Palladium(<scp>ii</scp>)-catalysed total synthesis of naturally occurring pyrano[3,2-<i>a</i>]carbazole and pyrano[2,3-<i>b</i>]carbazole alkaloids
作者:Ronny Hesse、Anne Jäger、Arndt W. Schmidt、Hans-Joachim Knölker
DOI:10.1039/c4ob00367e
日期:——
Seven naturallyoccurring pyranocarbazole alkaloids (pyrayafoline A–E, O-methylmurrayamine A and O-methylmahanine) have been obtained by totalsynthesis using a palladium(II)-catalysed oxidative cyclisation of a diarylamine to an orthogonally diprotected 2,7-dihydroxycarbazole as key step.
Seven new carbazole alkaloids, named pyraryafolines-B (1), -C (3), and -D (5), and euchrestines-A (7), -B (9), -C (10), and -D (11) were isolated from stem bark of Murraya euchrestifolia HAYATA (Rutaceae) collected in Taiwan and their sturctures were characterized by means of spectral methods. Pyrayafoline-B (1) was also synthesized.