Flavones are important natural products with diverse biological activities. In this study, a novel procedure for the carbonylative synthesis of flavones has been developed by using simple phenols and internal alkynes as the substrates. Various flavones were isolated in moderate to good yields with excellent regioselectivity and functional group tolerance by using an iridium catalyst system. Notably
The Ru(II)-catalyzed C-H activation and annulation reaction of salicylaldehydes and disubstitutedalkynes affords chromones in high yields. This reaction works with terminal alkynes also and tolerates wide range of sensitive...
Microwave-accelerated, palladium-catalyzed carbonylative cyclization reactions of 2-iodophenol with alkynes Rapid and efficient synthesis of chromen-2-one derivatives
作者:Hong Cao、Wen-Jing Xiao
DOI:10.1139/v05-094
日期:2005.6.1
Rapid palladium-catalyzed carbonylative cyclization reactions of 2-iodophenol with various alkynes have been carried out by the use of commercially available molybdenumhexacarbonyl as a convenient and solid carbonmonoxidesource. The reactions were conducted at 160 °C for 30 min with microwave heating in the presence of DIEA and DMAP in 1,4-dioxane, and afford the corresponding chromen-2-one derivatives
Nickel-catalyzed C–O/O–H Annulation of Salicylate Esters with Alkynes: Activation of C–O Bond in Esters
作者:Yasuaki Iyori、Naoto Chatani
DOI:10.1246/cl.200885
日期:2021.3.5
The Ni-catalyzed C−O/O−H annulation of salicylate esters with alkynes, leading to the production of chromone derivatives is reported. The key step in the reaction is the cleavage of an acyl C-Obond. The presence of a base is essential for the reaction to proceed.
Oxidative [4 + 2] annulation of 1-naphthols with alkynes accelerated by an electron-deficient rhodium(<scp>iii</scp>) catalysts
作者:Antônio Junio Araujo Dias、Hiroto Takahashi、Juntaro Nogami、Yuki Nagashima、Ken Tanaka
DOI:10.1039/d1ob02181h
日期:——
The 1,3-diethoxycarbonyl-2,4,5-trimethylcyclopentadienyl (CpE) rhodium(III) complex displayed high efficacy in the catalytic oxidative annulation of 1-naphthols with internal alkynes under mild conditions. DFT calculations revealed that lower activation energies for the concerted metalation-deprotonation and the reductive elimination steps are the key to improved reactivity.
1,3-二乙氧基羰基-2,4,5-三甲基环戊二烯基(Cp E )铑( III )配合物在温和条件下对1-萘酚与内炔烃的催化氧化环化表现出高效。DFT 计算表明,协同金属化去质子化和还原消除步骤的较低活化能是提高反应性的关键。