Iron-Catalyzed Synthesis of Functionalized 2H-Chromenes via Intramolecular Alkyne−Carbonyl Metathesis
摘要:
An iron-catalyzed intramolecular alkyne-aldehyde metathesis strategy of the alkynyl ether of salicylaldehyde derivatives has been developed which works under mild reaction conditions to produce the functionalized 2H-chromene derivatives. This protocol is compatible toward a wide range of functional groups, such as methoxy, fluoro, chloro, brow, and phenyl groups. This method provides an atom-economical and environmentally friendly approach for the synthesis of a series of substituted 2H-chromenes.
Pyridinium triflate catalyzed intramolecular alkyne-carbonyl metathesis reaction of O-propargylated 2-hydroxyarylaldehydes
作者:Manoj Kumar Saini、Harshita Singh Korawat、Shashi Kant Verma、Ashok K. Basak
DOI:10.1016/j.tetlet.2020.152657
日期:2020.12
3,5-Dibromopridinium trifluoromethanesulfonate catalyzes the intramolecular alkyne-carbonyl metathesis reaction of a variety of O-propargylated 2-hydroxyarylaldehydes and ketonesbearingalkyl, aryl and heteroaryl substituted internal alkynes to provide various 3-(hetero)aroyl 2H-chromenes in high yields.
A convenient general synthesis of 3-substituted 2H-chromene derivatives
作者:Perry T Kaye、Xolani W. Nocanda
DOI:10.1039/b201827f
日期:2002.5.10
Reactions of 2-hydroxybenzaldehydes and 2-hydroxy-1-naphthaldehydes with various activated alkenes under Baylis–Hillman conditions have been shown to proceed with regioselective cyclisation to afford the corresponding 3-substituted chromene derivatives. In some cases competitive dimerisation of the alkene component was observed, and direct dimerisation in the absence of the aldehyde has been explored.
Barluenga's reagent with HBF<sub>4</sub>as an efficient catalyst for alkyne-carbonyl metathesis of unactivated alkynes
作者:Kosuke Murai、Keiichiro Tateishi、Akio Saito
DOI:10.1039/c6ob02090a
日期:——
Barluenga's reagent (IPy2BF4, Py = pyridine) treated with HBF4 efficiently catalyzes the inter- and intramolecular alkyne-carbonyl metathesis of unactivated alkynes with aldehydes or ketones, most of which proceed at room temperature. This work represents the first catalytic application of the Barluenga's reagent.
Synthèse de benzopyrannopyridines et de dihydrobenzoquinoléines
作者:Marie-Claude Bellassoued-Fargeau、Pierre Maitte
DOI:10.1002/jhet.5570210561
日期:1984.9
La cycloaddition thermique d'un système α-énone avec l'oxyde de vinyle et d'éthyle conduit à un éthoxy-2 dihydropyranne aisément transformé en pyridine par action du chlorhydrate d'hydroxylamine. Ce schéma réactionnel a permis de réaliser la synthèsede benzopyrannopyridines et de dihydrobenzoquinoléines.
Chalcones can exist as Z- or E-isomers and it is generally anticipated that both isomers are equipotent. In order to determine the active isomer of anti-plasmodial chalcones a series of analogues locked in the Z- or the E-form were prepared and evaluated for their anti-plasmodial activity. It was shown that the Z-locked analogue was nearly inactive, whereas the E-locked analogues were equipotent to the parent chalcones, indicating that the E-isomer is the active conformation. (c) 2005 Elsevier Ltd. All rights reserved.