Synthesis of a 3,4-Dihydro-1,3-oxazin-2-ones Skeleton via an Intermolecular [4 + 2] Process of <i>N</i>-Acyliminium Ions with Ynamides/Terminal Alkynes
Xiaoli Han, Xiao-Di Nie, Zhao‐Dan Chen, Yuying Zhang, Bang‐Guo Wei, Guoqiang Lin
Abstract
An approach to access functionalized 3,4-dihydro-1,3-oxazin-2-ones has been developed by reacting semicyclic N,O-acetals 5 and 6 with ynamides 7 or terminal alkynes 8 in a one-pot fashion. The reaction went through a formal [4 + 2] cycloaddition process to generate a number of functionalized 3,4-dihydro-1,3-oxazin-2-ones 9a–9ak and 10a–10bc in yields of 34–97%. In addition, the utility of this transformation was demonstrated by the synthesis of (±)-sedamine 13.
Topics & Concepts
ChemistryCycloadditionIntermolecular forceTerminal (telecommunication)Combinatorial chemistryProcess (computing)StereochemistryMoleculeOrganic chemistryCatalysisComputer scienceOperating systemTelecommunicationsCatalytic Alkyne ReactionsChemical synthesis and alkaloidsCyclopropane Reaction Mechanisms