62413-47-2Relevant academic research and scientific papers
Regio- and stereoselective reduction of trans-4-phenylbut-3-en-2-one using carrot, celeriac, and beetroot enzyme systems in an organic solvent
Majewska, Ewa,Koz?owska, Mariola
, p. 6331 - 6332 (2013)
(S)-trans-4-Phenylbut-3-en-2-ol has been obtained in excellent yields and with high enantiomeric excess in the reduction of trans-4-phenylbut-3-en-2-one using the comminuted roots of carrot (Daucus carota L.), celeriac (Apium graveolens L. var. rapaceum),
Regioselective asymmetric bioreduction of trans-4-phenylbut-3-en-2-one by whole-cell of Weissella cibaria N9 biocatalyst
Kalay, Erbay,?ahin, Engin
, p. 535 - 542 (2021)
There is a considerable interest in the asymmetric production of chiral allylic alcohols, the main building blocks of many functional molecules. The asymmetric reduction of α,β-unsaturated ketones is difficult with traditional chemical protocols in a regi
Self-Assembling All-Enzyme Hydrogels for Flow Biocatalysis
Peschke, Theo,Bitterwolf, Patrick,Gallus, Sabrina,Hu, Yong,Oelschlaeger, Claude,Willenbacher, Norbert,Rabe, Kersten S.,Niemeyer, Christof M.
, p. 17028 - 17032 (2018)
Continuous flow biocatalysis is an emerging field of industrial biotechnology that uses enzymes immobilized in flow channels for the production of value-added chemicals. We describe the construction of self-assembling all-enzyme hydrogels that are compris
Cobalt-Catalyzed Regio- and Enantioselective Markovnikov 1,2-Hydrosilylation of Conjugated Dienes
Wen, Huanan,Wang, Kuan,Zhang, Yanlu,Liu, Guixia,Huang, Zheng
, p. 1612 - 1618 (2019)
The asymmetric 1,2-Markovnikov hydrosilylation of conjugated dienes with primary silanes catalyzed by a quinoline-oxazoline cobalt complex has been described. This protocol provides an efficient approach to chiral allyl dihydrosilanes with high regioselectivity and enantioselectivity (up to 96% ee). The catalyst system is effective for a wide array of conjugated dienes, including mono- and 1,2-disubstituted dienes with aryl and/or alkyl substituents. Further, the products are applied to the synthesis of polyorganosiloxanes (organo-silicone copolymers) containing side chains of enantioenriched allylic functionalities using a pyridine-oxazoline cobalt-catalyzed step-growth polymerization with terephthalaldehyde. The result of a deuterium-labeling experiment involving the reaction of PhSiD3 and 1,3-pentadiene suggests that the hydrosilylation most likely proceeds through a modified Chalk-Harrod mechanism involving the 1,2-insertion of the terminal double bond of the diene into the Co-Si bond.
Dramatic titanium alkoxide effect in the catalytic enantioselective addition of dialkylzincs to aldehydes
Nowotny, Stefan,Vettel, Stephan,Knochel, Paul
, p. 4539 - 4540 (1994)
The use of Ti(Ot-Bu)4, or related bulky titanium (IV) alkoxides, as cocatalysts instead of Ti(Oi-Pr)4 in the enantioselective addition of dimethylzinc to aldehydes in the prescence of the catalyst 2 (8 mol%) leads to a dramatic impro
Novel hydrido-ruthenium(II) complexes with histidine derivatives and their application in the hydrogenation of ketones
Sui-Seng, Christine,Hadzovic, Alen,Lough, Alan J.,Morris, Robert H.
