imine → azomethine ylide → cycloaddition cascades. Acid catalysed cyclisations of the NH group of the pyrrolidine products onto the ketone functionality results in novel tri- and tetra-cyclic nitrogenheterocycles.
<i>N</i>-phenyl-substituted pyrrolidines, piperidines and azabicyclics by a tandem reduction-double reductive amination reaction
作者:Richard A. Bunce、Derrick M. Herron、Jason R. Lewis、Sharadsrikar V. Kotturi
DOI:10.1002/jhet.5570400115
日期:2003.1
formed in high yield and are easily purified. The method has also been extended to the synthesis of fused N-phenylazabicyclics from 2-(3-oxo-propyl)cycloalkanones. A high degree of diastereoselectivity for the trans-fused product is observed in substrates having an ester group α to the cycloalkanone carbonyl. Bicyclic precursors lacking this ester group give mixtures of cis and trans products. Finally