@article{oai:kitami-it.repo.nii.ac.jp:00007174,
 author = {Shirakawa, Kazuya and Arase, Akira and Hoshi, Masayuki},
 issue = {11},
 journal = {Synthesis},
 month = {Aug},
 note = {Two synthetic routes to (E)-1-alkenylboronic acid pinacol esters (3) were investigated. Hydroboration of 1-alkynes (1) with 1,3,2-benzodioxaborole (catecholborane), in situ generated by the reaction of BH3 in THF with catechol, proceeded in the presence of a catalytic amount of dicyclohexylborane in THF at room temperature to give the corresponding (E)-1- alkenylboronic acid catechol esters (2). Treatment of the resultant 2 with 2,3-dimethyl-2,3-butanediol (pinacol) easily afforded the desired products 3, which are insensitive to air, moisture and chromatography, in good to high overall yields. The sequential reaction is a highly efficient route to 3 from BH_3 in THF in a one-pot manner. Alternatively, hydroboration of 1 with 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (pinacolborane) was achieved in the presence of a catalytic amount of dicyclohexylborane at room temperature under neat conditions to afford the corresponding 3 directly in good to excellent yields. This route is extremely efficient and environmentally benign from the viewpoints of making good use of pinacolborane and of using no solvent, and is capable of using a variety of 1 including functionalized ones such as HC≡CCH_2Cl and HC≡CCH_2OTHP., application/pdf},
 pages = {1814--1820},
 title = {Preparation of (E)-1-alkenylboronic acid pinacol esters via transfer of alkenyl group from boron to boron.},
 volume = {2004},
 year = {2004}
}