Enantioselective Catalytic Aldehyde α‐Alkylation/Semipinacol Rearrangement: Construction of α‐Quaternary‐δ‐Carbonyl Cycloketones and Total Synthesis of (+)‐Cerapicol
作者:Jie Yang、Xiao‐Ming Zhang、Fu‐Min Zhang、Shao‐Hua Wang、Yong‐Qiang Tu、Zhen Li、Xi‐Chao Wang、Hong Wang
DOI:10.1002/anie.202001100
日期:2020.5.25
An enantioselectivealdehyde α-alkylation/semipinacol rearrangement was achieved through organo-SOMO catalysis. The catalytically generated enamine radical cation serves as a carbon radical electrophile that can stereoselectively add to the alkene of an allylic alcohol and initiate ensuing ring-expansion of cyclopropanol or cyclobutanol. This tandem reaction enables the production of a wide range of
Synthesis of the ABC framework of tamulamides A and B
作者:Elizabeth H. Kelley、Timothy F. Jamison
DOI:10.1016/j.bmc.2018.04.046
日期:2018.10
Synthesis of the fused tetrahydrofuran motif comprising the ABC rings of the marine ladder polyethers tamulamides A and B has been achieved via two different polyepoxide cascade strategies. Investigations into a triepoxide cascade under aqueous conditions revealed the importance of the electronic nature of the cascade end-group with this initial approach. Ultimately, a diepoxide cascade under basic
Free radical-mediated vinyl amination: a mild, general pyrrolidinyl enamine synthesis
作者:Benjamin M. Nugent、Amie L. Williams、E.N. Prabhakaran、Jeffrey N. Johnston
DOI:10.1016/j.tet.2003.04.003
日期:2003.11
The complete scope of freeradical-mediated vinyl amination is described, using 5-exo-trig cyclizations of vinyl radicals to the nitrogen of azomethines. The focus is primarily on N,N-dialkyl enamines since their nucleophilicity renders them the most challenging enamines to synthesize using redox conditions. These studies establish several encouraging precedents for the broader application of this