Gold catalysed reactions of 3-dienyl-indoles (or 2-arylindoles with propargylic alcohols) afford terphenylamines, while indole-2-carboxylates give 3-indenylindoles under p-TsOH mediation.

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.

Dearomative ring expansion/spirocyclization of indole‐2‐carboxylates with propargylic alcohols bearing electron‐withdrawing aromatic groups in the presence of PTSA leading to spiro[benzo[b]oxazine‐furans] via oxygen insertion along with dihydrocyclopenta[e]indole‐2‐carboxylates is developed; the same reactants under moderately high temperatures, afford fused pyrano‐indolones. In contrast, copper(II) catalyzed annulation of indole‐2‐carboxylic acids with propargylic alcohols at room temperature provides rapid access to a different class of pentacyclic indene fused pyrano‐indolones.

Gold(I) Catalyzed Sequential Dehydrative Cyclization/Intermolecular [4 + 2] Cycloaddition of Alkynyldienols onto Activated Alkynes/Alkenes: A Facile Route to Substituted Norbornadienes/Norbornenes. -A new one-pot synthesis of highly substituted norbornadienes/norbornenes via gold-catalyzed dehydrative cyclization followed by intermolecular[4 + 2] cycloaddition of alkynyldienols and activated alkynes under mild conditions is described. -(URUVAKILI, A.; GANGADHARARAO, G.; KUMARA SWAMY*, K. C.; Org. Biomol. Chem. 13 (2015) 39, 10060-10071, http://dx.