Synthesis and Chemistry of Donor/Acceptor-Substituted Cyclopropenes
摘要:
Rhodium(II) acetate, or trifluoroacetate-catalyzed decomposition of 1-diazo-2-(trialkylsiloxy)propenes with electron-withdrawing groups at the 1-position results in the formation of highly reactive cyclopropenes. These cyclopropenes contain both donor and acceptor substituents on the alkene and are very susceptible to ring opening and fragmentation reactions, Nevertheless, when appropriately functionalized with bulky substituents they can be of sufficient stability to be isolated and characterized.
Catalytic Desymmetric Cycloaddition of Diaziridines with Metalloenolcarbenes: The Role of Donor–Acceptor Cyclopropenes
作者:Haifeng Zheng、Michael P. Doyle
DOI:10.1002/anie.201906754
日期:2019.9.2
A chiral copper(I) complexcatalyzesreactions of symmetric diaziridines with enol diazo compounds, which react through N-N bond ringopening in a formal [3+3] cycloaddition to form four chiral centers with high stereocontrol. A broad spectrum of bridged dinitrogen heterocycles were obtained in high yields and excellent diastereo- and enantioselectivities from γ-substituted enol diazoacetates, while