- Biomimetic carbene cascades enabled imine derivative migration from carbene -bearing thiocarbamates
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Inspired by the body circulation of Omeprazole (irreversible proton pump inhibitor), we disclose the carbene-triggered cascades for the synthesis of 2-aminobenzofuran derivatives from N-sulfonyl-1,2,3-triazoles or benzothioazole-bearing thiocarbamates, which represents an unprecedented imine derivative migration process. Furthermore, the desulfurizing reagent-free Barton-Kellogg-type reactions starting from N-sulfonyl-1,2,3-triazoles have also been achieved for the first time, and elemental sulfur is confirmed as a byproduct during this transformation. Both experimental data and DFT calculations further thoroughly explained the unique reactivity.
- Li, Xue,Chen, Haohua,Xuan, Qingqing,Mai, Shaoyu,Lan, Yu,Song, Qiuling
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supporting information
p. 3518 - 3523
(2021/05/29)
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- Photocatalytic Biheterocyclization of 1,7-Diynes for Accessing Skeletally Diverse Tricyclic 2-Pyranones
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A new and green route to skeletally diverse oxo-heterocyclic architectures such as pyrano[3,4-c]chromen-2-ones and pyrano[3,4-c]quinolin-2-ones is reported via an unprecedented photocatalytic Kharasch-type cyclization/1,5-(SN″)-substitution/elimination/6π
- Wang, Lu,Xu, Ting,Rao, Qian,Zhang, Tian-Shu,Hao, Wen-Juan,Tu, Shu-Jiang,Jiang, Bo
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supporting information
p. 7845 - 7850
(2021/10/20)
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- Oxyacylation of Iodoalkynes: Gold(I)-Catalyzed Expeditious Access to Benzofurans
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(Acetonitrile)[1,3-bis(2,6-diisopropylphenyl)-imidazole-2-ylidene] gold(I) catalyzes the cycloisomerization of 2-(iodoethynyl)aryl esters to give 3-iodo-2-acyl benzofurans. This catalytic transformation is the result of an unprecedented selective syntheti
- Fernández-Canelas, Paula,Rubio, Eduardo,González, José M.
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supporting information
p. 6566 - 6569
(2019/08/20)
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- Palladium-catalyzed reaction of o-ethynylphenols, o-((trimethylsilyl)ethynyl)phenyl acetates, and o-alkynylphenols with unsaturated triflates or halides: A route to 2-substituted-, 2,3-disubstituted-, and 2-substituted-3-acylbenzo[b]furans
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The reaction of o-ethynylphenols 3 with a wide variety of unsaturated halides or triflates 6 in the presence of Pd(OAc)2(PPh3)2, CuI, and Et3N (procedure A) gives 2-vinyl- and 2-arylbenzo[b]furans 7, in good to high yield, through a palladium-catalyzed coupling followed by an in situ cyclization step. Small amounts of 2,3-disubstituted-benzo[b]furans 8 are usually isolated as side products. In some cases, however, compounds 8 are generated in significant yield or even as the main products. The formation of 8 can be prevented by employing alternative procedures (B and C) that use o-((trimethylsilyl)ethynyl)phenyl acetates 5 as starting building blocks. Procedure B is based on the palladium-catalyzed reaction of 5 with 6 in the presence of Pd(PPh3)4, Et3N, and n-Bu4NF, followed by the hydrolysis of the resultant coupling derivative 12 under basic conditions. Procedure C affords 7 through an in situ coupling cyclization of 5 with 6 in the presence of Pd(PPh3)4 and KOBu(t). The utilization of o-alkynylphenols 9 as the starting alkynes in the palladium-catalyzed reaction with 6 leads to the formation of 2,3-disubstituted-benzo[b]furans 13 through an annulation process promoted by σ-vinyl- and σ-arylpalladium complexes generated in situ. The best results in this case are obtained by using KOAc and Pd(PPh3)4. In the presence of KOAc and Pd(PPh3)4, and under an atmosphere of carbon monoxide, the reaction of o-alkynylphenols with 6 provides 2-vinyl- and 2-aryl-3-acylbenzo[b]furans 14.
- Arcadi,Cacchi,Del Rosario,Fabrizi,Marinelli
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p. 9280 - 9288
(2007/10/03)
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