title: Lewis Acidity of Bis(perfluorocatecholato)silane: Aldehyde Hydrosilylation Catalyzed by a Neutral Silicon Compound.
abstract: Bis(perfluorocatecholato)silane Si(cat(F))2 was prepared, and stoichiometric binding to Lewis bases was demonstrated with fluoride, triethylphosphine oxide, and N,N'-diisopropylbenzamide. The potent Lewis acidity of Si(cat(F))2 was suggested from catalytic hydrosilylation and silylcyanation reactions with aldehydes. Mechanistic studies of hydrosilylation using an optically active silane substrate, R-(+)-methyl-(1-naphthyl)phenylsilane, proceeded with predominant stereochemical retention at silicon, consistent with a carbonyl activation pathway. The enantiospecificity was dependent on solvent and salt effects, with increasing solvent polarity or addition of NBu4BAr(F)4 leading to a diminished enantiomeric ratio. The medium effects are consistent with an ionic mechanism, wherein hydride transfer occurs prior to silicon-oxygen bond formation.
authors: Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States.|Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 United States.
authors: Allegra L
authors: AL
authors: Liberman-Martin
authors: Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States.|Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 United States.
authors: Robert G
authors: RG
authors: Bergman
authors: Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States.|Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 United States.
authors: T Don
authors: TD
authors: Tilley
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D002396:Catechols / Q000737:chemistry; D005466:Fluorocarbons / Q000737:chemistry*; D058116:Lewis Acids / Q000737:chemistry*; D008958:Models, Molecular; D012821:Silanes / Q000737:chemistry*; D017655:Silicon Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D002396:Catechols; D005466:Fluorocarbons; D058116:Lewis Acids; D012821:Silanes; D017655:Silicon Compounds