41255-31-6Relevant academic research and scientific papers
Rh-Catalyzed aldehydic C-H alkynylation and annulation
Ramakrishna, Boddu S.,Rao, Maddali L. N.
, p. 1402 - 1411 (2020/03/03)
Novel Rh-catalyzed aldehydic C-H bond alkynylation and annulation for the in situ synthesis of chromones and aurones are described. It involves the sequential aldehyde C-H bond alkynylation of salicylaldehyde with in situ generated 1-bromoalkyne from 1,1-
Novel and Efficient Access to Flavones under Mild Conditions: Aqueous HI-Mediated Cascade Cyclization/Oxidative Radical Reaction of 2-Propynolphenols
Song, Xian-Rong,Li, Ren,Yang, Tao,Chen, Xi,Ding, Haixin,Xiao, Qiang,Liang, Yong-Min
supporting information, p. 5548 - 5552 (2018/10/24)
Herein we disclose a metal-free and efficient method for the direct conversion of 2-propynolphenols to biologically important flavones using aqueous HI as the promoter. This transformation was proved via 4-iodo-2H-chromenes intermediate, which was simultaneously conversed to corresponding flavones by a Csp2?I bond cleavage and a C–O bond formation under air.
An efficient oxidative conversion of 2-aryl-2H-chromenes to the corresponding flavones by tert-butylhydroperoxide and copper bromide
Banerjee, Dipanwita,Kayal, Utpal,Maiti, Gourhari
supporting information, p. 1667 - 1671 (2016/04/04)
A simple and efficient method has been developed for the facile oxidation of chromenes to the corresponding flavones by tert-butylhydroperoxide (TBHP) in the presence of copper(II) bromide catalyst in toluene at 80 °C in a very short time. The reaction demonstrates excellent reactivity, functional group tolerance, and good to excellent yields without using conventional strong oxidizing agents.
Pd(OAc)2/S=PPh3 accelerated activation of gem-dichloroalkenes for the construction of 3-arylchromones
Liu, Jianming,Song, Weiwei,Yue, Yuanyuan,Liu, Ren,Yi, Hong,Zhuo, Kelei,Lei, Aiwen
supporting information, p. 17576 - 17579 (2015/12/08)
The Pd-catalyzed regioselective intramolecular nucleophilic substitution of gem-dichloroalkene derivatives with salicylaldehydes leading to the synthesis of 3-arylchromones has been developed. Pd(OAc)2/S=PPh3 could activate gem-dichloroalkenes and undergo nucleophilic substitution by salicylaldehydes with the aid of a base.
K2CO3-catalyzed synthesis of chromones and 4-quinolones through the cleavage of aromatic C-O bonds
Zhao, Jie,Zhao, Yufen,Fu, Hua
supporting information; experimental part, p. 2710 - 2713 (2012/07/16)
Phenol-derived electrophiles are favorable substrates because phenols are naturally abundant or can be readily prepared from other aromatic compounds. However, the cleavage of aromatic C-O bonds is a great challenge because of their high energy. K2CO3-catalyzed intramolecular cyclization of 1-(2-alkoxyphenyl)-3-akylpropane-1,3-dione and 3-(alkylimino)-1-(2-methoxyphenyl)-2-methylpropan-1-one derivatives via the selective cleavage of aromatic C-O bonds is reported. The corresponding chromone and 4-quinolone derivatives were obtained in reasonable yields.
Transition-metal-free intramolecular Ullmann-type O-arylation: Synthesis of chromone derivatives
Zhao, Jie,Zhao, Yufen,Fu, Hua
supporting information; experimental part, p. 3769 - 3773 (2011/05/15)
(Chemical Equation Presented) Expect the upexpected: A transition-metal- free approach to access chromone derivatives has been developed. The intramolecular O-arylation of substituted 1-(2-haloaryl)-propane-1,3-diones in DMF in the presence of K2CO3 gave the corresponding target products in good to excellent yields (see scheme; DMF = N,N′- dimethylformamide).
A facile synthesis of flavones catalysed by gallium(III) triflate
Jin, Can,He, Fei,Wu, Huayue,Chen, Jiuxi,Su, Weike
experimental part, p. 27 - 29 (2009/09/25)
Ga(OTf)3 was explored as a novel catalyst for the cyclisation of 1-(2-hydroxyphenyl)-3-aryl-1,3-propanediones in nitromethane to flavones with excellent yields.
Mechanically activated solid-state synthesis of flavones by high-speed ball milling
Zhu, Xingyi,Li, Zhenhua,Shu, Qiangfeng,Zhou, Chenfeng,Su, Weike
experimental part, p. 4199 - 4211 (2010/01/16)
An efficient, mechanically activated solid-state synthesis of flavones from 1-(2-hydroxyphenyl)-3-aryl-1,3-propanediones using high-speed ball milling is described. This method has notable advantages in terms of good yield, short reaction time, and neat conditions.
