69645-12-1Relevant academic research and scientific papers
Palladium-catalyzed methylation of terminal alkynes
Wang, Wei-Feng,Wu, Xiao-Feng
, (2019/10/22)
In this communication, a palladium-catalyzed procedure for the methylation of terminal alkynes has been developed. With N,N,N-trimethylbenzenaminium trifluoromethanesulfonate as the methyl source, various desired products were obtained in moderate to good yields. Both aromatic and aliphatic alkynes are applicable.
Direct Synthesis of 1-Arylprop-1-ynes with Calcium Carbide as an Acetylene Source
Gao, Lei,Li, Zheng
supporting information, p. 1580 - 1584 (2019/08/20)
A simple method is described for the synthesis of 1-arylprop-1-ynes directly from aromatic aldehyde p -tosylhydrazones by using calcium carbide as an acetylene source. The salient features of this protocol are its use of a readily available and easily handled source of acetylene, its operational simplicity, its high yield, and its broad substrate scope.
Palladium-Catalyzed Tunable Carbonylative Synthesis of Enones and Benzofulvenes
Peng, Jin-Bao,Wu, Fu-Peng,Spannenberg, Anke,Wu, Xiao-Feng
supporting information, p. 8696 - 8700 (2019/08/01)
A palladium-catalyzed four-component carbonylative coupling reaction involving aryl halides, internal alkynes, arylboronic acids, and CO has been developed for the first time. All-carbon substituted α-unsaturated ketones and benzofulvenes can be selectively obtained in a highly regio- and stereocontrolled manner. Using Cu(TFA)2 as the additive, a series of tetrasubstituted α-unsaturated ketones were prepared in moderate to high yields. Using more acidic Lewis acid Cu(OTf)2 as the additive, multisubstituted benzofluvenes were synthesized in moderate yields. This efficient methodology involved the formation of three new C?C bonds, and provided a divergent method for the quick construction of multisubstituted α-unsaturated ketones and benzofulvenes from easily available starting materials.
Controlled Single and Double Iodofluorination of Alkynes with DIH- and HF-Based Reagents
Pfeifer, Lukas,Gouverneur, Véronique
supporting information, p. 1576 - 1579 (2018/03/23)
A novel protocol for the regio- and stereoselective iodofluorination of internal and terminal alkynes using 1,3-diiodo-5,5,-dimethylhydantoin and HF-based reagents is disclosed. This approach is used to prepare a fluorinated tamoxifen derivative in two steps from commercially available starting materials. A facile method enabling controlled regioselective double iodofluorination of terminal alkynes is also presented.
Visible-Light-Mediated Photoredox-Catalyzed Regio- and Stereoselective Chlorosulfonylation of Alkynes
Chakrasali, Prashant,Kim, Kyuneun,Jung, Young-Sik,Kim, Hyejin,Han, Soo Bong
supporting information, p. 7509 - 7513 (2019/01/03)
Herein, a one-step chlorosulfonylation of alkynes via a photocatalytic redox process is described. A variety of commercially available sulfonyl chlorides can be applied for the generation of sulfonyl radical species under visible-light irradiation. Regio- and stereoselective addition of the sulfonyl radical and chloride leads to the efficient formation of (E)-selective β-chlorovinyl sulfones from a broad range of terminal and internal alkynes. The reported method represents an operationally simple and mild way to furnish vinyl sulfones.
Multicomponent Oxidative Trifluoromethylation of Alkynes with Photoredox Catalysis: Synthesis of α-Trifluoromethyl Ketones
Malpani, Yashwardhan R.,Biswas, Bishyajit Kumar,Han, Hong Sik,Jung, Young-Sik,Han, Soo Bong
supporting information, p. 1693 - 1697 (2018/04/16)
The direct oxidative addition of CF3 and H2O to alkynes was achieved with photoredox catalysis to obtain α-trifluoromethyl ketones via rapid enol-keto tautomerization. The reaction exhibits high functional group tolerance and regioselectivity. Heterocycles of various sizes containing CF3 were synthesized from the α-CF3-substituted diketones obtained through the protocol, thereby demonstrating the versatile applicability of the method. Mechanistic studies of the reaction with isotopes provided insight into the reaction pathway.
Rhodium-Catalyzed Intermolecular Carbonylative [2 + 2 + 1] Cycloaddition of Alkynes Using Alcohol as the Carbon Monoxide Source for the Formation of Cyclopentenones
Kim, Ju Hyun,Song, Taemoon,Chung, Young Keun
supporting information, p. 1248 - 1251 (2017/03/14)
A highly regioselective rhodium-catalyzed intermolecular carbonylative [2 + 2 + 1] cycloaddition of alkynes using alcohol as a CO surrogate to access 4-methylene-2-cyclopenten-1-ones has been developed. In this transformation, the alcohol performs multiple roles, including generating the Rh-H intermediate, functioning as the CO source, and assisting in the isomerization of the alkyne. Alkynes can act as both the olefin and the alkyne partner in the cyclopentenone core.
Stereoselective Photoredox-Catalyzed Chlorotrifluoromethylation of Alkynes: Synthesis of Tetrasubstituted Alkenes
Han, Hong Sik,Lee, Young Jin,Jung, Young-Sik,Han, Soo Bong
supporting information, p. 1962 - 1965 (2017/04/28)
A new photoredox-catalyzed chlorotrifluoromethylation reaction of internal arylalkynes under mild conditions using visible light has been developed. The reactions proceed with high levels of regio- and stereoselectivity and utilize commercially available CF3SO2Cl as both the CF3 and Cl source. In the mechanistic pathway for this process, generation of the CF3 radical and chloride ion occurs by Ir(ppy)3-photocatalyzed reductive decomposition of CF3SO2Cl. The synthetically important trifluoromethyl-substituted vinyl chlorides produced in this process can be readily transformed to 1,1-bis-arylalkenes by using Suzuki coupling.
Photoredox-Catalyzed Stereoselective Conversion of Alkynes into Tetrasubstituted Trifluoromethylated Alkenes
Tomita, Ren,Koike, Takashi,Akita, Munetaka
supporting information, p. 12923 - 12927 (2015/11/02)
A regio- and stereoselective synthesis of trifluoromethylated alkenes bearing four different substituents has been developed. Stereocontrolled sulfonyloxytrifluoromethylation of unsymmetric internal alkynes with an electrophilic CF3 reagent, namely the triflate salt of the Yagupol'skii-Umemoto reagent, in the presence of an Ir photoredox catalyst under visible-light irradiation afforded trifluoromethylalkenyl triflates with well-predictable stereochemistry resulting from anti addition of the trifluoromethyl and triflate groups. Subsequent palladium-catalyzed cross-couplings led to tetrasubstituted trifluoromethylated alkenes in a highly stereoselective manner. The present method is the first example of a facile one-pot synthesis of tetrasubstituted trifluoromethylated alkenes from simple alkynes.
Palladium-catalyzed methylation of alkynyl C(sp)-H bonds with dimethyl sulfonium ylides
Liu, Yan-Yun,Yang, Xu-Heng,Huang, Xiao-Cheng,Wei, Wen-Ting,Song, Ren-Jie,Li, Jin-Heng
, p. 10421 - 10426 (2013/11/06)
A novel palladium-catalyzed methylation protocol for the synthesis of methyl-functionalized internal alkynes has been established. This methylation method is achieved through a C(sp)-C(sp3) bond formation process and represents a new synthetic application of sulfonium ylides.
