Chirality Transfer in Acyclic Allylic Systems and New Pd-Catalyzed Heck Reaction/C-H Activation Cascades

In the first part, the use of chirality transfer in acyclic allylic
systems was assessed for an intra- and an intermolecular reaction.
The thermal [2,3] sigmatropic rearrangement of acyclic allylic
phosphinites proved to be highly enantioselective, even at 110 °C
and led to enantiomerically pure allylic phosphine oxides. The
substitution pattern of the substrate and the reaction conditions
were fully optimized.The chirality transfer concept was also used
intermolecularly in asymmetric allylic substitution reactions. This
allowed to build up enantiomerically pure quaternary centers. The
product were then reacted to obtain enantionerically pure tertiary
alcohols, desymmetrized 1,3 diols and aldol compounds. In a second
part, it was found that Heck reaction leading to neopentylic
palladium species underwent, in the absence of nucleophile, a C-H
activation reaction, leading to spiro cyclopropyl compounds.