Structural Requirements of 1-(2-Pyridinyl)-5-pyrazolones for Disproportionation of Boronic Acids

We observed an unusual formation of four-coordinate boron(III) complexes from the reaction of 1-(2-pyridinyl)-5-pyrazolone derivatives with arylboronic acids in the basic media. The exact mechanism is not clear; however, the use of unprotected boronic acid and the presence of a bidentate ligand appe...

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Bibliographic Details
Main Authors: Joungmo Cho, Venkata Subbaiah Sadu, Yohan Han, Yunsoo Bae, Hwajeong Lee, Kee-In Lee
Format: Article
Language:English
Published: MDPI AG 2021-11-01
Series:Molecules
Subjects:
Online Access:https://www.mdpi.com/1420-3049/26/22/6814
Description
Summary:We observed an unusual formation of four-coordinate boron(III) complexes from the reaction of 1-(2-pyridinyl)-5-pyrazolone derivatives with arylboronic acids in the basic media. The exact mechanism is not clear; however, the use of unprotected boronic acid and the presence of a bidentate ligand appeared to be the key structural requirements for the transformation. The results suggest that base-promoted disproportionation of arylboronic acid with the assistance of the [<i>N</i>,<i>O</i>]-bidentate ligation of 1-(2-pyridinyl)-5-pyrazolone should take place and facilitate the formation of pyrazole diarylborinate. Experiments to obtain a deeper understanding of its mechanism are currently underway.
ISSN:1420-3049