Gold(I) catalysed sequential dehydrative cyclisation/intermolecular [4 + 2] cycloaddition of alkynyldienols onto activated alkynes/alkenes: a facile route to substituted norbornadienes/norbornenes.
One-pot synthesis of highly substituted norbornadienes/norbornenes via gold-catalysed dehydrative cyclisation of alkynyldienols, followed by intermolecular [4 + 2] cycloaddition of in situ generated cyclopentadiene and activated alkynes/alkenes is described. The precursors, alkynyldienols, are obtained via sequential Sonogashira cross-coupling of 3-bromoenals, alkyne addition and reduction. Yields of the enynals and multisubstituted norbornadienes in all the cases are good to excellent.
School of Chemistry, University of Hyderabad, Hyderabad-500046, Telangana, India. kckssc@uohyd.ac.in kckssc@yahoo.com.
Anasuyamma
A
Uruvakili
G
G
Gangadhararao
K C
KC
Kumara Swamy