<strong>Branched selective hydroformylation:  A useful tool for organic synthesis</strong>

Hydroformylation reactions that show branched regioselectivity are reviewed. The mechanism of hydroformylation and the current state of the art in linear selective hydroformylation is briefly discussed prior to a more in depth discussion on synthetically useful branched selective hydroformylation reactions. The review divides these into several different classes; hydroformylation of internal cyclic alkenes, acyclic internal alkenes, aryl alkenes, terminal alkenes bearing electron withdrawing groups, terminal alkenes bearing groups that can potentially co-ordinate to the rhodium catalysts, and simple terminal alkenes. Recent advances in asymmetric hydroformylation are also discussed. The review aims to provide the non-specialist and expert reader with the information required to assess the type of substrate, catalyst and reaction conditions that are likely to be conducive to obtaining branched aldehydes in a hydroformylation reaction.