MCR of Organoaluminium, Isoprene, Aldehydes and Amines

Significance

This is a nice extension on the previous three-component connection of organo­zincs, dienes and aldehydes (Y. Tamaru et al. Angew. Chem. Int. Ed. 1999, 38, 3386-3388). In this example the use of the often less electrophilic imine provides E-homoallylamines with very high selectivity (up to 20:1, E:Z). Electron-donating and -withdrawing substituents were tolerated in the aromatic aldehyde portion. The presence of Me₃Al was necessary for the methyl addition and Ph₂Zn was used for the phenyl addition.