Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States.
Org Lett. 2020 Sep 18;22(18):7321-7326. doi: 10.1021/acs.orglett.0c02657. Epub 2020 Sep 9.
The enantioselective synthesis of 6'-boryl-1,2-oxaborinan-3-enes is reported. A Cu-catalyzed highly stereoselective 1,4-protoboration of 1,1-bisboryl-1,3-butadiene is developed to generate ()-α,δ-bisboryl-crotylboronate. The chiral phosphoric-acid-catalyzed asymmetric allylboration of aldehydes with the boron reagent produces 6'-boryl-1,2-oxaborinan-3-enes with excellent Z-selectivities and enantioselectivities. The product contains a vinyl and alkyl boronate unit that can directly participate in a variety of subsequent transformations.
报道了 6'-硼基-1,2-氧杂硼烷-3-烯的对映选择性合成。开发了一种 Cu 催化的 1,1-双硼基-1,3-丁二烯的高对映选择性 1,4-原硼化反应，生成 ()-α,δ-双硼基-烯丙基硼酸酯。手性磷酸催化的硼试剂对醛的不对称烯丙基硼化反应生成了具有优异 Z-选择性和对映选择性的 6'-硼基-1,2-氧杂硼烷-3-烯。产物含有一个乙烯基和烷基硼酸酯单元，可以直接参与多种后续转化。
