Facile Access to Ring-Fused Aminals via Direct α-Amination of Secondary Amines with o-Aminobenzaldehydes: Synthesis of Vasicine, Deoxyvasicine, Deoxyvasicinone, Mackinazolinone, and Ruteacarpine
摘要:
Secondary amines undergo redox-neutral reactions with aminobenzaldehydes under conventional and microwave heating to furnish polycyclic aminals via amine alpha-amination/N-alkylation. This unique alpha-functionalization reaction proceeds without the involvement of transition metals or other additives. The resulting aminal products are precursors for various quinazolinone alkaloids and their analogues.
Redox Condensations of <i>o</i>-Nitrobenzaldehydes with Amines under Mild Conditions: Total Synthesis of the Vasicinone Family
作者:Oleg I. Afanasyev、Evgeniya Podyacheva、Alexander Rudenko、Alexey A. Tsygankov、Maria Makarova、Denis Chusov
DOI:10.1021/acs.joc.0c00794
日期:2020.7.17
A totalsynthesis of the vasicinone family of natural products from bulk chemicals was developed. Reductive condensation of o-nitrobenzaldehydes with amines utilizing iron pentacarbonyl as a reducing agent followed by subsequent oxidation leads to a great variety of polycyclic nitrogen-containing heterocycles under mild conditions. Enantiomerically pure vasicinone, rutaecarpine, isaindigotone, and