Pyridinium Chloride: a New Reagent for N-Demethylation of N-Methylazinium Derivatives.
摘要:
A new N-demethylation reaction of N-methylazinium derivatives by using boiling pyridinium chloride is described. The reaction is quite clean, fast and yields are almost quantitatives. (C) 1997 Elsevier Science Ltd.
A series of unsaturated carbonyls, quinones, and pyridinium salts have been effectively reduced to the corresponding saturated carbonyls, dihydroxybenzenes, and hydropyridines in moderate to high yields with tetrahydroxydiboron/water as a mild, convenient, and metal-free reduction system. Deuterium-labeling experiments have revealed this protocol to be an exclusive transfer hydrogenation process from
Copper-Catalyzed (4+1) Cascade Annulation of Terminal Alkynes with 2-(Tosylmethyl)anilines: Synthesis of 2,3-Disubstituted Indoles
作者:Xu Yan、Chun-Fang Liu、Xian-Tao An、Xiao-Min Ge、Qing Zhang、Lin-Han Pang、Xu Bao、Chun-An Fan
DOI:10.1021/acs.orglett.1c03402
日期:2021.11.19
alkynes as one-carbon synthons with 2-(tosylmethyl)anilines has been developed for the expeditious synthesis of 2,3-disubstituted indoles, in which in situ generations of aza-o-quinone methides and alkynyl-copper(I) species are involved. This annulation provides an effective method for the assembly of synthetically and structurally interesting 2,3-disubstituted indoles.
已经开发了一种基于 Cu 催化 (4+1) 级联环化末端炔作为单碳合成子与 2-(甲苯磺酰甲基)苯胺的新策略,用于快速合成 2,3-二取代吲哚,其中原位生成的氮杂Ó -quinone甲基化物和炔基-铜(I)类的参与。这种环化为合成和结构上有趣的 2,3-二取代吲哚的组装提供了一种有效的方法。
Deprotonated Salicylaldehyde as Visible Light Photocatalyst
作者:Yan-Jun Zhuang、Jian-Ping Qu、Yan-Biao Kang
DOI:10.1021/acs.joc.0c00102
日期:2020.3.20
by the deprotonated salicylaldehyde through an energy-transfer pathway. Consequently, the C-C cleaving alkylation reactions of N-hydroxyphthalimide esters proceed smoothly in the presence of as low as 1 mol % of salicylaldehyde under the visible-light irradiation, affording desired alkylation products with up to 99% yields. Application in visible-light induced aerobic oxidation of N-alkylpyridinium
contacts with quinoid rings have been described in novel co-crystals of tetrabromo- and tetrachloroquinone with iodide salts of substituted N-methylpyridinium cations. In seven crystalstructures of these co-crystals, a centrosymmetric unit I–···quinone···I– is observed involving close contacts between iodide anions and electron-depleted carbon skeletons of the quinoid rings. However, the salt with
transformation. This reaction features ambient air as the sole oxidant and oxygen source, a broad substrate scope, and excellent functional-group tolerance and proceeds under mild reaction conditions. Furthermore, a highly efficient synthesis of bioactive molecules and natural products including N-methylcrinasiadine, N-isopentylcrinasiadine, N-phenethylcrinasiadine, isoindolo[2,1-b]isoquinolin-5(7H)-one, PJ-34,