Construction of functionalized/substituted bipyridines by means of Negishi cross-coupling reactions. Formal synthesis of (±)-cytisine

Syntheses of (+)-Cytisine, (−)-Kuraramine, (−)-Isokuraramine, and (−)-Jussiaeiine A

Total syntheses of (+)-cytisine, (-)-kuraramine, (-)-isokuraramine, and (-)-jussiaeiine A were achieved via a samarium diiodide-promoted reductive deamination reaction, followed by simultaneous recyclization of a proline derivative to give the corresponding delta-lactam derivative, as a key step.

A short synthesis of (±)-cytisine

The synthesis of racemic cytisine has been completed using (i)N-selective alkylation of 6-bromopyridone with bromide and (ii) Pd(0) mediated intramolecular alpha-arylation of lactam as key steps to achieve rapid assembly of the tricyclic core skeleton of the lupin alkaloids.