Access to cyclobutene-fused azepines through Au-catalyzed cycloisomerization of stable alkyne tethered ketene N,N-acetals.
A base promoted reaction between N-protected propargyl amines and 3-bromopropiolate readily provides an array of novel stable alkyne-tethered ketene N,N-acetals in good yields. A wide range of structurally complex cyclobutene-fused azepine heterocycles are synthesized through the gold-catalyzed intramolecular cycloisomerization of ketene N,N-acetals for the first time. A plausible reaction pathway is deduced on the basis of the (1)H NMR studies.
School of Chemistry, University of Hyderabad , Hyderabad-500046, India.
Sanatan
S
Nayak
Nayan
N
Ghosh
Akhila K
AK
Sahoo