Chiral Hypervalent Bromine(III) (Bromonium Salt): Hydrogen- and Halogen-Bonding Bifunctional Asymmetric Catalysis by Diaryl-λ<sup>3</sup>-bromanes
作者:Yasushi Yoshida、Takashi Mino、Masami Sakamoto
DOI:10.1021/acscatal.1c04070
日期:2021.11.5
Bromonium salts, which are hypervalent bromine reagents, have been explored as being strong electrophiles owing to their extremely high nucleofugalities. Only one example of their catalytic application has been reported by our group; however, their chiral versions have not yet been researched. Halogen-bonding (XB) has been widely applied in chemistry; however, its successful application to highly enantioselective
溴鎓盐是高价溴试剂,由于其极高的离核性,已被研究为强亲电试剂。我们小组只报道了一个催化应用的例子;然而,他们的手性版本尚未被研究。卤素键合(XB)在化学中得到了广泛的应用;然而,其在高对映选择性路易斯酸催化中的成功应用尚未实现。在此,我们报告了手性环状二芳基溴鎓盐的设计和开发。这些催化剂实现了高度对映选择性的路易斯酸 XB 催化,提供了高达 96% ee 的产物。
Copper-Catalyzed Remote Regio- and Enantioselective Yne-Allylic Substitution of Coumarins
the development of straightforward and efficient methodologies for the synthesis of readily functionalized chiral coumarins is of significant interest. Herein we report an enantioselectivecopper-catalyzed yne-allylic substitution of coumarins, resulting in a highly regioselective synthesis of diverse new classes of chiral coumarin derivatives with high efficiency and excellent functional group tolerance