Zwitterionic Relatives to the Classic [(P–P)Rh(solv)2]+ Ions: Neutral Catalysts Active for HE Bond Additions to Olefins (E=C, Si, B)

Formally zwitterionic bis(phosphanyl)- and bis(amino)borate rhodium(I) complexes (see picture) can catalytically mediate the hydrogenation, hydroacylation, hydroboration, and hydrosilation of double bonds. These neutral systems are shown to be highly active, even under conditions incompatible with their isostructural, but formally cationic, relatives.