Asymmetric Hydrogenation of Farnesol and O-Protected Derivatives

Significance

The asymmetric hydrogenation of olefins is a useful reaction for the synthesis of optically active compounds. However, the utility of rhodium or ruthenium diphosphine catalysts is usually limited to substrates containing a coordinating group or an aryl substituent next to the double bond. The authors report a class of chiral iridium catalysts bearing pyridylphosphine ligands which do not require any coordinating group broadening the scope of the asymmetric hydrogenation. Internal trialkyl-substituted olefins and allylic alcohols are efficiently hydrogenated with facial selectivity. Different isomers of the substrate are efficiently converted into the corresponding stereoisomeric products in excellent enantio­selectivities and yields.