selectivity, due to the formation of the starting allyl(hetero)arene from some of the obtained by-products, thus entering back in the Wacker-Tsuji catalytic cycle. Once optimized, the oxidation reaction was combined in a one-pot two-step sequential protocol with an enzymatic transformation. Depending on the biocatalyst employed, i. e. an amine transaminase or an alcohol dehydrogenase, the corresponding (R)- and (S)-1-arylpropan-2-amines or 1-arylpropan-2-ols, respectively, could be synthesized in most cases with high yields (>70%) and in enantiopure form. Finally, an application of this photo-metal-biocatalytic strategy has been demonstrated in order to get access in a straightforward manner to selegiline, an anti-Parkinson drug. (Figure presented.).
A General Regioselective Synthesis of Alcohols by Cobalt-Catalyzed Hydrogenation of Epoxides
Beller, Matthias,Junge, Kathrin,Leischner, Thomas,Li, Wu,Liu, Weiping
supporting information, p. 11321 - 11324 (2020/05/16)
A straightforward methodology for the synthesis of anti-Markovnikov-type alcohols is presented. By using a specific cobalt triphos complex in the presence of Zn(OTf)2 as an additive, the hydrogenation of epoxides proceeds with high yields and selectivities. The described protocol shows a broad substrate scope, including multi-substituted internal and terminal epoxides, as well as a good functional-group tolerance. Various natural-product derivatives, including steroids, terpenoids, and sesquiterpenoids, gave access to the corresponding alcohols in moderate-to-excellent yields.
Facile Protocol for Catalytic Frustrated Lewis Pair Hydrogenation and Reductive Deoxygenation of Ketones and Aldehydes
Mahdi, Tayseer,Stephan, Douglas W.
supporting information, p. 8511 - 8514 (2015/11/27)
A series of ketones and aldehydes are reduced in toluene under H2 in the presence of 5 mol % B(C6F5)3 and either cyclodextrin or molecular sieves affording a facile metal-free protocol for reduction to alcohols. Similar treatment of aryl ketones resulted in metal-free deoxygenation yielding aromatic hydrocarbons.
Enabling catalytic ketone hydrogenation by frustrated lewis pairs
Mahdi, Tayseer,Stephan, Douglas W.
supporting information, p. 15809 - 15812 (2015/02/19)
Hydrogenation of alkyl and aryl ketones using H2 is catalytically achieved in 18 examples using 5 mol % B(C6F5)3 in an ethereal solvent. In these cases the borane and ether behave as a frustrated Lewis pair to activate H2 and effect the reduction.
Ether-directed ortho-C-H olefination with a palladium(II)/monoprotected amino acid catalyst
Li, Gang,Leow, Dasheng,Wan, Li,Yu, Jin-Quan
supporting information, p. 1245 - 1247 (2013/03/13)
Weak coordination is powerful! A PdII-catalyzed olefination of ortho-C-H bonds of arenes directed by weakly coordinating ethers is developed by using monoprotected amino acid (MPAA) ligands. This finding provides a method for chemically modifying ethers, which are abundant in natural products and drug molecules. HFIP=hexafluoroisopropanol. Copyright
Screening on the use of Kluyveromyces marxianus CBS 6556 growing cells as enantioselective biocatalysts for ketone reductions
Vitale, Paola,Perna, Filippo Maria,Perrone, Maria Grazia,Scilimati, Antonio
body text, p. 1985 - 1993 (2012/03/22)
The versatility of Kluyveromyces marxianus CBS 6556 growing cells in the enantioselective reduction of ketone functionalities to the corresponding alcohols was exploited. In particular, methyl ketones were reduced to (S)-alcohols with ees of up to 96%. Longer chain alkyl ketones afforded, under the same experimental condition, (R)-alcohols with an ee of up to 84%. Interestingly, carbon-carbon double and the triple bonds can also be reduced in the presence of Kluyveromyces marxianus CBS 6556 yeast. A cyclic ketone, such as 2-tetralone, was also quantitatively reduced to its corresponding (S)-alcohol with ee = 76%.
Straightforward synthesis of enantiopure 2,3-dihydrobenzofurans by a sequential stereoselective biotransformation and chemical intramolecular cyclization
Mangas-Sanchez, Juan,Busto, Eduardo,Gotor-Fernandez, Vicente,Gotor, Vicente
supporting information; experimental part, p. 3498 - 3501 (2010/10/20)
(Equation Presented). A new family of optically active 2,3- dihydrobenzofurans has been prepared by a simple chemoenzymatic asymmetric strategy. This synthetic approach is based on the combination of a lipase-mediated kinetic resolution of 1-aryl-2-propanols or bioreduction of the corresponding ketones followed by an intramolecular cyclization reaction. These novel compounds have been prepared in enantiopure form and in good overall yield through a straightforward route.
Novel phosphine compound, transition metal complex containing the same phosphine compound as ligand and asymmetric synthesis catalyst containing the complex
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, (2008/06/13)
A phosphine compound of formula (1) and a phosphine compound of formula (2) a transition metal complex having the phosphine compound as a ligand and a catalyst for asymmetric hydrogenation including the transition metal complex.
