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Structural Requirements of 1-(2-Pyridinyl)-5-pyrazolones for Disproportionation of Boronic Acids |
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| Authors: | Joungmo Cho Venkata Subbaiah Sadu Yohan Han Yunsoo Bae Hwajeong Lee Kee-In Lee |
| Institution: | 1.Korea Research Institute of Chemical Technology, Daejeon 34114, Korea; (J.C.); (Y.H.);2.R&D Center, Molecules & Materials Co., Ltd., B-219 Daeduck BIZ Center, Daejeon 34013, Korea;3.Department of Life Science, Ewha Womans University, Seoul 03760, Korea;4.Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 03760, Korea; |
| Abstract: | 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 N,O]-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. |
| Keywords: | 1-(2-pyridinyl)-5-pyrazolone [N O]-bidentate ligand arylboronic acid base diarylborination four-coordinate boron(III) complex |