Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University , 1-13-27 Kasuga, Bunkyo-ku, 112-8551 Tokyo, Japan.
Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, 113-8656 Tokyo, Japan.
J Am Chem Soc. 2016 Mar 16;138(10):3548-52. doi: 10.1021/jacs.6b00283. Epub 2016 Feb 29.
A bora-Brook rearrangement, i.e., the migration of boryl group from a carbon to an oxygen atom in an isolated α-boryl-substituted alkoxide, was examined, and decisive factors for the acceleration of this reaction are disclosed. In this rearrangement, the boryl-substituted alkoxide exhibited ambiphilic reactivity toward electrophiles to afford two types of products, which are electrophiles bound either at the oxygen or at the carbon atom. Using polar solvents, a saturated backbone of the boron-containing heterocycle, or larger alkali metal cations resulted in a significantly increased reaction rate of base-catalyzed isomerization of α-borylbenzyl alcohol including the bora-Brook rearrangement.
研究了一种博拉-布鲁克重排反应，即甲硼烷基从孤立的α-取代甲硼烷基烷氧基中的碳原子迁移到氧原子的过程，并揭示了加速该反应的决定性因素。在这种重排反应中，取代的甲硼烷基烷氧基对亲电试剂表现出两性反应性，生成两种产物，亲电试剂分别与氧原子或碳原子结合。使用极性溶剂、含硼杂环的饱和骨架或较大的碱金属阳离子，可显著提高包括博拉-布鲁克重排反应在内的α-取代甲硼基苄醇的碱催化异构化反应速率。
