Planar Chiral [2.2]Paracyclophane-Based Bisoxazoline Ligands: Design, Synthesis, and Use in Cu-Catalyzed Inter- and Intramolecular Asymmetric O–H Insertion Reactions
作者:Shinji Kitagaki、Shunsuke Murata、Kisaki Asaoka、Kenta Sugisaka、Chisato Mukai、Naoko Takenaga、Keisuke Yoshida
DOI:10.1248/cpb.c18-00519
日期:2018.10.1
insertion reactions of α-diazo esters. The reactivities and enantioselectivities of Cu complexes of the synthesized bisoxazoline ligands were lower than those of ligands without central chirality. However, planar chiral [2.2]paracyclophane-based bisoxazoline ligands with an inserted benzene spacer that had a sterically demanding isopropyl substituent showed good enantioselectivities in inter- and intramolecular
Organocatalyzed Asymmetric Synthesis of Dihydrodibenzofurans Based on a Dienamine Process
作者:Zi-Yu Wang、Wing-Tak Wong、Dan Yang
DOI:10.1021/ol402288y
日期:2013.10.4
The first organocatalyzed asymmetric method for the synthesis of dihydrodibenzofurans based on a dienamine process has been developed. This two-step protocol works with a broad range of substrates and delivers only the cis-diastereomer in good yield with up to 91% ee. The enantioenriched products have been transformed to highly functionalized and partially hydrogenated dibenzofurans in excellent diastereoselectivities.