Department of Chemistry , Zhejiang University , Hangzhou 310027 , China.
J Am Chem Soc. 2019 Mar 20;141(11):4558-4563. doi: 10.1021/jacs.9b01124. Epub 2019 Mar 11.
The first Pd(II)-catalyzed enantioselective alkynylation of unbiased methylene β-C(sp)-H bonds is reported. The readily accessible and tunable BINOL derivatives are used as chiral ligands in C-H activation for the first time. 3,3'-Fluorinated-BINOL proved crucial in determining both the reactivity and enantioselectivity. A wide range of carboxylic acid derivatives are well tolerated with high enantioselectivities (up to 96% ee). Mechanistic studies suggest that multiple ligands may participate in the stereodetermining C-H palladation step, and a chiral amplification effect is observed.
首次报道了首例无偏向的亚甲基β-C(sp)-H 键的 Pd(II)催化对映选择性炔基化反应。BINOL 衍生物作为手性配体首次应用于 C-H 活化反应中，具有很好的可及性和可调性。3,3'-氟化-BINOL 在决定反应活性和对映选择性方面至关重要。研究表明，多种羧酸衍生物具有很好的耐受性，对映选择性高（高达 96%ee）。机理研究表明，多个配体可能参与立体确定的 C-H 钯化步骤，并且观察到手性放大效应。
