Palladium-Catalyzed Site-Selective Benzocylization of Aromatic Acids with <i>o</i>-Fluoro-Substituted Diaryliodonium Salts toward 3,4-Benzocoumarins
作者:Cheng Pan、Limin Wang、Jianwei Han
DOI:10.1021/acs.orglett.0c01577
日期:2020.6.19
By using 2-fluoro-substituted diaryliodoniumsalts, a novel benzocylization has been accomplished for the synthesis of 3,4-benzocoumarin derivatives via a cascade of ortho-arylation and defluorination in the presence of palladium catalysts. The reaction exhibits a broad compatibility of readily available aromatic acids with an excellent level of site-selectivity. Mechanistic investigations revealed
Copper catalyzed room temperature lactonization of aromatic C–H bond: a novel and efficient approach for the synthesis of dibenzopyranones
作者:Raju Singha、Shubhendu Dhara、Munmun Ghosh、Jayanta K. Ray
DOI:10.1039/c4ra13665a
日期:——
A novel and efficient methodology has been developed for the intramolecular aryl C–H oxidative lactonization of 2-arylbenzaldehyde using a low-cost CuCl catalyst and TBHP as the oxidant at room temperature.
Palladium-catalyzed one-pot Suzuki–Miyaura cross coupling followed by oxidative lactonization: a novel and efficient route for the one-pot synthesis of benzo[c]chromene-6-ones
作者:Raju Singha、Soumyabrata Roy、Sukla Nandi、Priyanka Ray、Jayanta K. Ray
DOI:10.1016/j.tetlet.2012.11.144
日期:2013.2
A number of 6H-benzo[c]chromene-6-ones, 5H-naphtho[1,2-c]chrome-5-ones, and 6H-naphtho[2,1-c]chromene-6-one have been synthesized starting with 2-hydroxyphenylboronic acid and o-bromobenzaldehyde or o-bromonaphthalene carboxaldehyde derivatives via a one-pot Suzuki-Miyaura cross coupling followed by oxidative lactonization reactions. The overall transformation consists of three reactions: Suzuki-Miyaura cross coupling, hemi-acetal formation, and oxidation. (c) 2012 Elsevier Ltd. All rights reserved.
Microwave-Assisted Cyclization under Mildly Basic Conditions: Synthesis of 6<i>H</i>-Benzo[<i>c</i>]chromen-6-ones and Their 7,8,9,10-Tetrahydro Analogues
作者:Pham Duy Quang Dao、Son Long Ho、Ho-Jin Lim、Chan Sik Cho
DOI:10.1021/acs.joc.8b00048
日期:2018.4.6
give the corresponding 6H-benzo[c]chromen-6-ones and their 7,8,9,10-tetrahydro analogues, respectively, in 50–72% yields. Aryl 3-bromoacrylates are also converted into 2H-chromen-2-ones under the employed conditions.
在K 2 CO 3的存在下,在二甲基甲酰胺中通过微波辐照,将2-溴苯甲酸芳酯和2-溴环己-1-芳烷基芳酯环化,得到相应的6 H-苯并[ c ] chromen-6-one及其7,8, 9,10-四氢类似物,产率分别为50-72%。在所采用的条件下,将3-溴丙烯酸芳基酯也转化为2 H-铬-2-基。