- Catalyst-Free Decarbonylative Trifluoromethylthiolation Enabled by Electron Donor-Acceptor Complex Photoactivation
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A catalyst- and additive-free decarbonylative trifluoromethylthiolation of aldehyde feedstocks has been developed. This operationally simple, scalable, and open-to-air transformation is driven by the selective photoexcitation of electron donor-acceptor (EDA) complexes, stemming from the association of 1,4-dihydropyridines (donor) with N-(trifluoromethylthio)phthalimide (acceptor), to trigger intermolecular single-electron transfer events under ambient- and visible light-promoted conditions. Extension to other electron acceptors enables the synthesis of thiocyanates and thioesters, as well as the difunctionalization of [1.1.1]propellane. The mechanistic intricacies of this photochemical paradigm are elucidated through a combination of experimental efforts and high-level quantum mechanical calculations [dispersion-corrected (U)DFT, DLPNO-CCSD(T), and TD-DFT]. This comprehensive study highlights the necessity for EDA complexation for efficient alkyl radical generation. Computation of subsequent ground state pathways reveals that SH2 addition of the alkyl radical to the intermediate radical EDA complex is extremely exergonic and results in a charge transfer event from the dihydropyridine donor to the N-(trifluoromethylthio)phthalimide acceptor of the EDA complex. Experimental and computational results further suggest that product formation also occurs via SH2 reaction of alkyl radicals with 1,2-bis(trifluoromethyl)disulfane, generated in-situ through combination of thiyl radicals. (Figure presented.).
- Lipp, Alexander,Badir, Shorouk O.,Dykstra, Ryan,Gutierrez, Osvaldo,Molander, Gary A.
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supporting information
p. 3507 - 3520
(2021/06/11)
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- Rh(I)-Catalyzed Intramolecular Decarbonylation of Thioesters
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Decarbonylative synthesis of thioethers from thioesters proceeds in the presence of a catalytic amount of [Rh(cod)Cl]2 (2 mol %). The protocol represents the first Rh-catalyzed decarbonylative thioetherification of thioesters to yield valuable thioethers. Notable features include the absence of phosphine ligands, inorganic bases, and other additives and excellent group tolerance to aryl chlorides and bromides that are problematic using other metals to promote decarbonylation. Gram scale synthesis, late-stage pharmaceutical derivatization, and orthogonal site-selective cross-couplings by C-S/C-Br cleavage are reported.
- Cao, Han,Liu, Xuejing,Bie, Fusheng,Shi, Yijun,Han, Ying,Yan, Peng,Szostak, Michal,Liu, Chengwei
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p. 10829 - 10837
(2021/07/28)
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- Controlled Ni-catalyzed mono- and double-decarbonylations of α-ketothioesters
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A method for Ni-catalyzed controlled decarbonylation of α-ketothioesters is described. Mono- and double-decarbonylations, which gave thioesters and thioethers, respectively, were selectively achieved by changing the ligand. A fundamental study of Ni-catalyzed decarbonylation of α-ketothioesters is presented.
- Zheng, Zhao-Jing,Jiang, Cheng,Shao, Peng-Cheng,Liu, Wen-Fei,Zhao, Tian-Tian,Xu, Peng-Fei,Wei, Hao
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p. 1907 - 1910
(2019/05/02)
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- Decarbonylative thioetherification by nickel catalysis using air- and moisture-stable nickel precatalysts
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A general, highly selective method for decarbonylative thioetherification of aryl thioesters by C-S cleavage is reported. These reactions are promoted by a commercially-available, user-friendly, inexpensive, air- and moisture-stable nickel precatalyst. The process occurs with broad functional group tolerance, including free anilines, cyanides, ketones, halides and aryl esters, to efficiently generate thioethers using ubiquitous carboxylic acids as ultimate cross-coupling precursors (cf. conventional aryl halides or pseudohalides). Selectivity studies and site-selective orthogonal cross-coupling/thioetherification are described. This thioester activation/coupling has been highlighted in the expedient synthesis of biorelevant drug analogue. In light of the synthetic utility of thioethers and Ni(ii) precatalysts, we anticipate that this user-friendly method will be of broad interest.
- Liu, Chengwei,Szostak, Michal
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supporting information
p. 2130 - 2133
(2018/03/06)
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- Formation of C(sp2)-S bonds through decarboxylation of α-oxocarboxylic acids with disulfides or thiophenols
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Copper-catalyzed decarboxylative coupling between α-oxocarboxylic acids and diphenyl disulfides or thiophenols is presented, which provided an effective and direct approach for the preparation of useful thioesters through C(sp2)-S bond formatio
- Rong, Guangwei,Mao, Jincheng,Liu, Defu,Yan, Hong,Zheng, Yang,Chen, Jie
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p. 26461 - 26464
(2015/03/30)
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- Polymer supported Pd catalyzed thioester synthesis via carbonylation of aryl halides under phosphine free conditions
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A new polymer supported phosphine free Pd(ii) complex has been synthesized and characterized. The catalytic performance of the complex has been tested for the carbonylation of aryl halides into aryl thioesters under mild reaction conditions. Thioesters were obtained in excellent yields from various aryl iodides and thiols in the presence of carbon monoxide and polymer supported palladium catalyst. The effects of solvent, base, reaction time and catalyst amount for the thioester synthesis were reported. This catalyst showed excellent catalytic activity and recyclability. The polymer supported Pd(ii) catalyst could be easily recovered by filtration and reused more than five times without appreciable loss of its initial activity.
- Islam, Sk Manirul,Molla, Rostam Ali,Roy, Anupam Singha,Ghosh, Kajari
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p. 26181 - 26192
(2014/07/08)
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- Tetraethylammonium bromide-catalyzed oxidative thioesterification of aldehydes and alcohols
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A metal-free, tetraethylammonium bromide-catalyzed oxidative coupling of aldehydes or alcohols with thiophenols or disulfides has been developed. This protocol affords an efficient and inexpensive approach to the synthesis of a wide range of thioesters in high yields. Copyright
- Zhu, Xuebin,Shi, Yan,Mao, Haibin,Cheng, Yixiang,Zhu, Chengjian
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supporting information
p. 3558 - 3562
(2014/01/06)
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- Pd-catalyzed thiocarbonylation with stoichiometric carbon monoxide: Scope and applications
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A general protocol for the Pd-catalyzed thiocarbonylation of aryl iodides with stoichiometric carbon monoxide has been established employing a catalytic system composed of Pd(OAc)2 and DPEphos with low catalyst loading (1 mol %). Both electron-rich and -deficient aryl iodides proved effective for these couplings with aryl and alkyl thiols. The choice of the metal ligands and the solvent system was crucial for the efficiency and chemoselectivity of these transformations.
- Burhardt, Mia N.,Taaning, Rolf H.,Skrydstrup, Troels
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supporting information
p. 948 - 951
(2013/03/28)
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