Rhenium complexes as highly active catalysts for the hydrosilylation of carbonyl compounds

[Re((PPr3)-Pr-i)(2)(NO)(2)](+)[B(C6F5)(4)](-) (1) and the new NO-functionalized compounds [Re(H)((PPr3)-Pr-i)(2)(NO)(NOB (C6F5)(3))] (2) and [Re(H)(NO)(NOEt)((PPr3)-Pr-i)(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.