7404-47-9Relevant academic research and scientific papers
Anin situmasking strategy enables radical monodecarboxylative C-C bond coupling of malonic acid derivatives
Chen, Jia-Zheng,Chen, Jian-Ping,Cheng, He-Li,Wang, Zhen,Xie, Xian-Hui
, p. 11786 - 11792 (2021/09/22)
The utilization of malonic acids in radical decarboxylative functionalization is still underexploited, and the few existing examples are primarily limited to bisdecarboxylative functionalization. While radical monodecarboxylative functionalization is highly desirable, it is challenging because of the difficulty in suppressing the second radical decarboxylation step. Herein, we report the successful radical monodecarboxylative C-C bond coupling of malonic acids with ethynylbenziodoxolone (EBX) reagents enabled by anin situmasking strategy, affording synthetically useful 2(3H)-furanones in satisfactory yields. The keys to the success of this transformation include (1) the dual role of a silver catalyst as a single-electron transfer catalyst to drive the radical decarboxylative alkynylation and as a Lewis acid catalyst to promote the 5-endo-digcyclization and (2) the dual function of the alkynyl reagent as a radical trapper and as anin situmasking group. Notably, the latent carboxylate group in the furanones could be readily released, which could serve as a versatile synthetic handle for further elaborations. Thus, both carboxylic acid groups in malonic acid derivatives have been well utilized for the rapid construction of molecular complexity.
Photochemical and Thermal Transformations of 3-Benzyl-2(3H)-furanones and Related Substrates
Gopidas, K. R.,Cyr, D. R.,Das, P. K.,George, M. V.
, p. 5505 - 5511 (2007/10/02)
Photochemical and thermal transformations of several 2(3H)-furanones are reported.Steady-state irradiations of 3-benzyl-3,5-diphenyl-2(3H)-furanone (1a) in benzene or methanol, for example, gave a mixture of 2,3,5-triphenylfuran (3a) (8-9percent) and 1,3,5-triphenylbut-3-en-1-one (6a) (26-34percent), along with 34-37percent recovery of the unchanged starting material.Similar results were obtained with 3-benzyl-3-(4-methylphenyl)-5-phenyl-2-(3H)-furanone (1b) and 3-benzyl-3-(4-methoxyphenyl)-5-phenyl-2(3H)-furanone (1c) under analogous conditions.Upon direct irradiation, 3,3-dibenzyl-5-phenyl-2(3H)-furanone (1d), however, gave only 3-benzyl-1,4-diphenylbut-3-en-1-one (6d) (80-83percent), whereas 3-benzyl-3-phenylphenanthrofuran-2(3H)-one (1e) gave only 2,3-diphenylphenanthrofuran (3e) (15-21percent).On the other hand, 3-benzoyl-3,5-diphenyl-2(3H)-furanone (1f) gave only the bis lactone 10a (72-75percent) under direct photolysis.The bis lactones 10a-c and the rearranged 5-benzyl-3,5-diaryl-2(5H)-furanones 9a-d were the major products in the course of sensitized irradiation of 1a-d in the presence of acetophenone in benzene.The thermolysis of 1a-d also led to the formation of the rearrangement products 9a-d in high yields (60-80percent).Possible mechanisms of these various photochemical and thermal reactions are discussed in terms of singlet-mediated decarbonylation, triplet-sensitized homolysis of the benzyl-to-furanone bond and probable thermal -sigmatropic shift of the benzyl group.The laser pulse photoexcitation (337.1 nm) of benzophenone in the presence of 1a-d in benzene of acetonitrile produces the short-lived triplets of the 2(3H)-furanones (τT = 0.5-3.0 μs), which subsequently undergo bond cleavage lea ding to furanoxy radicals.The spectral and kinetic features of the triplets and the radicals are presented.
