195529 Sigma-Aldrich



Synonym: TMIS, Trimethyliodosilane

  • CAS Number 16029-98-4

  • Linear Formula (CH3)3SiI

  • Molecular Weight 200.09

  •  Beilstein/REAXYS Number 1731136

  •  EC Number 240-171-0

  •  MDL number MFCD00001028

  •  PubChem Substance ID 24851696

  •  NACRES NA.22



Related Categories Chemical Synthesis, Chemicals for the synthesis of candidate COVID-19 treatments, Cobicistat, Protecting and Derivatizing Reagents, Protection and Derivatization,
Quality Level   200
assay   97%
contains   copper as stabilizer
refractive index   n20/D 1.471 (lit.)
bp   106 °C (lit.)
density   1.406 g/mL at 25 °C (lit.)
storage temp.   −20°C
SMILES string   C[Si](C)(C)I
InChI   1S/C3H9ISi/c1-5(2,3)4/h1-3H3


General description

Iodotrimethylsilane is a multipurpose reagent used in various organic reactions. It is used for the dealkylation of few compounds like lactones, ethers, acetals, and carbamates and trimethylsilylating agent for the synthesis of silyl imino esters, alkyl and alkenyl silanes, etc. It also acts as a Lewis acid catalyst and as a reducing agent in many organic reactions.


5, 25, 100 g in ampule


Efficient reagent for cleaving ethers, esters, carbamates, ketals, and lactones.

For the introduction of the TMS group, e.g., TMS enol ethers. Key reagent for the selective deprotection of an N-Cbz group in the presence of a trimethyltin moiety.

Reagent was recently reported to convert allyl- and benzylphosphotriesters to the corresponding iodides.

Safety & Documentation

Safety Information

Signal word 
Hazard statements 
Precautionary statements 
Supplemental Hazard Statements 
UN 2924 8(3) / PGII
WGK Germany 
Flash Point(F) 
-23.8 °F - closed cup
Flash Point(C) 
-31 °C - closed cup


Certificate of Analysis (COA)

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Certificate of Origin (COO)

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Frequently Asked Questions

Which document(s) contains shelf-life or expiration date information for a given product?
If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis.
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The lot specific COA document can be found by entering the lot number above under the "Documents" section.
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What is the Department of Transportation shipping information for this product?
Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product.
What is known of the mechanism of reactions involving product 195529, Iodotrimethylsilane?
The mechanism for cleavage of esters is described in PNAS, 75(1), 4-6 (1978).The authors go on to explain that the data do not support a previously published mechanism via a carbenium iodide.The paper also discusses the cleavage of ethers using iodotrimethylsilane. It appears that this is not as efficient as cleavage of esters, and a couple of mechanisms (pages 5 and 6) are proposed.Olah also described the cleavage of the phosphate esters in peptides that contain phosphate esters, using iodotrimethylsilane (Tetrahedron, 38, 2225 (1982)). The amide linkages in the peptide backbone are not cleaved.
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Protocols & Articles


Activating Reagents and Protecting Groups

The use of activating agents and protecting groups in organic synthesis is necessary to prevent unwanted side reactions from occurring when using other common reagents such as oxidizing or reducing a...
Chemfiles Volume 1 Article 3
Keywords: Organic synthesis

Peer-Reviewed Papers


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