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Stereoselective electrosynthesis of the first individual (f,tA)‐ and (f,tC)‐1,4‐fullerene derivatives with a non‐inherently chiral functionalization pattern is described, as well as the first example of an optically pure protected primary amino acid directly linked to the fullerene through only the chiral α‐amino‐acid carbon atom. An application of an auxiliary chiral nickel‐Schiff base moiety as derivatizing agent allowed separation of (f,tA)‐ and (f,tC)‐1,4‐fullerene derivatives using an achiral stationary phase, a separation which has never been done before.  相似文献   

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It is well established, that nutrition plays a basic role in the prevention of typically chronic western diseases like cancer and atherosclerosis. So, the tendency of the nutrition science is to optimize nutrition. A modern concept of this idea is the design of functional foods. Widely used ingredients of functional foods are ω‐3 fatty acids, in particular the long chain fatty acids eicosapentaenic acid (EPA) and docosahexaenoic acid (DHA). Dietary ω‐3 fatty acids have effects on various physiological processes such as the fluidity of cell membranes, modulation of ion channels and the immune system. These effects are the basis of dietary supplementation with ω‐3 fatty acids in several diseases, like atherosclerosis. The usual German consumption habits lead to a deficiency of about 1 g EPA and DHA. Micro‐encapsulated oils with a high content of ω‐3 fatty acids added to functional foods could optimize the supply.  相似文献   

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The formation of well‐defined finite‐sized aggregates represents an attractive goal in supramolecular chemistry. In particular, construction of discrete π‐stacked dye assemblies remains a challenge. Reported here is the design and synthesis of a novel type of discrete π‐stacked aggregate from two comparable perylenediimide (PDI) dyads ( PEP and PBP ). The criss‐cross PEP ‐ PBP dimers in solution and ( PBP ‐ PEP )‐( PEP ‐ PBP ) tetramers in the solid state are well elucidated using single‐crystal X‐ray diffraction, dynamic light scattering, and diffusion‐ordered NMR spectroscopy. Extensive π–π stacking between the PDI units of PEP and PBP as well as repulsive interactions of swallow‐tailed alkyl substituents are responsible for the selective formation of discrete dimer and tetramer stacks. Our results reveal a new approach to preparing discrete π stacks that are appealing for making assemblies with well‐defined optoelectronic properties.  相似文献   

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The conversion of saturated fatty acids to high value chiral hydroxy‐acids and lactones poses a number of synthetic challenges: the activation of unreactive C?H bonds and the need for regio‐ and stereoselectivity. Here the first example of a wild‐type cytochrome P450 monooxygenase (CYP116B46 from Tepidiphilus thermophilus) capable of enantio‐ and regioselective C5 hydroxylation of decanoic acid 1 to (S)‐5‐hydroxydecanoic acid 2 is reported. Subsequent lactonization yields (S)‐δ‐decalactone 3 , a high value fragrance compound, with greater than 90 % ee. Docking studies provide a rationale for the high regio‐ and enantioselectivity of the reaction.  相似文献   

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