Transient and Recyclable Halogenation Coupling (TRHC) for Isoflavonoid Synthesis with Site‐Selective Arylation
作者:Jie‐Ping Wan、Zhi Tu、Yuyun Wang
DOI:10.1002/chem.201901025
日期:2019.5.17
designed for the synthesis of isoflavonoids through the domino reactions of o‐hydroxyphenyl enaminones and aryl boronic acids in the presence of catalytic KI and Pd catalyst. Instead of the conventional cross‐coupling strategy employing pre‐halogenated substrates, this method transforms raw C−H bond by means of a transient C−H halogenation to smoothly relay the subsequent C‐arylation. Consequently, such
Recyclable Palladium-Catalyzed Carbonylative Cyclization of Aryl Iodides and 2-Hydroxyacetophenones towards Flavones
作者:Mingzhong Cai、Bin Huang、Gang Xie、Jianan Zhan
DOI:10.1055/s-0042-1753042
日期:2023.2
A highly efficient heterogeneous palladium-catalyzedcarbonylative cyclization of aryl iodides and 2-hydroxyacetophenones is developed. The reaction proceeds efficiently in DMSO at 120 °C under 3 bar of carbon monoxide by using 2 mol% of an MCM-41-immobilized bidentate phosphine palladium complex [MCM-41-2P-Pd(OAc)2] as the catalyst and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as the base, providing
A concise and efficient method for the synthesis of 7-hydroxy-6H-naphtho[2,3-c]coumarin using available 1-(2-hydroxyphenyl)-2-phenylethanone and Meldrum's acid has been developed. This transformation involved a tandem aldol reaction/lactonization/Friedel–Crafts reaction to form a lactone ring and a benzene ring. It showed high atom economy with water and acetone as the byproducts. Mechanism studies
已经开发出使用可用的1-(2-羟基苯基)-2-苯基乙酮和Meldrum酸合成7-羟基-6 H-萘[2,3- c ]香豆素的简洁有效的方法。这种转化涉及串联的羟醛反应/内酯化/弗里德-克来福特反应,形成内酯环和苯环。以水和丙酮为副产物显示出高原子经济性。机理研究证明了Meldrum酸的两个作用:(i)作为串联反应的试剂,以及(ii)作为Friedel-Crafts反应的催化剂。此外,7-羟基-6 H-萘[2,3- c]香豆素进一步通过芳基乙炔基,芳基,和氰基基团,得到d-π-A的化合物具有优良的荧光发射(有效地官能化Φ ˚F = 0.14-0.78)。
Merchant, J. R.; Martyres, G., Journal of Heterocyclic Chemistry, 1980, vol. 17, # 9, p. 1331 - 1332