1736-67-0Relevant articles and documents
High-Level Production of Phenylacetaldehyde using Fusion-Tagged Styrene Oxide Isomerase
Choo, Joel P. S.,Kammerer, Richard A.,Li, Xiaodan,Li, Zhi
, p. 1714 - 1721 (2021/02/12)
An order-of-magnitude improvement in the production of phenylacetaldehyde to 3.37 M (405 g L?1) from the enzymatic isomerisation of styrene oxide was achieved. A small ubiquitin-related modifier (SUMO) tag increases the productivity of the whole-cell biocatalytic system by enhancing the expression of active membrane-bound styrene oxide isomerase (SOI) while retaining enzyme catalytic efficiency and broad natural substrate scope. The isomerisation was performed by using Escherichia coli expressing SUMO-tagged SOI in an organic-aqueous biphasic system to yield 96% of phenylacetaldehyde. (Figure presented.).
Regioselective, Diastereoselective, and Enantioselective One-Pot Tandem Reaction Based on an in Situ Formed Reductant: Preparation of 2,3-Disubstituted 1,5-Benzodiazepine
Yang, Gao-Feng,Li, Guang-Xun,Huang, Jin,Fu, Ding-Qiang,Nie, Xiao-Kang,Cui, Xin,Zhao, Jin-Zhong,Tang, Zhuo
, p. 5110 - 5119 (2021/04/12)
The 1,5-benzodiazepines are important skeletons frequently contained in medicinal chemistry. Herein, we described an unexpected tandem cyclization/transfer hydrogenation reaction for obtaining chiral 2,3-disubstituted 1,5-benzodiazepines. The enolizable aryl aldehydes were chosen as substrates to react with symmetric and unsymmetric o-phenylenediamines. The unforeseen tandem reaction occurred among many possible latent side reactions under chiral phosphoric acid catalysis and affords the corresponding products in moderate yields and regioselectivities, good diastereoselectivities, and enantiomeric ratio (up to 99:1).
Rhodium-Catalyzed β-Dehydroborylation of Silyl Enol Ethers: Access to Highly Functionalized Enolates
Li, Jie,Li, Ruoling,Yang, Wen,Zhao, Pei,Zhao, Wanxiang
supporting information, p. 9580 - 9585 (2021/12/14)
An efficient rhodium-catalyzed β-dehydroborylation of aldehyde-derived silyl enol ethers (SEEs) with bis(pinacolato)diboron (B2pin2) is disclosed. The borylation reactions proceeded well with alkyl- and aryl-substituted SEEs, affording a wide array of valuable functionalized β-boryl silyl enolates with high efficiency and excellent stereoselectivity. Moreover, the borylated products, through versatile carbon–boron bond transformations, were readily converted into diverse synthetically useful molecules, including α-hydroxy ketones, functionalized SEEs, and gem-difunctionalized aldehydes.
Aerobic epoxidation of styrene over Zr-based metal-organic framework encapsulated transition metal substituted phosphomolybdic acid
Hu, Dianwen,Song, Xiaojing,Zhang, Hao,Chang, Xinyu,Zhao, Chen,Jia, Mingjun
, (2021/04/19)
Catalytic epoxidation of styrene with molecular oxygen is regarded as an eco-friendly alternative to producing industrially important chemical of styrene oxide (STO). Recent efforts have been focused on developing highly active and stable heterogeneous catalysts with high STO selectivity for the aerobic epoxidation of styrene. Herein, a series of transition metal monosubstituted heteropolyacid compounds (TM-HPAs), such as Fe, Co, Ni or Cu-monosubstituted HPA, were encapsulated in UiO-66 frameworks (denoted as TM-HPA@UiO-66) by direct solvothermal method, and their catalytic properties were investigated for the aerobic epoxidation of styrene with aldehydes as co-reductants. Among them, Co-HPA@UiO-66 showed relatively high catalytic activity, stability and epoxidation selectivity at very mild conditions (313 K, ambient pressure), that can achieve 82 % selectivity to STO under a styrene conversion of 96 % with air as oxidant and pivalaldehyde (PIA) as co-reductant. In addition, the hybrid composite catalyst can also efficiently catalyze the aerobic epoxidation of a variety of styrene derivatives. The monosubstituted Co atoms in Co-HPA@UiO-66 are the main active sites for the aerobic epoxidation of styrene with O2/PIA, which can efficiently converting styrene to the corresponding epoxide through the activation of the in-situ generated acylperoxy radical intermediate.
Manganese and rhenium-catalyzed selective reduction of esters to aldehydes with hydrosilanes
Wei, Duo,Buhaibeh, Ruqaya,Canac, Yves,Sortais, Jean-Baptiste
, p. 11617 - 11620 (2020/10/19)
The selective reduction of esters to aldehydes, via the formation of stable alkyl silyl acetals, was, for the first time, achieved with both manganese, -Mn2(CO)10- and rhenium -Re2(CO)10- catalysts in the presence of triethylsilane as reductant. These two methods provide a direct access to a large variety of aliphatic and aromatic alkyl silyl acetals (30 examples) and to the corresponding aldehydes (13 examples) upon hydrolysis. The reactions proceeded in excellent yields and high selectivity at room temperature under photo-irradiation conditions (LED, 365 nm, 40 W, 9 h).
