Kaur, Gurpreet; Sinha, Avisikta; Ravikanth, Mangalampalli published their research in Asian Journal of Organic Chemistry in 2021. The article was titled 《Synthesis of Mono β-Pyrrole Substituted Triphyrin(2.1.1)s》.Category: pyridine-derivatives The article contains the following contents:
A series of ten mono β-substituted triphyrin(2.1.1)s I [R = Me, Ph, 4-pyridyl, etc.] were synthesized by coupling mono β-bromo triphyrin(2.1.1) I [R = Br] with appropriate boronic acid in THF/toluene/water (1 : 1 : 1) in the presence of a catalytic amount of Pd(PPh3)4 in 17-67% yields. Different boronic acids such as Me, Ph, p-tolyl, p-anisyl, p-fluorophenyl, p-chlorophenyl, 3-thienyl, 3-pyridyl, 4-pyridyl, p-biphenyl boronic acids were used. This synthetic approach to β-substituted triphyrin(2.1.1)s I was facile. The mono-β-substituted triphyrin(2.1.1)s I were characterized and studied by mass spectrometry, NMR, absorption, electrochem. and DFT/TD-DFT techniques. The spectral studies indicated slight alterations in their electronic properties due to presence of an alkyl/aryl/heteroaryl substituent at the β-pyrrole carbon. DFT studies indicated that the pyrrole ring which was substituted with alkyl group at its β-position exhibited more deviation compared to the other two pyrroles of triphyrin(2.1.1) I macrocycle from the mean plane. However, the β-aryl/heteroaryl substituted pyrrole showed less deviation from the mean plane and overall β-aryl/heteroaryl macrocycle was planar. Furthermore, the studies also supported the participation of a β-substituent with π-delocalization of triphyrin(2.1.1) I. TD-DFT studies support the exptl. observations. The experimental part of the paper was very detailed, including the reaction process of Pyridin-3-ylboronic acid(cas: 1692-25-7Category: pyridine-derivatives)
Pyridin-3-ylboronic acid(cas: 1692-25-7) belongs to pyridine. Pyridine’s structure is isoelectronic with that of benzene, but its properties are quite different. Pyridine is completely miscible with water, whereas benzene is only slightly soluble. Like all hydrocarbons, benzene is neutral (in the acid–base sense), but because of its nitrogen atom, pyridine is a weak base.Category: pyridine-derivatives