Umpolung of hemiaminals: Titanocene-catalyzed dehydroxylative radical coupling reactions with activated alkenes
Radical measures: A radical coupling reaction, which is proposed to proceed through in situ chlorination of a hydroxy group by Me3SiCl, is used to form quaternary carbon centers with amino groups in α position. The reaction can be scaled up and
Diastereoselective Synthesis of Cis-3- And 3,5-Alkylpyrrolizidines
Cis-3 and 3,5-substituted pyrrolizidines can be prepared from β-enaminolactones. Substituted pyrrolidinoketones lead to these compounds by an amino reductive annelation with a low diastereomeric excess, but a best access to these azabicycles consists in preparing cis-2,5-disubstituted pyrrolidines which are then transformed into the expected heterocycles.