73318-83-9Relevant articles and documents
Catalyst-Free Decarbonylative Trifluoromethylthiolation Enabled by Electron Donor-Acceptor Complex Photoactivation
Lipp, Alexander,Badir, Shorouk O.,Dykstra, Ryan,Gutierrez, Osvaldo,Molander, Gary A.
supporting information, p. 3507 - 3520 (2021/06/11)
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.).
Asymmetric Conjugate Addition of α-Cyanoketones to Benzoyl Acrylonitrile Derivatives Using a Diaminomethylenemalononitrile Organocatalyst
Akutsu, Hiroshi,Nakashima, Kosuke,Kanetsuna, Yuta,Kawada, Masahiro,Hirashima, Shin-Ichi,Miura, Tsuyoshi
, p. 3874 - 3880 (2020/10/06)
A diaminomethylenemalononitrile (DMM) organocatalyst was used to efficiently promote asymmetric conjugate addition of various α-cyanoketones to benzoyl acrylonitrile derivatives. The corresponding 1,5-dicarbonyl compounds containing vicinal tertiary and quaternary stereogenic centers are versatile synthetic intermediates and were obtained in good yields and with excellent enantioselectivities (up to 96% ee). The present study describes the first successful examples of asymmetric conjugate addition reactions of α-cyanoketones with benzoyl acrylonitriles. In addition, the DMM organocatalyst can be recovered and reused up to five times without significant loss of either catalytic activity or enantioselectivity.
Oxidative C-C Bond Cleavage for the Synthesis of Aryl Carboxylic Acids from Aryl Alkyl Ketones
Xu, Liang,Wang, Shengpeng,Chen, Bajin,Li, Meichao,Hu, Xinquan,Hu, Baoxiang,Jin, Liqun,Sun, Nan,Shen, Zhenlu
supporting information, p. 1505 - 1509 (2018/05/25)
A metal-free and one-pot two-step synthesis of aryl carboxylic acids from aryl alkyl ketones has been achieved. The reactions were performed with iodine as the catalyst, DMSO and TBHP as the oxidants. Under the optimal reaction conditions, a number of aryl alkyl ketones could be converted into their corresponding aryl carboxylic acids in good to excellent yields (up to 94%).