Tunable Diastereoselective Desymmetrization of Cyclohexadienones Triggered by Copper-Catalyzed Three-Component Coupling Reaction
作者:Raghunath Reddy Anugu、Rambabu Chegondi
DOI:10.1021/acs.joc.7b00936
日期:2017.7.7
copper-catalyzed [3 + 2]-cycloaddition followed by ketenimine formation and subsequent intramolecular conjugate addition. The cascade reaction provides cis-hydrobenzofurans in good yields with excellent diastereoselectivity. The exo- or endo-selectivity of bicyclic scaffolds depends on the selection of the base in the reaction. In addition, N-tethered bicyclic products further transformed into tricyclic compounds
Efficient Access to Bicyclo[4.3.0]nonanes: Copper‐Catalyzed Asymmetric Silylative Cyclization of Cyclohexadienone‐Tethered Allenes
作者:Zhi‐Tao He、Xiao‐Qi Tang、Li‐Bo Xie、Mian Cheng、Ping Tian、Guo‐Qiang Lin
DOI:10.1002/anie.201508125
日期:2015.12
silylative cyclization of cyclohexadienone‐tethered allenes. Through regioselective β‐silylation of the allene and subsequent enantioselective 1,4‐addition to cyclohexadienone, this tandem reaction could afford cis‐hydrobenzofuran, cis‐hydroindole, and cis‐hydroindene frameworks with excellent yields (80–98 %) and enantioselectivities (94–98 % ee) bearing vinylsilane and enone substructures. Meanwhile,
Silver(I)-Catalyzed Enyne Cyclization/Aromatization of Alkyne-Tethered Cyclohexadienones to Access Meta-Substituted Phenols
作者:Anandarao Munakala、Rambabu Chegondi
DOI:10.1021/acs.orglett.0c03819
日期:2021.1.15
Herein we report a highly regioselective silver(I)-catalyzed intramolecular annulation of alkyne-tethered cyclohexadienones to access meta-substituted phenols with enone functionality, which are difficult to synthesize from conventional methods. The reaction proceeds via intramolecular 1,6-enyne cyclization followed by aromatization and subsequent oxetene ring rearrangement. This strategy has also
tricyclic enones with high diastereoselectivity. In the case of C-tethered cyclohexadienones, the reaction proceeds further via acid mediated semipinacol-type rearrangement to give complex and highly strained tricyclo[3.3.1.0]nonanediones. This cascade annulation has wide functional-group tolerance and broad substrate scope. Late-stage functionalization of estrone was also demonstrated with excellent
Enantioselective Construction of Functionalized Tetrahydrocarbazoles Enabled by Asymmetric Relay Catalysis of Gold Complex and Chiral Brønsted Acid
作者:Feng Zhao、Nan Li、Yi-Fan Zhu、Zhi-Yong Han
DOI:10.1021/acs.orglett.6b00012
日期:2016.4.1
An intramolecular hydroamination/Michael addition cascade is realized using a combination of gold(I) complex and chiralBINOL–phosphoricacid, affording fused-tetrahydrocarbazole scaffolds in excellent yields and high enantioselectivities.