26891-64-5Relevant academic research and scientific papers
Terminal pyridine-N ligation at [FeFe] hydrogenase active-site mimic
Zhang, Yue,Hu, Ming-Qiang,Wen, Hui-Min,Si, You-Tao,Ma, Cheng-Bing,Chen, Chang-Neng,Liu, Qiu-Tian
, p. 2576 - 2580 (2009)
Diiron model complexes (μ-pdt)Fe2(CO)5L with L = pyridine ligands, e.g. py (A), etpy (B), btpy (C), were synthesized as active site analogues of [FeFe] hydrogenase, and characterized by X-ray crystallography and electrochemistry. Pyr
Ni(II) Precatalysts Enable Thioetherification of (Hetero)Aryl Halides and Tosylates and Tandem C?S/C?N Couplings
Martín, M. Trinidad,Marín, Mario,Maya, Celia,Prieto, Auxiliadora,Nicasio, M. Carmen
supporting information, p. 12320 - 12326 (2021/08/09)
Ni-catalyzed C?S cross-coupling reactions have received less attention compared with other C-heteroatom couplings. Most reported examples comprise the thioetherification of most reactive aryl iodides with aromatic thiols. The use of C?O electrophiles in this context is almost uncharted. Here, we describe that preformed Ni(II) precatalysts of the type NiCl(allyl)(PMe2Ar’) (Ar’=terphenyl group) efficiently couple a wide range of (hetero)aryl halides, including challenging aryl chlorides, with a variety of aromatic and aliphatic thiols. Aryl and alkenyl tosylates are also well tolerated, demonstrating, for the first time, to be competent electrophilic partners in Ni-catalyzed C?S bond formation. The chemoselective functionalization of the C?I bond in the presence of a C?Cl bond allows for designing site-selective tandem C?S/C?N couplings. The formation of the two C-heteroatom bonds takes place in a single operation and represents a rare example of dual electrophile/nucleophile chemoselective process.
Nucleophilic Displacement of Primary Amino Groups via 1-Substituted 4-Tosylimidazoles
Taylor, Edward C.,LaMattina, John L.,Tseng, Chi-Ping
, p. 2043 - 2047 (2007/10/02)
Two methods are discribed for the replacement of primary amino groups, situated either α or γ to a heterocyclic nitrogen atom, by ethoxy, alkylthio, and arylthio substituents, by Wittig reagents, and by hydrogen.Both methods involve transformation of the primary amino group into a nucleofugic pendant heterocycle.The first converts the primary amino group into a 5-phenyl-1-tetrazolyl substituent by benzoylation, formation of the imidoyl chloride, and reaction with sodium azide, while the second converts the primary amino group into a 1-(4-tosylimidazolyl) substituent by reaction with triethyl orthoformate and acid to give the (ethoxymethylene)amino derivative, which is then condensed with tosylmethyl isocyanide (TosMIC) anion.The 1-(4-tosylimidazolyl) substituent is shown to be more susceptible to nucleophilic displacement by a wider range of nucleophiles.
Synthetic Applications of N-N Linked Heterocycles. Part 12. The Preparation of 4-Alkylthio- and 4-Arylthio-pyridines by Regiospecific Attack of Thioalkoxide Ions on N-(4-Oxopyridin-1-yl)pyridinium Salts
Sammes, Michael P.,Leung, Christopher W. F.,Mak, Chi Keung,Katritzky, Alan R.
, p. 1585 - 1590 (2007/10/02)
Thiolate ions add regiospecifically to N-(4-oxopyridin-1-yl)pyridinium salts (2)-(7) to give in good to excellent yields only the 1,4-dihydropyridine adducts (8)-(13), regardless of whether or not the pyridone moiety carries substituents for sterically shielding the 2- and 6-positions of the pyridinium ring.The addition is believed to be thermodynamically controlled.Decomposition of the dihydro-adducts under free-radical conditions, or by pyrolysis, gives good yields of pyridin-4-yl thioethers (14) and (16) though the reaction failed with the 2-methyl adducts (9).An improved synthesis of 6-methyl-4-oxopyran-2-carboxylic acid is also described.
