Asymmetric Boration of Chalcones Catalyzed by Bifunctional[2.2]Paracyclophane-Based N-Heterocyclic Carbene

Meng Ye, Panpan Shen, Wenzeng Duan, Chun Song, Yudao Ma
2017 Youji huaxue  
a 山东大学化学与化工学院 济南 250100) ( b 聊城大学化学与化工学院 聊城 252000) 摘要 为了达到无金属催化的不对称硼化反应高选择性的目的, 设计并合成了基于[2.2]对环蕃的手性氮杂环卡宾前驱 体. 应用该双功能的卡宾催化剂实现了商业化的联硼酸频哪醇酯[B 2 (pin) 2 ]对查尔酮的不对称加成反应, 得到了高达 99%收率和 97%对映体选择性的有机硼化合物. 研究还发现, 水作为添加物在该反应中发挥关键作用. 关键词 有机催化; 不对称催化; 卡宾; 硼化合物; [2.2]对环蕃 Abstract A robust chiral N-heterocyclic carbene precursor based on [2.2]paracyclophane was designed and synthesized for a highly enantioselective metal-free catalytic boration. Enantioselective 1,4-addition of a commercially available
more » ... ly available bis(pinacolato)diboron (B 2 (pin) 2 ) to chalcones was achieved by using the new bifunctional chiral carbene as catalyst, affording the corresponding products in up to 99% yield and 97% enantiomeric excess. Moreover, it was found that water used as the additive plays a key role in the carbene-catalyzed enantioselective boration.
doi:10.6023/cjoc201706035 fatcat:xrctlwjpkfhe3pj5cvxaawmetm