Rhenium Complexes as Highly Active Catalysts for the Hydrosilylation of Carbonyl Compounds

[Re(PiPr3)2(NO)2]+[B(C6F5)4]? (1) and the new NO-functionalized compounds [Re(H)(PiPr3)2(NO)(NOB(C6F5)3)] (2) and [Re(H)(NO)(NOEt)(PiPr3)2]+[B(C6F5)4]? (3) were prepared and found to be excellent catalysts for hydrosilylation of ketones. For 2 and 3 the hydrosilylation procedures are selective, mild, and efficient, and offer very practical methodologies to prepare the respective silyloxy compounds in quantitative yields. In exemplary experiments catalyst 2 could even be recovered.