Copper-Catalyzed γ-Selective and Stereospecific Substitution Reaction of Allylic Carbonates with Diboron: Efficient Route to Chiral Allylboron Compounds
作者:Hajime Ito、Chika Kawakami、Masaya Sawamura
DOI:10.1021/ja056099x
日期:2005.11.23
copper-catalyzed gamma-selective and stereospecific substitution reaction of allylic carbonates with a diboron reagent affording allylboron compounds is described. Boryl group was selectively introduced at the gamma-position of the leaving carbonate group. Functionalized allylboronates that have an acetal, ester, or isolated alkene were prepared. The reaction of optically active allylic carbonates underwent complete
Practical procedure for copper(I)-catalyzed allylic boryl substitution with stoichiometric alkoxide base
作者:Hajime Ito、Takanori Miya、Masaya Sawamura
DOI:10.1016/j.tet.2011.08.081
日期:2012.4
We have developed a useful procedure for borylation using catalytic CuCl/Xantphos and stoichiometric K(O-t-Bu): the highly versatile method is suitable for the synthesis of allylboronates including those with terminal and internal allylic systems, cyclic structures, and functional groups. Optically active allylboronates were synthesized from prochiral substrates with a chiral diphosphine ligand using this procedure. The reaction rate is generally higher than the original Cu(O-t-Bu)/ligand catalyst system, which we previously reported. (C) 2011 Elsevier Ltd. All rights reserved.