Accetto Utilizziamo cookies per migliorare il nostro servizio e realizzare statistiche. Questa funzione puó essere disattivata cambiando la configurazione del browser. Continuando a navigare senza modificare questi parametri, consideriamo che l’uso di cookies sia accettato
Triethylsilane is used for the hydrosilation of olefins to prepare alkyl silanes. It acts as a reducing agent in the reduction of 2-chromanols, since it has an active hydride. It acts as a catalyst for redox initiated cationic polymerization, regioselective reductive coupling of enones and allenes, and Beckmann rearrangement of cyclododecanone oxime. It is associated with trifluoroacetic acid and involved in the selective reduction of alkenes.
In combination with TFA, "ionic hydrogenation" of alkenes occurs. This can be a useful alternative to catalytic hydrogenation, since selective reduction, e.g. of the more branched double bond of a diene can be achieved. For a review of ionic hydrogenation, see: Synthesis, 633 (1974):
For trans-hydrosilylation of alkynes, catalyzed by AlCl3, see: J. Org. Chem., 61, 7354 (1996); 64, 2494 (1999).
ɑß-Enones are reduced selectively to saturated ketones In the presence of TFA: Synthesis, 420 (1973); or Wilkinson's catalyst (Chlorotris(triphenylphosphine)rhodium(I), 10468): Tetrahedron Lett., 5035 (1972); Organometallics, 1, 1390 (1982).
With TFA, aliphatic ketones are reduced to secondary alcohols, whereas aromatic ketones and aldehydes are further reduced to the hydrocarbons: J. Org. Chem., 38, 2675 (1973). With BF3, both aliphatic and aromatic carbonyl groups are reduced to the hydrocarbons: J. Org. Chem., 43, 374 (1978); Synth. Commun., 24, 1999 (1994). For selective reduction of a ketone in the presence of a nitro group, see: Org. Synth. Coll., 7, 393 (1990). Reduction of ketones to methylenes also occurs in the presence of TICl4, allowing the formation of N-protected ɑ-amino acids from keto analogues without racemization: Heterocycles, 41, 17 (1995). For reduction of carbonyl groups catalyzed by B(C6F5)3, see: J. Am. Chem. Soc., 118, 9440 (1996). Reduction of aldehydes, acyl chlorides and esters to methyl groups using this catalyst has been described: J. Org. Chem., 66, 1672 (2001). The polysubstitution and rearrangement encountered with Friedel-Crafts alkylations can be circumvented by an effective one-pot technique employing AlCl3 acylation followed by in situ reduction with Et3SiH: J. Chem. Soc., Perkin 1, 1705 (1989). See also Poly(methylhydrosiloxane), L14561, as an alternative reducing agent.
For reductive alkylation of indoles, see 2-Methylindole, A10764.
Silylation of OH groups, with elimination of H2, occurs with catalysis by TBAF under very mild conditions: Tetrahedron Lett., 35, 8413 (1994); cf Chlorotriethylsilane, A15547. The use of 2-8 mol% Tris(pentafluorophenyl)borane, L18054, has been reported to be more effective than TBAF for the silylation of alcohols and phenols, with secondary and tertiary alcohols reacting faster than primary: J. Org. Chem., 64, 4887 (1999). With excess reagent, reduction of primary alcohols and ethers to methyl occurs: J. Org. Chem., 65, 6179 (2000).
High-yield, selective hydrodehalogenation of alkyl and aryl halides is catalyzed by PdCl2, avoiding the skeletal rearrangements of alkyl halides sometimes observed with Lewis acid catalysts such as AlCl3: Organometallics. 15, 1508 (1996); cf: J. Org. Chem., 41, 1393 (1976).
Using various Pt group catalysts, acyl halides can be reduced to aldehydes, as an alternative to the Rosenmund reduction. For examples, see: Org. Prep. Proced. Int., 12, 13 (1980). For reduction of nitriles to aldehydes, see: Triethyloxonium tetrafluoroborate, A14420. Nitroarenes can be reduced to anilines using Wilkinson's Catalyst: Synth. Commun., 26, 973 (1996).
In the presence of Ti(O-i-Pr)4, phosphine oxides can be reduced to phosphines, a useful alternative to pyrophoric HSiCl3: Tetrahedron Lett., 35, 625 (1994).
For use as a superior cation scavenger in peptide synthesis, see Triisopropylsilane, L09585.
Aryl halides have been silylated using PtO2 as a catalyst, to give aryltriethylsilanes: Org. Let.., 8, 931 (2006).
In combination with indium(III) chloride and a radical initiator, generates a radical reagent, analogous to Tri-n-butyltin hydride, A13298, which effects dehalogenation of alkyl halides to alkanes and radical addition of halides to alkenes, including dehalocyclizations: Org. Lett., 6, 4981 (2004).
Graham, T. H. Deprotection of N-benzylbenzimidazoles and N-benzylimidazoles with triethylsilane and Pd/C. Tetrahedron Lett. 2015, 56 (21), 2688-2690.
Ishikawa, H.; Kawasaki, T.; Inomata, R. Infrared Spectroscopy of Phenol- Triethylsilane Dihydrogen-Bonded Cluster and its Cationic Analogues: Intrinsic Strength of the Si-H··· H-O Dihydrogen Bond. J. Phys. Chem. A 2015, 119 (4), 601-609.
Dichiarazioni di rischio (UE): H225-H315-H319-H335
Highly flammable liquid and vapour. Causes skin irritation. Causes serious eye irritation. May cause respiratory irritation.
Dichiarazioni precauzionali: P210-P261-P303+P361+P353-P305+P351+P338-P405-P501a
Keep away from heat/sparks/open flames/hot surfaces. - No smoking. Avoid breathing dust/fume/gas/mist/vapours/spray. IF ON SKIN (or hair): Remove/Take off immediately all contaminated clothing. Rinse skin with water/shower. IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. Store locked up. Dispose of contents/container in accordance with local/regional/national/international regulations.