A new ferrocenyl bisphosphorus ligand for the asymmetric hydrogenation of α-methylene-γ-keto-carboxylic acidsElectronic supplementary information (ESI) available. See DOI: 10.1039/c7cc04401a

Upon incorporation of a noncovalent ion pair interaction, a new chiral ferrocenyl bisphosphorus ligand t -Bu-Wudaphos was developed. t -Bu-Wudaphos can be easily synthesized with very high diastereoselectivity as a highly air stable solid. The new ligand exhibited excellent reactivities and enantioselectivities in the asymmetric hydrogenation of α-methylene-γ-keto-carboxylic acids via an ion pair noncovalent interaction (up to >99% conversion, >99% ee). A new chiral ferrocenyl bisphosphorus ligand t -Bu-Wudaphos exhibited excellent performance in the asymmetric hydrogenation of α-methylene-γ-keto-carboxylic acids (up to >99% conversion, >99% ee).