Rh(III)-Catalyzed Annulation of 2-Biphenylboronic Acid with Diverse Activated Alkenes
作者:Bingxian Liu、Lingyun Yang、Zhenzhen Dong、Junbiao Chang、Xingwei Li
DOI:10.1021/acs.orglett.1c02597
日期:2021.9.17
the reductive elimination process prior to protonolysis, affording the [4 + 2] annulated products instead of the simple 1,4-addition product. Seven-membered rings were obtained when disubstituted cyclopropenones were employed. Bridged cycles were isolated from the coupling of 2-biphenylboronic acid with benzoquinones as a result of 2-fold Michaeladditions. The substrate scopes were found to be broad
-catalyzed asymmetric1,3-dipolarcycloaddition using β-fluoroalkyl alkenyl arylsulfones as dipolarophiles and glycine/alanine iminoesters as azomethineylide precursors has been developed. Remarkably, a catalyst loading as low as 0.5 mol % is highly efficient. Accordingly, a wide range of enantioenriched 3-fluoroalkyl pyrrolidines, as well as Δ2 -pyrroline and pyrrole derivatives, are generated in good
copper‐catalyzed regio‐reversed asymmetric [3+2] cycloaddition of iminoesters with nitroolefins is disclosed for the first time. This method enables the facile synthesis of polysubstituted chiral pyrrolidines bearing at least one chiral quaternary center in high yields with excellent regio‐, diastereo‐, and enantioselectivity. The application of chiral P,S ligands and the unique effect of α‐aryl groups