Intermolecular [3 + 3]-Cycloadditions of Azides with the Nazarov Intermediate
摘要:
Tetrasubstituted 1,4-dien-3-ones undergo Nazarov cyclization at low temperature, followed by reaction with organic azides via an apparent [3 + 3]-cycloaddition to give bridged bicyclic triazenes. These products do not appear to be intermediates in the previously described Schmidt-type process to furnish dihydropyridones. The reaction typically occurs with high diastereoselectivity.
Intercepting the Nazarov Oxyallyl Intermediate with α-Formylvinyl Anion Equivalents to Access Formal Morita–Baylis–Hillman Alkylation Products
作者:F. West、Yen-Ku Wu、Rongrong Lin
DOI:10.1055/s-0036-1588769
日期:2017.7
catalyzed cationicdomino reaction involving sequential electrocyclization and polar addition of allenol ethers onto the resulting oxyallyl species is described. The overall sequence allows a highly stereoselective synthesis of densely substituted cyclopentanoid compounds containing α-formylvinyl functionality which is formally equivalent to products of a Morita–Baylis–Hillman alkylation process.
Interrupting Nazarov Reaction with Different Trapping Modality: Utilizing Potassium Alkynyltrifluoroborate as a σ-Nucleophile
作者:Ronny William、Siming Wang、Asadulla Mallick、Xue-Wei Liu
DOI:10.1021/acs.orglett.6b01606
日期:2016.9.16
cation intermediate generated following Nazarov cyclization of dienone has been successfully intercepted with potassium alkynyltrifluoroborates which act as σ-nucleophiles in the presence of BF3·Et2O. This new trapping modality allowed unprecedented introduction of an alkynyl moiety to the cyclopentanone framework by means of an interruptedNazarovreaction. The α-alkynyl cyclopentanone product can