15541-26-1Relevant articles and documents
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
supporting information, 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.).
Ortho-directed functionalization of arenes using magnesate bases
Bellamy, Estelle,Bayh, Omar,Hoarau, Christophe,Trecourt, Francois,Queguiner, Guy,Marsais, Francis
supporting information; experimental part, p. 7043 - 7045 (2010/11/02)
Ortho-directed functionalisation of arenes using lithium alkylmagnesate bases were achieved, demonstrating the potential use of arylmagnesates as suitable arylanions, without a further transmetallation step, for challenging functionalizations such as fluorination, hydroxylation, arylation, vinylation and alkylation through epoxide ring-opening.
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.
Stereoselective production of (S)-1-aralkyl- and 1-arylethanols by freshly harvested and lyophilized yeast cells
Erdelyi, Balazs,Szabo, Antal,Seres, Gabor,Birincsik, Laszlo,Ivanics, Jozsef,Szatzker, Gabor,Poppe, Laszlo
, p. 268 - 274 (2007/10/03)
Substituted (S)-1-phenyl- 2a-h and (S)-1-benzyl-propan-2-ols 4a and b, and (S)-1-phenylethanol 6 were produced from prochiral ketones 1a-h, 3a,b and 5 by reductions with freshly harvested Zygosaccharomyces rouxii and Debaryomyces hansenii cells. The bioreductions were also performed by lyophilized cells. Comparison of the secondary alcohols from the bioreductions 2b-e,g,h and 4a and authentic (S)-alcohols (S)-2b-e,g,h and (S)-4a synthesized from enantiopure (S)-methyloxirane 7 proved the absolute configuration of the products.
Novel photohydration of non-conjugated aryl/olefin bichromophores within cyclodextrin cavities
Benali,Jimenez,Miranda,Tormos
, p. 2328 - 2329 (2007/10/03)
Cyclodextrin media are used to achieve photochemical water addition to isolated, acyclic double bonds via intramolecular interaction with excited arenes.
The role of neighbouring group participation in TTF-mediated 'radical- polar crossover' reactions: Trapping of aliphatic radicals by TTF+.
Bashir, Nadeem,Murphy, John A.
, p. 627 - 628 (2007/10/03)
Trapping of secondary alkyl radicals with tetrathiafulvalenium tetrafluoroborate (TTF+.BF4-) leads to S-alkyltetrathiafulvalenium tetrafluoroborate salts; the solvolysis of such salts is critically dependent on the presence of appropriately sited neighbouring groups.