Stereoselectivity of the benzannulation reaction: efficient central-to-axial chirality transfer.
High diastereoselectivity is observed in the preparation of configurationally stable allocolchicinoids 5 from Fischer carbene complexes 4 and 1-pentyne. The analogous reaction of complexes 8 gives 9 with moderate diastereoselectivity for the opposite atropisomer and this selectivity can be taken to high levels under thermodynamic conditions.
Vorogushin
Andrei V
AV
Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA.
Wulff
William D
WD
Hansen
Hans-Jürgen
HJ
D003078:Colchicine / Q000031:analogs & derivatives* / Q000138:chemical synthesis*; D013237:Stereoisomerism; D013379:Substrate Specificity
C032782:allocolchicine; D003078:Colchicine