, p. 2536 - 2541 (2007)
The complexes RuHCl((R)-binap)(L-NH2) with L-NH2 = (S)-histidine-Me-ester (1), histamine (3), (S)-histidinol (4) or 1-Me-(S)-histidine-Me-ester (5), and RuHCl((S)-binap)(L-NH2) with L-NH2 = (S)-histidine-Me-ester (2) have been prepared in 60-81% overall yields in a one-pot, three-step procedure from the precursor RuCl 2(PPh3)3. Their octahedral structures with hydride trans to chloride were deduced from their NMR spectra and confirmed by the results of a single crystal X-ray diffraction study for complex 3. Under H2 and in the presence of KOtBu, complexes 1-5 in 2-propanol form moderately active catalyst precursors for the asymmetric hydrogenation of acetophenone to 1-phenylethanol. Complex 5 is more active and enantioselective than complexes 1-4, allowing complete conversion to 1-phenylethanol in 46% e.e. (R) in 72 h at 20 °C under 1 MPa of H2 with substrate: catalyst: base = 2000: 1: 30. Complex 5, when activated, also catalyzes the hydrogenation of trans-4-phenyl-3-buten-2-one to exclusively the allyl alcohol 4-phenyl-3-buten-2-ol under 2.7 MPa of H2 at 50°C in 2-propanol. This selectivity for CO versus CC hydrogenation is consistent with a mechanism involving the outer sphere transfer of hydride and proton to the polar bond. Further extensions to complexes with peptides with N-terminal histidine groups appear feasible on the basis of the current work. The Royal Society of Chemistry 2007.
Nickel-Catalyzed Enantioselective Hydroboration of Vinylarenes
Tran, Hai N.,Stanley, Levi M.
supporting information, p. 395 - 399 (2021/12/27)
The enantioselective hydroboration of vinylarenes catalyzed by a chiral, nonracemic nickel catalyst is presented as a facile method for generating chiral benzylic boronate esters. Various vinylarenes react with bis(pinacolato)diboron (B2pin2) in the presence of MeOH as a hydride source to form chiral boronate esters in up to 92% yield with up to 94% ee. The use of anhydrous Me4NF to activate B2pin2 is crucial for ensuring fast transmetalation to achieve high enantioselectivities.
Highly Active Cooperative Lewis Acid—Ammonium Salt Catalyst for the Enantioselective Hydroboration of Ketones
Titze, Marvin,Heitk?mper, Juliane,Junge, Thorsten,K?stner, Johannes,Peters, René
supporting information, p. 5544 - 5553 (2021/02/05)
Enantiopure secondary alcohols are fundamental high-value synthetic building blocks. One of the most attractive ways to get access to this compound class is the catalytic hydroboration. We describe a new concept for this reaction type that allowed for exceptional catalytic turnover numbers (up to 15 400), which were increased by around 1.5–3 orders of magnitude compared to the most active catalysts previously reported. In our concept an aprotic ammonium halide moiety cooperates with an oxophilic Lewis acid within the same catalyst molecule. Control experiments reveal that both catalytic centers are essential for the observed activity. Kinetic, spectroscopic and computational studies show that the hydride transfer is rate limiting and proceeds via a concerted mechanism, in which hydride at Boron is continuously displaced by iodide, reminiscent to an SN2 reaction. The catalyst, which is accessible in high yields in few steps, was found to be stable during catalysis, readily recyclable and could be reused 10 times still efficiently working.
Manganese catalyzed enantio- and regioselective hydrogenation of α,β-unsaturated ketones using an imidazole-based chiral PNN tridentate ligand
Wang, Ze,Zhao, Xianghua,Huang, An,Yang, Zehui,Cheng, Yuqi,Chen, Jiachen,Ling, Fei,Zhong, Weihui
supporting information, (2021/09/22)
The enantioselective 1,2-reduction of α,β-unsaturated ketones has been achieved using a chiral pincer Mn catalyst. A series of PNN tridentate ligands containing benzimidazole groups were designed with ferrocene as the backbone, which coordinated with Mn t
Mn(i) phosphine-amino-phosphinites: a highly modular class of pincer complexes for enantioselective transfer hydrogenation of aryl-alkyl ketones
Jayaprakash, Harikrishnan
supporting information, p. 14115 - 14119 (2021/10/25)
A series of Mn(i) catalysts with readily accessible and more π-accepting phosphine-amino-phosphinite (P′(O)N(H)P) pincer ligands have been explored for the asymmetric transfer hydrogenation of aryl-alkyl ketones which led to good to high enantioselectivities (up to 98%) compared to other reported Mn-based catalysts for such reactions. The easy tunability of the chiral backbone and the phosphine moieties makes P′(O)N(H)P an alternative ligand framework to the well-known PNP-type pincers.
