System HCOOH-sulfo cationite KU-1 as proton donor in ionic hydrogenation

Ionic and Organometallic‐Catalyzed Organosilane Reductions

“…217 The use of a sulfonated phenol-formaldehyde polymer in conjunction with formic acid is also reported. 208 Acids that are ineffective include phosphoric, 208 trichloroacetic, dichloroacetic, and acetic acids. 134 It is reported that addition of lithium perchlorate to the reaction mixture improves product yields.…”

“…134 It is reported that addition of lithium perchlorate to the reaction mixture improves product yields. 193,205 Other organosilane/acid reagent combinations that are used in the reduction of olefins to alkanes include Et 3 SiH/NH 4 F/TFA, 135 216 and Et 3 SiH/ HCO 2 H. 208 The triethylsilane/trifluoroacetic acid reagent system reduces alkenes to alkanes in poor to excellent yields depending largely on the ability of the alkene to form carbocations upon protonation. Under these conditions the more substituted olefins are reduced in better yields and styrene double bonds are reduced in high yields.…”

“…These reactions are usually accompanied by the formation of side products, which can include the alcohol, alkenes resulting from dehydration, ethers, and methylene compounds from over-reduction. 68,70,207,208,313,386 These mixtures may be converted into alcohol products if hydrolysis is employed as part of the reaction workup. An example is the reduction of cyclohexanone to cyclohexanol in 74% yield when treated with a two-fold excess of both trifluoroacetic acid and triethylsilane for 24 hours at Promotion by Valence Expansion.…”