Regioselective oxidative ring-opening of cyclopropenyl carboxylates by visible light photoredox catalysis
摘要:
Catalyzed by Ir(dFCF(3)ppy)(2)(dtbbpy)PF6, several aroyl methylidenemalonates were synthesized in good to excellent yields via visible light photoredox-catalyzed the oxidative ring-opening of cyclopropenyl carboxylate derivatives. The possible mechanism of oxidative quenching cycle was proposed. (C) 2018 Published by Elsevier Ltd.
Photooxygenation of differently functionalized furans is investigated in aqueous solutions and in ionic liquids [emim]Br and [bmim]BF4. The reaction is generally selective and the final products derive from rearrangement of the intermediate endoperoxides, depending mainly on the polarity and/or nucleophilic nature of the solvent.
Functionalized methyl cis-4-oxoalk-2-enoates 2 are synthesized in a one-pot procedure by singlet oxygen oxygenation of the corresponding 2-methoxyfurans 1 in methanol and reduction of the resulting hydroperoxides 4 and 5 by the sulfides 6 which are selectively oxidized into the sulfoxides 7. The synthetic method has a wide range of applicability and affords compounds 2 stereoselectively and in good yields; concomitantly the sulfoxides 7 are obtained in excellent yields.
DBU-catalyzed [3 + 2] cycloaddition and Michael addition reactions of 3-benzylidene succinimides with 3-ylidene oxindoles and chalcones
作者:Piyush Tehri、Rama Krishna Peddinti
DOI:10.1039/c9ob00385a
日期:——
A metal-free DBU catalyzed protocol has been developed for the regioselective [3 + 2] cycloaddition reactions of 3-benzylidene succinimides with 3-ylidene oxindoles to furnish spirooxindole derivatives. The 3-benzylidene succinimides underwent Michaeladdition with chalcones to provide benzylidene succinimide-tethered propanones. All the reactions proceeded under mild conditions and the products were