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101.
Mpeyake Jacob Maseme Dr. Alizé Pennec Dr. Jacqueline van Marwijk Prof. Diederik Johannes Opperman Martha Sophia Smit 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(26):10445-10448
The self-sufficient cytochrome P450 monooxygenase CYP505E3 from Aspergillus terreus catalyzes the regioselective in-chain hydroxylation of alkanes, fatty alcohols, and fatty acids at the ω-7 position. It is the first reported P450 to give regioselective in-chain ω-7 hydroxylation of C10–C16 n-alkanes, thereby enabling the one step biocatalytic synthesis of rare alcohols such as 5-dodecanol and 7-tetradecanol. It shows more than 70 % regioselectivity for the eighth carbon from one methyl terminus, and displays remarkably high activity towards decane (TTN≈8000) and dodecane (TTN≈2000). CYP505E3 can be used to synthesize the high-value flavour compound δ-dodecalactone via two routes: 1) conversion of dodecanoic acid into 5-hydroxydodecanoic acid (24 % regioselectivity), which at low pH lactonises to δ-dodecalactone, and 2) conversion of 1-dodecanol into 1,5-dodecanediol (55 % regioselectivity), which can be converted into δ-dodecalactone by horse liver alcohol dehydrogenase. 相似文献
102.
Photocatalytic approaches for the production of solar hydrogen or hydrocarbons are interesting as they provide a sustainable alternative to fossil fuels. Research has been focused on water splitting and on the synthesis of photocatalyst materials and compounds, and their characterization. The material-related challenges include the synthesis and design of photocatalysts that can absorb visible light at a high quantum efficiency, cocatalysts that are selective and can accelerate the reduction and/or oxidation reactions, and protection layers that facilitate migration of the minority carriers to the surface-active sites while reducing charge recombination and photo-corrosion. Less attention has been paid to the conceptual design of reactors, and how design and coupled transport can affect the material choice and requirements. This perspective discusses the various possible conceptual designs for particle suspension reactors and the related implications on the material requirements to achieve high energy conversion efficiencies. We establish a link between the thermodynamic limits, materials requirements, and conceptual reactor designs, quantify changes in material requirements when more realistic operation and losses are considered, and compare the theory-derived guidelines with the ongoing materials research activity.This perspective discusses the various possible conceptual designs for particle suspension reactors and the related implications on the material and reactor requirements to achieve high STH conversion efficiencies. 相似文献
103.
Quinine, nicotine, and related electron-rich amino-substituted pyridines were readily metalated using LiCl-solubilized TMP (2,2,6,6-tetramethylpiperidyl) bases in the presence of BF(3)·OEt(2). A full pyridine functionalization of all five positions of the pyridine ring can be realized by using an appropriate combination of TMP bases in the presence or absence of BF(3)·OEt(2). 相似文献
104.
A scalable synthesis of the "flat" tridecameric inorganic cluster [Al(13)(μ(3)-OH)(6)(μ-OH)(18)(H(2)O)(24)](15+) has been realized by treating an aqueous aluminum nitrate solution with a zinc-metal powder at room temperature. Single crystals and polycrystalline samples are readily obtained in yields exceeding 55% relative to the starting reagent Al(NO(3))(3). Products have been characterized by X-ray diffraction and solid-state (27)Al MAS and MQMAS NMR. 相似文献
105.
Benndorf P Schmitt S Köppe R Oña-Burgos P Scheurer A Meyer K Roesky PW 《Angewandte Chemie (International ed. in English)》2012,51(20):5006-5010
Easy come, easy go: the first molecular SO(2) complexes of the lanthanides (Ln=Sm, Eu) have been prepared. The compounds can reversibly coordinate gaseous SO(2). Concomitant with the addition and removal of SO(2), the color of the complexes changes reversibly. The structures of the SO(2) compounds could be confirmed in solution and in the solid state. 相似文献
106.
Sophia Kalpazidou 《随机分析与应用》2013,31(4):481-492
Equations generating directed cycles in at most countable sets are considered. Such equations are the balance relations for recurrent continuous parameter Markov processes that in term of algebraic topology generate the 1-cycles. Connections of cycle generating equations with the recurrent behavior of Markov processes are given 相似文献
107.
Sophia?DemouliniEmail author David?M.?A.?Stuart Athanasios?E.?Tzavaras 《Archive for Rational Mechanics and Analysis》2012,205(3):927-961
For the equations of elastodynamics with polyconvex stored energy, and some related simpler systems, we define a notion of a dissipative measure-valued solution and show that such a solution agrees with a classical solution with the same initial data, when such a classical solution exists. As an application of the method we give a short proof of strong convergence in the continuum limit of a lattice approximation of one dimensional elastodynamics in the presence of a classical solution. Also, for a system of conservation laws endowed with a positive and convex entropy, we show that dissipative measure-valued solutions attain their initial data in a strong sense after time averaging. 相似文献
108.
Solutions of [(C6H5)3P]3CoCH3 (I) in C6H5Cl yield biphenyl, triphenylphosphine, methyldiphenylphosphine and diphenylphosphine. In 4-ClC6H4CH3, 4-methylbiphenyl and 4,4′-bitolyl form as well. Solutions of I in C6H6, C6D6, C6H5CH3, C6H5Br yield only triphenylphosphine and biphenyl, while in 4-FC6H4I 4,4′-difluorobiphenyl is formed but no biphenyl. The cobalt compound is recovered as (Ph3P)nCoX or as CoX2 (XCl, Br, I, n = 3 or 2) from reactions with arylhalides. The results are rationalized in terms of the very strong tendency for I to undergo oxidative addition reactions. 相似文献
109.
In this paper we examine semilinear hemivariational inequalities at resonance at any eigenvalue of the negative Laplacian with Dirichlet boundary condition. Our approach is variational based on the Nonsmooth Critical Point Theory and it uses a generalized Landesman–Lazer condition. We prove two existence theorems using two different forms of the generalized Landesman–Lazer condition. In the last section we show that our Landesman-Lazer condition is more general than the ones existing in the literature. 相似文献
110.
Sophia Mitkidou Julia Stephanidou-Stephanatou Helen Stephopoulou 《Journal of heterocyclic chemistry》1993,30(2):441-444
Aroylhydrazines 2 reacted with 3-benzylidene-2,4-pentanedione ( 1 ) to give 1-aroyl-3,5-dimethyl-1H-pyrazoles 5 and benzaldehyde aroylhydrazones 6 . From the reaction of 3-methoxymethylene-2,4-pentanedione ( 7 ) with aroylhydrazines 2 the unknown N-aroyl-4-acetyl-1H-pyrazoles 9 were exclusively isolated in good yields. 相似文献