Abstract
Stereoselective and diversity‐oriented synthesis of trisubstituted olefins was achieved by using ortho‐diphenylphosphanyl benzoate (o‐DPPB) as a directing group for allylic substitution. The starting point of this methodology was a set of α‐methylene aldehydes derived from Baylis–Hillman adducts. Subsequent addition of different organometallic reagents led to a variety of allylic alcohol substrates. After introduction of the reagent‐directing o‐DPPB group, copper‐mediated allylic substitution with a wide range of Grignard reagents enabled the stereoselective construction of a large number of E‐configured trisubstituted allylic alcohols and amines in excellent yields and stereoselectivities. Remarkable is the synthetic flexibility, which allows a wide range of permutations starting from an aldehyde followed by successive introduction of the substituents R^2^ and R^3^ from organometallic Grignard based reagents. Thus, starting from only a few precursors, a diversity‐oriented synthesis of stereodefined trisubstituted allylic alcohols and amines becomes possible.