In 2018,Mihai, Madalina T.; Davis, Holly J.; Genov, Georgi R.; Phipps, Robert J. published 《Ion Pair-Directed C-H Activation on Flexible Ammonium Salts: meta-Selective Borylation of Quaternized Phenethylamines and Phenylpropylamines》.ACS Catalysis published the findings.Formula: C7H9NO The information in the text is summarized as follows:
Ion pairing has unexplored potential as a key catalyst-substrate interaction for controlling regioselectivity and site-selectivity in transition-metal catalysis, particularly in the area of C-H activation. However, there is a significant perceived challenge that has meant that few have investigated this approach to date-that of the low directionality, which could present an unsurmountable challenge if seeking positional selectivity on flexible substrates. Herein, we demonstrate that even flexible substrates with several freely rotatable bonds undergo ion pair-directed C-H borylation with good to excellent levels of regiocontrol for the arene meta-position. Furthermore, we demonstrate that in specially designed competition substrates, ion pair direction prevails over competing hydrogen bond direction. We anticipate that these findings will inspire the greater incorporation of ion-pairing into site-selective catalytic strategies. In the experiment, the researchers used 2-(2-Hydroxyethyl)pyridine(cas: 103-74-2Formula: C7H9NO)
2-(2-Hydroxyethyl)pyridine(cas: 103-74-2) belongs to pyridine. Pyridine is a relatively complex molecule and exhibits a number of different bands in IR spectra. Among others, the bands characterizing the ν8a and ν19b modes have been found to be sensitive to the coordination or protonation of the molecule. Note that the band that is diagnostic for the PyH+ ion at about 1545 cm− 1 (ν19b mode) does not overlap with any of the other bands.Formula: C7H9NO