Deoxygenation of Epoxides with Carbon Monoxide
Maulbetsch, Theo,Jürgens, Eva,Kunz, Doris
, p. 10634 - 10640 (2020/07/30)
The use of carbon monoxide as a direct reducing agent for the deoxygenation of terminal and internal epoxides to the respective olefins is presented. This reaction is homogeneously catalyzed by a carbonyl pincer-iridium(I) complex in combination with a Lewis acid co-catalyst to achieve a pre-activation of the epoxide substrate, as well as the elimination of CO2 from a γ-2-iridabutyrolactone intermediate. Especially terminal alkyl epoxides react smoothly and without significant isomerization to the internal olefins under CO atmosphere in benzene or toluene at 80–120 °C. Detailed investigations reveal a substrate-dependent change in the mechanism for the epoxide C?O bond activation between an oxidative addition under retention of the configuration and an SN2 reaction that leads to an inversion of the configuration.
α-Amino Diphenyl Phosphonates as Novel Inhibitors of Escherichia coli ClpP Protease
Moreno-Cinos, Carlos,Sassetti, Elisa,Salado, Irene G.,Witt, Gesa,Benramdane, Siham,Reinhardt, Laura,Cruz, Cristina D.,Joossens, Jurgen,Van Der Veken, Pieter,Br?tz-Oesterhelt, Heike,Tammela, P?ivi,Winterhalter, Mathias,Gribbon, Philip,Windshügel, Bj?rn,Augustyns, Koen
, p. 774 - 797 (2019/01/30)
Increased Gram-negative bacteria resistance to antibiotics is becoming a global problem, and new classes of antibiotics with novel mechanisms of action are required. The caseinolytic protease subunit P (ClpP) is a serine protease conserved among bacteria that is considered as an interesting drug target. ClpP function is involved in protein turnover and homeostasis, stress response, and virulence among other processes. The focus of this study was to identify new inhibitors of Escherichia coli ClpP and to understand their mode of action. A focused library of serine protease inhibitors based on diaryl phosphonate warheads was tested for ClpP inhibition, and a chemical exploration around the hit compounds was conducted. Altogether, 14 new potent inhibitors of E. coli ClpP were identified. Compounds 85 and 92 emerged as most interesting compounds from this study due to their potency and, respectively, to its moderate but consistent antibacterial properties as well as the favorable cytotoxicity profile.
Stereoselective Synthesis of Vinylboronates by Rh-Catalyzed Borylation of Stereoisomeric Mixtures
Li, Shenhuan,Li, Jie,Xia, Tianlai,Zhao, Wanxiang
supporting information, p. 462 - 468 (2019/03/28)
The stereoselective preparation of vinylboronates via rhodium-catalyzed borylation of E/Z mixtures of vinyl actetates is described, and this method was also extended to synthesis of vinyldiboronates. These transformations feature high functional group compatibility and mild reaction conditions. Control experiments support a mechanism that involved a Rh-catalyzed borylation-isomerization sequence. The isomerization of (Z)-vinylboronates to (E)-isomers was also demonstrated.
Facile Access to Challenging ortho-Terphenyls via Merging Two Multi-Step Domino Reactions in One-Pot: A Joint Experimental/Theoretical Study
Grau, Benedikt W.,B?nisch, Simon,Neuhauser, Alexander,Hampel, Frank,G?rling, Andreas,Tsogoeva, Svetlana B.
, p. 3982 - 3992 (2019/08/08)
ortho-Terphenyls are of high interest for medicinal chemistry and materials science, but they are difficult to access. Herein, we demonstrate a straightforward and sustainable synthesis of highly functionalized ortho-terphenyls via joining an organocatalyzed two-step domino reaction (Knoevenagel/vinylogous Michael) with a DABCO/CuBr2 co-catalyzed three-step domino reaction (cyclization/tautomerization/aromatization) in a one-pot process. Overcoming necessity to isolate intermediate products leads to a reduction of energy, costs and waste for a broad scope of reactions. DFT calculations have been performed to investigate the thermodynamics of this one-pot process towards ortho-terphenyls and to study the reaction profile of the vinylogous Michael reaction under inclusion of solvent effects. Role of London dispersion forces in this transformation has been elucidated. It is shown that reaction kinetics and thermodynamics are slightly influenced by dispersion interactions. Furthermore, the addition of dispersion energy donors leads to small changes of reaction energies in some cases.
Synthesis and evaluation of 1,3,4-oxadiazole derivatives for development as broad-spectrum antibiotics
Tresse, Cédric,Radigue, Richard,Gomes Von Borowski, Rafael,Thepaut, Marion,Hanh Le, Hong,Demay, Fanny,Georgeault, Sylvie,Dhalluin, Anne,Trautwetter, Annie,Ermel, Gwennola,Blanco, Carlos,van de Weghe, Pierre,Jean, Micka?l,Giard, Jean-Christophe,Gillet, Reynald
, (2019/09/18)
The reality and intensity of antibiotic resistance in pathogenic bacteria calls for the rapid development of new antimicrobial drugs. In bacteria, trans-translation is the primary quality control mechanism for rescuing ribosomes arrested during translation. Because trans-translation is absent in eukaryotes but necessary to avoid ribosomal stalling and therefore essential for bacterial survival, it is a promising target either for novel antibiotics or for improving the activities of the protein synthesis inhibitors already in use. Oxadiazole derivatives display strong bactericidal activity against a large number of bacteria, but their effects on trans-translation were recently questioned. In this work, a series of new 1,3,4-oxadiazole derivatives and analogs were synthesized and assessed for their efficiency as antimicrobial agents against a wide range of gram-positive and gram-negative pathogenic strains. Despite the strong antimicrobial activity observed in these molecules, it turns out that they do not target trans-translation in vivo, but they definitely act on other cellular pathways.
