Successively Recycle Waste as Catalyst: A One-Pot Wittig/1,4-Reduction/Paal–Knorr Sequence for Modular Synthesis of Substituted Furans
摘要:
A one-pot tandem Wittig/conjugate reduction/PaalKnorr reaction is reported for the synthesis of di- or trisubstituted furans. This novel sequence first demonstrates the possibility of successively recycling waste from upstream steps to catalyze downstream reactions.
A new domino reaction has been developed that allows the combination of styrenes and α‐alkyl ketone radicals to afford a wide array of polysubstituted furans in good to excellent yields under mild and simple reaction conditions. The key to success of this novel protocol is the use of photocatalyst fac‐Ir(ppy)3 and oxidant K2S2O8. Mechanistic studies by a radical scavenger and photoluminescence quenching
已开发出一种新的多米诺反应,该反应允许苯乙烯和α-烷基酮自由基的组合在温和简单的反应条件下以良好或优异的收率提供各种各样的多取代呋喃。该新协议成功的关键是使用光催化剂fac ‐Ir(ppy)3和氧化剂K 2 S 2 O 8。通过自由基清除剂和光致发光猝灭的机理研究表明,自由基加成/氧化途径是可行的。
A co-operative effect of visible light photo-catalysis and CoFe<sub>2</sub>O<sub>4</sub> nanoparticles for green synthesis of furans in water
作者:Fooleswar Verma、Puneet K. Singh、Smita R. Bhardiya、Manorama Singh、Ankita Rai、Vijai K. Rai
DOI:10.1039/c6nj04091h
日期:——
A novel approach to poly-functionalized furansynthesis is disclosed via oxidative decarboxylative [3+2] cycloaddition using co-operative catalysis by visible light and CoFe2O4 nanoparticles under ambient reaction conditions with water as a solvent. Although the reported method is efficient without catalyst in the presence of visible light (70% yield in 4 h at rt), the use of catalyst not only increases
在环境反应条件下,以水为溶剂,通过可见光和CoFe 2 O 4纳米粒子的协同催化,通过氧化脱羧[3 + 2]环加成反应,公开了一种多官能化呋喃合成的新方法。尽管所报道的方法在可见光存在下不使用催化剂也是有效的(在室温4小时内产率为70%),但使用催化剂不仅可以提高产率(91%),而且可以加快转化率(在室温2小时) 。
Copper-catalyzed regioselective synthesis of furan via tandem cycloaddition of ketone with an unsaturated carboxylic acid under air
A catalytic decarboxylative annulation has been developed for the regioselective synthesis of trisubstituted furans by the cycloaddition of ketones with α,β-unsaturated carboxylic acids under ambient air. A library of furan derivatives were obtained in good yields from the readily available substrates in the combination of a catalytic amount of Cu-salt and a stoichiometric amount of water. Water plays
A regioselectivesynthesis of multisubstituted furan derivatives has been developed via Cu(II)-catalyzed intermolecular annulation of aryl ketones with a wide range of aromatic olefins under ambient air in good yields. This protocol is applicable to both cyclic and acyclic aryl ketones.