Israel Fernández and José Luis Mascareñas review novel intramolecular (4 +3)-cycloaddition reactions of allenedienes in this Emerging Area article, focussing on recent examples where the allene acts as an allylic-cation surrogate. These methodologies overcome problems with previous strategies involving unstable allyl cation precursors or the need for stoichiometric activators and conformationally restricted dienes.
Areas covered include:
- (4 + 3)-Cycloaddition reactions mediated by platinum(II) and gold(I) complexes
- Aromaticity in the (4 + 3)-cycloaddition
- Concerted vs. stepwise reaction mechanisms
Transition metal-catalysed (4 + 3) cycloaddition reactions involving allyl cations
Israel Fernández and José Luis Mascareñas