Kim Minjae, Kim Gwanggyun, Kim Doyoon, Cho Seung Hwan
Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
Institute for Convergence Research and Education in Advanced Technology (I-CREATE), Yonsei University, Seoul 03722, Republic of Korea.
J Am Chem Soc. 2024 Dec 18;146(50):34861-34869. doi: 10.1021/jacs.4c14150. Epub 2024 Dec 6.
We report a copper-catalyzed regio-, diastereo-, and enantioselective allylic alkylation of allyl bromides using 1,1-diborylalkanes as prochiral nucleophiles. This methodology employs copper(I) bromide as a catalyst, an ()-BINOL-derived phosphoramidite as a ligand, and lithium benzoate as a crucial additive. The reaction affords enantioenriched homoallylic boronic esters possessing vicinal stereocenters in good yields and high diastereo- and enantioselectivity. The developed method demonstrates a broad substrate scope with respect to a wide range of 1,1-diborylalkanes and allyl bromides. Mechanistic studies, including deuterium-labeling experiments and DFT calculations, provide insights into the reaction pathway and the origin of the stereoselectivity. The synthetic utility of this method is showcased through various transformations of the obtained enantioenriched homoallylic boronic esters into valuable chiral building blocks.
我们报道了一种铜催化的区域、非对映体和对映体选择性烯丙基溴的烯丙基烷基化反应，该反应使用1,1-二硼基烷作为前手性亲核试剂。该方法采用溴化亚铜作为催化剂、（）-联萘酚衍生的亚磷酰胺作为配体，并使用苯甲酸锂作为关键添加剂。该反应能以良好的产率以及高非对映体和对映体选择性得到具有相邻立体中心的对映体富集的高烯丙基硼酸酯。所开发的方法对于各种1,1-二硼基烷和烯丙基溴显示出广泛的底物范围。包括氘标记实验和密度泛函理论计算在内的机理研究为反应途径和立体选择性的起源提供了深入见解。通过将所获得的对映体富集的高烯丙基硼酸酯进行各种转化，制得有价值的手性结构单元，展示了该方法的合成实用性。
