2015年4月
para-C-H Borylation of Benzene Derivatives by a Bulky Iridium Catalyst
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
- ,
- ,
- 巻
- 137
- 号
- 15
- 開始ページ
- 5193
- 終了ページ
- 5198
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1021/jacs.5b02052
- 出版者・発行元
- AMER CHEMICAL SOC
A highly para-selective aromatic C-H borylation has been accomplished. By a new iridium catalyst bearing a bulky diphosphine ligand, Xyl-MeO-BIPHEP, the C-H borylation of monosubstituted benzenes can be affected with para-selectivity up to 91%. This catalytic system is quite different from the usual iridium catalysts that cannot distinguish meta- and para-C-H bonds of monosubstituted benzene derivatives, resulting in the preferred formation of meta-products. The para-selectivity increases with increasing bulkiness of the substituent on the arene, indicating that the regioselectivity of the present reaction is primarily controlled by steric repulsion between substrate and catalyst. Caramiphen, an anticholinergic drug used in the treatment of Parkinsons disease, was converted into five derivatives via our para-selective borylation. The present [Ir(cod)OH](2)/Xyl-MeO-BIPHEP catalyst represents a unique, sterically controlled, para-selective, aromatic C-H borylation system that should find use in streamlined, predictable chemical synthesis and in the rapid discovery and optimization of pharmaceuticals and materials.
- リンク情報
- ID情報
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- DOI : 10.1021/jacs.5b02052
- ISSN : 0002-7863
- Web of Science ID : WOS:000353606700053