107918-19-4Relevant academic research and scientific papers
Site-Specific Oxidative C-H Chalcogenation of (Hetero)Aryl-Fused Cyclic Amines Enabled by Nanocobalt Oxides
Tan, Zhenda,Liang, Yantang,Yang, Jian,Cao, Liang,Jiang, Huanfeng,Zhang, Min
, p. 6554 - 6558 (2018)
By employing reusable nanocobalt oxides as the catalysts, a site-specific oxidative C-H chalcogenation of (hetero)aryl-fused cyclic amines with various thiols and diselenides is presented for the first time. The reaction proceeds selectively at the sites of the (hetero)aryl rings para to the N atom, and enables access to a wide array of chalcogenyl N-heteroarenes. The merits of the transformation involve high step- and atom-efficiency, excellent substrate and functional compatibility, operational simplicity, and the use of a naturally abundant Co/O2 system. The present work has offered a fundamental basis for the selective synthesis of functional N-heteroarenes from readily available feedstocks.
Dimsyl Anion Enables Visible-Light-Promoted Charge Transfer in Cross-Coupling Reactions of Aryl Halides
Pan, Lei,Cooke, Maria Victoria,Spencer, Amara,Laulhé, Sébastien
, p. 420 - 425 (2021/11/01)
A methodology is reported for visible-light-promoted synthesis of unsymmetrical chalcogenides enabled by dimsyl anion in the absence of transition-metals or photoredox catalysts. The cross-coupling reaction between aryl halides and diaryl dichalcogenides proceeds with electron-rich, electron-poor, and heteroaromatic moieties. Mechanistic investigations using UV-Vis spectroscopy, time-dependent density functional theory (TD-DFT) calculations, and control reactions suggest that dimsyl anion forms an electron-donor-acceptor (EDA) complex capable of absorbing blue light, leading to a charge transfer responsible for generation of aryl radicals from aryl halides. This previously unreported mechanistic pathway may be applied to other light-induced transformations performed in DMSO in the presence of bases and aryl halides.
Decarbonylative thioetherification by nickel catalysis using air- and moisture-stable nickel precatalysts
Liu, Chengwei,Szostak, Michal
, p. 2130 - 2133 (2018/03/06)
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.
Carbon-sulfur bond formation of challenging substrates at low temperature by using Pd-PEPPSI-IPent
Sayah, Mahmoud,Organ, Michael G.
supporting information; experimental part, p. 11719 - 11722 (2011/11/29)
Aryl thiols made cool and quick: The coupling of alkyl, aryl, and silyl thiols to hindered, deactivated aryl bromides and chlorides has been achieved under the most mild temperatures yet reported (i.e., room temperature to 40°C). The bulk afforded by the di-2,6-(3-propylphenyl)imidazolium-derived Pd-PEPPSI-IPent catalyst is believed to actively promote the critical reductive elimination step of the catalytic cycle, thereby eliminating the formation of poisonous off-cycle dimeric resting states that have plagued Pd-catalyzed sulfination reactions.
