- Organocatalyst-controlled site-selective arene C–H functionalization
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Over the past three decades, organocatalysis has emerged as a powerful catalysis platform and has gradually been incorporated into the routine synthetic toolbox to obtain chiral molecules. However, its application in the site- and enantioselective functionalization of inactive aryl C–H bonds remains in its infancy. Here, we present an organocatalyst-controlled para-selective arene C–H functionalization strategy that addresses this issue, which remains an enduring challenge in arene functionalization chemistry. By emulating enzyme catalysis, the chiral phosphoric acid catalyst offers an ideal chiral environment for stereoinduction, and the projecting substituents give control of chemo- and site-selectivity. Various types of nucleophile are compatible with this method, affording more than 100 para-selective adducts with stereodefined carbon centres or axes in viable molecular contexts. This protocol is expected to provide a general strategy for para-selective functionalization of arene C–H bonds in a controlled manner. [Figure not available: see fulltext.]
- Mao, Jian-Hui,Wang, Yong-Bin,Yang, Limin,Xiang, Shao-Hua,Wu, Quan-Hao,Cui, Yuan,Lu, Qian,Lv, Jie,Li, Shaoyu,Tan, Bin
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p. 982 - 991
(2021/08/12)
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- Novel PPARδ antagonist and Pharmaceutical composition for enhancing anti-cancer effect comprising the same
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The present invention relates to a novel PPARΔ antagonist compound, and uses thereof for inhibiting liver cancer resistance to sorafenib and enhancing anticancer effects, wherein the compound of the present invention can be usefully used as a pharmaceutical composition for treating sorafenib-resistant progressive liver cancer.
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- Light-sensitive, diazonium group-containing polycondensation product, process for its production, and light-sensitive recording material containing this polycondensation product
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A light-sensitive, diazonium group-containing polycondensation product is described which comprises (a) an optionally substituted diphenylamine-dianzonium salt I. (b) a compound corresponding to the formula II wherein R4 is H, alkyl or acyl, and R5 is an optionally substituted aromatic radical, and (c) a compound corresponding to the formula III wherein R6 and R7 are H, alkyl, or acyl and R8 is the radical of a compound selected from the group consisting of aromatic hydrocarbons, phenols, phenolethers, aromatic thioethers, aromatic heterocyclic compounds, and organic acid amides, with the radicals resulting from compound II being directing linked to the units of the diazonium salt I. In the production of the polycondensation product, I is first condensed with II and then with III. The product is suitable for use as a light-sensitive substance in recording materials, particularly in printing plates, and yields light-hardening products which have an increased oleophilicity.
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- Light-sensitive polycondensation product containing diazonium and dialdehyde groups, and light-sensitive recording material prepared therewith
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A light-sensitive diazonium group-containing polycondensation product of a diazonium salt corresponding to the general formula STR1 wherein R1, R2, and R3 denote hydrogen atoms, halogen atoms, alkyl groups having 1 to 3 carbon atoms or alkoxy groups having 1 to 6 carbon atoms, and X denotes the anion of the diazonium salt, and an aldehyde selected from the group consisting of dialdehydes, acetals of dialdehyde hydrates, and esters of dialdehyde hydrates, a process for producing such a light-sensitive polycondensation product and a light-sensitive recording material comprising a layer support and a light-sensitive layer containing such a light-sensitive polycondensation product.
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