Department of Chemistry and Biochemistry, Auburn University, Auburn, AL, 36849, USA.
Angew Chem Int Ed Engl. 2021 Jan 11;60(2):840-848. doi: 10.1002/anie.202006420. Epub 2020 Nov 10.
A Cu-catalyzed regio-, diastereo-, and enantioselective carboboration of 1,1-bisboryl-1,3-butadiene is developed to generate enantioenriched 3,6'-bisboryl-anti-1,2-oxaborinan-3-enes. DFT calculations indicate that the initial diene 1,2-borocupration forms a η-allylic copper as the most stable intermediate. Subsequent aldehyde addition, however, operates under Curtin-Hammett control via a more reactive α,α-bisboryl tertiary allylcopper species to furnish products with high enantioselectivities. The three boryl groups in the products are properly differentiated and can undergo a variety of chemoselective transformations to produce enantioenriched homoallylic alcohols with a stereodefined trisubstituted alkene.
发展了一种铜催化的 1,1-双硼基-1,3-丁二烯的区域、非对映选择性和对映选择性碳硼化反应，以生成对映富集的 3,6'-双硼基-反-1,2-氧杂硼烷-3-烯。DFT 计算表明，初始二烯 1,2-硼铜化形成最稳定的中间体 η-烯丙基铜。然而，随后的醛加成通过更具反应性的α,α-双硼基叔烯丙基铜物种在 Curtin-Hammett 控制下进行，以提供具有高对映选择性的产物。产物中的三个硼基基团得到了适当的区分，并可以进行多种选择性化学反应，以生成具有立体定义的三取代烯烃的对映富集的偕烯丙醇。
