A Versatile Enantioselective Catalytic Cyclopropanation‐Rearrangement Approach to the Divergent Construction of Chiral Spiroaminals and Fused Bicyclic Acetals
A highly enantioselective synthesis of various chiral heterobicyclic molecules including spiroaminals and fused bicyclic acetals has been developed via a chiral copper catalyzed cyclopropanation‐rearrangement (CP‐RA) approach under mild reaction conditions. Remarkably, the asymmetric CP‐RA for exocyclic vinyl substrates without a pro‐stereogenic carbon at the β‐position has been realized for the first
Rhodium-Catalyzed Regiodivergent [3 + 2] and [5 + 2] Cycloadditions of Quinolinium Ylides with Alkynes
作者:Min He、Nuan Chen、Jian Wang、Shiyong Peng
DOI:10.1021/acs.orglett.9b01765
日期:2019.7.5
Rhodium-catalyzed regiodivergent [3 + 2] and [5 + 2] cycloadditions of quinolinium ylides with alkynes are reported, providing highly functionalized five-membered indolizine derivatives and seven-membered 1,4-oxazepine compounds, respectively, in moderate to excellent yields under mild reaction conditions. Importantly, quinolinium ylides are derived from donor–acceptor diazo compounds, and different
Enantioselective Synthesis of Chiral‐at‐Sulfur 1,2‐Benzothiazines by Cp<sup>x</sup>Rh<sup>III</sup>‐Catalyzed C−H Functionalization of Sulfoximines
作者:Yang Sun、Nicolai Cramer
DOI:10.1002/anie.201810887
日期:2018.11.19
attractive structural motifs in drug discovery. A direct catalytic enantioselective method for the synthesis of sulfur‐chiral 1,2‐benzothiazines from readily accessible diaryl sulfoximines is presented. Rhodium(III) complexes equipped with chiral cyclopentadienyl ligands and paired with suitable carboxylic acid additives engage in an enantiodetermining C−H activation directed by the sulfoximine group. Subsequent