Zd. Jin et Pl. Fuchs, PALLADIUM[O]-MEDIATED AMINOSPIROCYCLIZATION OF TERTIARY ALLYLIC SULFONES - STEREOSPECIFIC CONSTRUCTION OF THE AZABICYCLIC RING-SYSTEM OF CEPHALOTAXINE, Tetrahedron letters, 37(30), 1996, pp. 5253-5256
Tertiary allylic sulfones which bear a secondary aminopropyl moiety un
dergo smooth palladium [0]-mediated spirocyclization. The reaction pro
ceeds via a pi-allyl intermediate and the resultant azabicyclic produc
t is formed with net retention of sulfone stereochemistry. The use of
tetramethylguanidine as companion base is required For high yielding r
eactions. Copyright (C) 1996 Elsevier Science Ltd