5840-10-8Relevant articles and documents
Organocatalyst-controlled site-selective arene C–H functionalization
Mao, Jian-Hui,Wang, Yong-Bin,Yang, Limin,Xiang, Shao-Hua,Wu, Quan-Hao,Cui, Yuan,Lu, Qian,Lv, Jie,Li, Shaoyu,Tan, Bin
, p. 982 - 991 (2021/08/12)
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.]
Light-sensitive, diazonium group-containing polycondensation product, process for its production, and light-sensitive recording material containing this polycondensation product
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, (2008/06/13)
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.