52693-58-0Relevant academic research and scientific papers
Carbon-sulfur and carbon-selenium double bond formation through thiolysis and selenolysis of 4-methylsulfanyl-substituted pyridinium and quinolinium halides
Levillain, Jocelyne,Paquer, Daniel,Sene, Aboubacary,Vazeux, Michel
, p. 99 - 104 (1998)
4-Methylsulfurylpyridinium and -quinolinium salts 3 and 4 with alkyl groups such as methyl, allyl, benzyl, ethoxycarbonylmethyl, benzoylmethyl on the nitrogen atom were prepared by the Menschutkin-type reaction and some of them caused to react under either the thiolysis or selenolysis reaction conditions. N-Substituted pyridine-4-thiones 5a-c and quinoline-4-thiones 6a-e were formed at different rates in high isolated yield. On the other hand, two N-alkyl-4-selenopyridone 7a,b together with three 4-selenoquinolones 8a,b,c were also produced in high chemical purity and characterized spectroscopically. In addition, 4-sulfanylpyridone 12 and 4-selenopyridone 13 with a N-tert-butyl group were obtained via Zincke' s salt 9. The overall process provides a useful alternative to the otherwise difficult direct N-alkylation of thioxo- and selenoxopyridine systems.
Powerful bispyridinylidene organic reducing agents with iminophosphorano π-donor substituents
Hanson, Samuel S.,Richard, Nicholas A.,Dyker, C. Adam
supporting information, p. 8052 - 8055 (2015/05/27)
Four members of a new family of powerful bispyridinylidene organic reducing agents have been prepared, which exploit iminophosphorano (-N=PR3; R=Ph, Cy) π-donor substituents. Electrochemical studies show exceptionally high oxidation potentials, ranging from 1.30 to 1.51 V versus SCE. These new reductants were shown to effectively convert 1-bromonaphthalene to naphthalene under mild reaction conditions. From the redox potentials, substituent constants (σp+) for the iminophosphorano groups Ph3P=N- (-1.82) and Cy3P=N- (-2.21) were determined, demonstrating their superior π-donating properties compared to traditional amino substituents. Extra push: Iminophosphorano groups are utilized to significantly increase the reducing power in a new class of neutral, ground state, organic reducing agents (2; see scheme). In comparative reductions involving reductants of type 1 and 2, the latter allow for shorter reaction times and milder conditions. The superb π-donating properties of the studied iminophosphorano groups were quantified by the determination of their Hammett substituent constants.
