7342-85-0Relevant articles and documents
METHOD FOR SYNTHESIZING SODIUM 2,2,6,6-TETRAMETHYLPIPERIDIDES
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Paragraph 0127; 0130; 0131; 0142; 0143, (2019/12/10)
There is a demand for the development of a technique according to which sodium 2,2,6,6-tetramethylpiperidides (Na-TMPs) can be economically and efficiently synthesized through simple operations including a small number of steps under mild conditions in a short period of time. Also, there is a demand for the development of a technique according to which high-quality Na-TMPs that do not contain lithium or lithium compounds such as Li-TMP can be synthesized. The method for synthesizing sodium 2,2,6,6-tetramethylpiperidides includes a step of obtaining sodium 2,2,6,6-tetramethylpiperidides by reacting, in a reaction solvent, 2,2,6,6-tetramethylpiperidines with a dispersion product obtained by dispersing sodium in a dispersion solvent or an organosodium compound having an aromatic ring obtained through a reaction with a dispersion product obtained by dispersing sodium in a dispersion solvent.
Lithium-Free Synthesis of Sodium 2,2,6,6-Tetramethylpiperidide and Its Synthetic Applications
Asako, Sobi,Kodera, Masato,Nakajima, Hirotaka,Takai, Kazuhiko
supporting information, p. 3120 - 3123 (2019/05/22)
Lithium-free synthetic methods for sodium 2,2,6,6-tetramethylpiperide (NaTMP) have been developed using sodium dispersion as a sole sodium source. The prepared NaTMP was used as a Br?nsted base, that exhibited some differences in reactivities from LiTMP. (Figure presented.).
Room-temperature Suzuki-Miyaura coupling of heteroaryl chlorides and tosylates
Yang, Junfeng,Liu, Sijia,Zheng, Jian-Feng,Zhou, Jianrong
supporting information, p. 6248 - 6259,12 (2020/09/16)
Suzuki-Miyaura coupling of heteroaryls is an important method for the preparation of compound libraries for medicinal chemistry and materials research. Although many catalysts have been developed, none of them have been generally applicable to the coupling reactions of heteroaryl chlorides and tosylates at room temperature. We discovered that a catalyst combination of Pd(OAc)2 and XPhos (2-dicyclohexylphosphanyl-2',4',6'- triisopropylbiphenyl) could efficiently catalyze these couplings. Besides the choice of catalyst, the use of hydroxide bases in an aqueous alcoholic solvent was essential for fast couplings. These conditions promoted fast release of active catalyst (XPhos)Pd0, and accelerated the transmetalation in the catalytic cycle. Most of the major families of heteroaryl chlorides (31 examples) and tosylates (17 examples) reached full conversion within minutes to hours at room temperature. The method could be easily scaled up for gram-scale synthesis. Furthermore, we examined the relative reactivity of coupling partners in whole reactions. Electron-rich heteroaryl chlorides and tosylates reacted more slowly than electron-deficient ones, in the order of indole, pyrrole furan, thiophene > pyridine. Similarly, electron-deficient arylboronic acids were less reactive than electron-neutral and electron-rich ones. The reactivity trends from this study can help to choose appropriate coupling partners for Suzuki reactions.
Modulating reactivity and diverting selectivity in palladium-catalyzed heteroaromatic direct arylation through the use of a chloride activating/blocking group
Liegault, Benoit,Petrov, Ivan,Gorelsky, Serge I.,Fagnou, Keith
supporting information; experimental part, p. 1047 - 1060 (2010/04/04)
(Chemical Equation Presented) Through the introduction of an aryl chloride substituent, the selectivity of palladium-catalyzed direct arylation may be diverted to provide alternative regioisomeric products in high yields. In cases where low reactivity is typically observed, the presence of the carbon-chlorine bond can serve to enhance reactivity and provide superior outcomes. From a strategic perspective, the C-Cl bond is easily introduced and can be employed in a variety of subsequent transformations to provide a wealth of highly functionalized heterocycles with minimal substrate preactivation. The impact of the C-Cl functional group on direct arylation reactivity has also been evaluated mechanistically, and the observed reactivity profiles correlate very well with that predicted by a concerted metalation-deprotonation pathway.
Intramolecular cross-coupling of gem-dibromoolefins: A mild approach to 2-bromo benzofused heterocycles
Newman, Stephen G.,Aureggi, Valentina,Bryan, Christopher S.,Lautens, Mark
supporting information; experimental part, p. 5236 - 5238 (2010/01/31)
Highly useful halogenated benzofurans and benzothiophenes are prepared from readily available gem-dibromoolefins using a mild, ligand-free copper catalyzed cross-coupling procedure.
