Three-component bimetallic (Pd/In) mediated cascade allylation of C=X functionality: Part 1. Scope and Class 1 examples with aldehydes and ketones

A new general three-component Pd/In bimetallic cascade reaction with four synthetic variants involving aryl iodides, allenes and C=X compounds affording homoallylic alcohols/amines as products is described and exemplified for Class 1 processes (intermolecular Pd–intermolecular In steps). Remarkable increases in yield and reaction rates were observed in the presence of amine additives. Excellent diastereoselection is exhibited when 2-hydroxycyclohexanone is employed, and semi-empirical and ab initio calculations are used to rationalise the observed syn:anti diastereoselectivity.