Acylsilane

Summary

Acylsilanes are a group of chemical compounds sharing a common functional group with the general structure RC(O)-SiR3.[1]

The general structure of an acylsilane

Synthesis edit

Acylsilanes can be synthesized by treating acyl anion equivalents with silyl halides (typically trimethylsilyl chloride, tmsCl). Silylation of 2-lithio-1,3-dithiane, followed by hydrolysis of the dithioacetal group with mercury(II) chloride.[2] Analogous methods has also been used to produce acylgermanes.

 
Brook acylsilane synthesis scheme.

Several approches to acylsilanes start with carboxylic acid derivatives.[1] Esters undergo reductive silylation en route to acylsilanes:

RCO2Me + 2 tmsCl + Mg → RC(OMe)(Otms)(tms) + MgCl2
RC(OMe)(Otms(tms) + → RC(O)tms + MeOtms

Tertiary amides react with silyl lithium reagents:

RCONR'2 + Litms → RC(O)tms + LiNR'2

Acid chlorides are converted using hexamethyldisilane:

RCOCl + tms−tms → RC(O)tms + tmsCl

Some acyl silanes are prepared by oxidation of a suitable silanes.[1]

 
Kuwajima acylsilane synthesis, with the method to make the 1,1-bis(trimethylsilyl)alkan-1-ol.[3]

Reactions edit

Acylsilanes are starting compounds in the Brook rearrangement with vinyl lithium compounds to silyl enol ethers.

Acyl silanes and aryl bromides are coupling partners in Pd-catalyzed cross coupling reactions:[4]

Further reading edit

  • The reactivity of α- and β-iodo propenoylsilanes: an alternative access to polyunsaturated acylsilanes Alessandro Degl’Innocenti, Antonella Capperucci, Patrizia Scafato, Antonella Telesca Arkivoc 0-005A 2000 Article

References edit

  1. ^ a b c Zhang, Hui-Jun; Priebbenow, Daniel L.; Bolm, Carsten (2013). "Acylsilanes: Valuable Organosilicon Reagents in Organic Synthesis". Chemical Society Reviews. 42 (21): 8540–8571. doi:10.1039/c3cs60185d. PMID 23942548.
  2. ^ Brook, A. G. (Jan 1, 1967). "Synthesis of Silyl and Germyl Ketones". Journal of the American Chemical Society. 89 (2): 431–434. doi:10.1021/ja00978a047.
  3. ^ *Kuwajima, Isao; Abe, Toru; Minami, Naoki (1976-09-05). "An Efficient Method for the Preparation of Acylsilane and α-haloacylsilane". Chemistry Letters. 5 (9): 993–994. doi:10.1246/cl.1976.993. ISSN 0366-7022.
  4. ^ Mehta, Milauni M.; Kelleghan, Andrew V.; Garg, Neil K. (2021). "Palladium-Catalyzed Acetylation of Arylbromides". Organic Syntheses. 98: 68–83. doi:10.15227/orgsyn.098.0068.