Indium triflate

Indium triflate
Names
	IUPAC name indium(3+);tris(trifluoromethanesulfonate)
	Other names Indium(III) trifluoromethanesulfonate; In(OTf)3; In(TFA)3; Indium(III) triflate; Trifluoromethanesulfonic acid indium(III) salt; Tris(trifluoromethanesulfonato)indium;
Identifiers
CAS Number	128008-30-0 ;
3D model (JSmol)	Interactive image; Interactive image;
ChemSpider	2016424;
ECHA InfoCard	100.157.173
EC Number	628-947-0;
PubChem CID	16687927; 2734680;
CompTox Dashboard (EPA)	DTXCID50321479;
	InChI InChI=1S/3CHF3O3S.In/c32-1(3,4)8(5,6)7;/h3(H,5,6,7);/q;;;+3/p-3 Key: UCYRAEIHXSVXPV-UHFFFAOYSA-K;
	SMILES C(F)(F)(F)S(=O)(=O)O[In](OS(=O)(=O)C(F)(F)F)OS(=O)(=O)C(F)(F)F; [In+3].[O-]S(=O)(=O)C(F)(F)F.[O-]S(=O)(=O)C(F)(F)F.[O-]S(=O)(=O)C(F)(F)F;
Properties
Chemical formula	C3F9InO9S3
Molar mass	562.01 g·mol−1
Appearance	solid
Density	1.7 g/cm3
Solubility in water	soluble
Hazards
	GHS labelling:
Pictograms
Hazard statements	H315, H319, H335
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Indium triflate is a complex inorganic compound of indium, fluorine, carbon, sulphur, and oxygen with the chemical formula (CF₃SO₃)₃In.^[1] This is the indium salt of trifluoromethanesulphonic acid. As a water-stable Lewis acid, the compound is a practical catalyst and finds wide application in organic synthesis.^[2]^[3]

Physical properties

The compound forms a white, powdery solid. It is a Lewis acid, but unlike most other such compounds, it is not very sensitive to hydrolysis and is stable in aqueous solution.^[4]

It is soluble in organic solvents like acetonitrile and dichloromethane, but often reported as sparingly soluble in hydrocarbons.^[5]

Synthesis

Indium triflate is typically synthesized by reacting indium(III) oxide with trifluoromethanesulfonic acid in water:

In₂O₃ + 6HOTf → 2In(OTf)₃ + 3H₂O

The compound is then isolated by filtering off excess oxide and evaporating the water.^[6]

Uses

The compound serves as a catalyst and in synthesis of stable indium bacteriochlorins.^[7]

References

^ "Indium Triflate". American Elements. Retrieved 12 May 2026.
^ "Indium(III) trifluoromethanesulfonate". Sigma Aldrich. Retrieved 12 May 2026.
^ Jamshaid, Sana (13 May 2024). "Indium Triflate's Transformative Role in Modern Organic Synthesis: A Five-Year Survey of Functionalization, Cyclization, and Multicomponent Reactions". ChemistrySelect. 9 (18) e202400313. doi:10.1002/slct.202400313. ISSN 2365-6549. Retrieved 12 May 2026.
^ Ghosh, Rina; Maiti, Swarupananda (March 2007). "Advances in indium triflate catalyzed organic syntheses". Journal of Molecular Catalysis A: Chemical. 264 (1–2): 1–8. doi:10.1016/j.molcata.2006.08.086. Retrieved 12 May 2026.
^ Frost, Christopher G. (2004). "Indium(III) Triflate". Encyclopedia of Reagents for Organic Synthesis. John Wiley & Sons, Ltd. doi:10.1002/047084289X.rn00397. ISBN 0-471-93623-5. Retrieved 12 May 2026.
^ Thakur, Ashim Jyoti (2003). "Tris(trifluoromethanesulfonato)indium". Synlett (6): 0899–0900. doi:10.1055/s-2003-38759.
^ Gregg, Brian T.; Golden, Kathryn C.; Quinn, John F. (1 July 2007). "Indium(III) Trifluoromethanesulfonate as an Efficient Catalyst for the Deprotection of Acetals and Ketals". The Journal of Organic Chemistry. 72 (15): 5890–5893. doi:10.1021/jo0707075. ISSN 0022-3263. PMID 17595139. Retrieved 12 May 2026.

[1] "Indium Triflate". American Elements. Retrieved 12 May 2026.

[2] "Indium(III) trifluoromethanesulfonate". Sigma Aldrich. Retrieved 12 May 2026.

[3] Jamshaid, Sana (13 May 2024). "Indium Triflate's Transformative Role in Modern Organic Synthesis: A Five-Year Survey of Functionalization, Cyclization, and Multicomponent Reactions". ChemistrySelect. 9 (18) e202400313. doi:10.1002/slct.202400313. ISSN 2365-6549. Retrieved 12 May 2026.

[4] Ghosh, Rina; Maiti, Swarupananda (March 2007). "Advances in indium triflate catalyzed organic syntheses". Journal of Molecular Catalysis A: Chemical. 264 (1–2): 1–8. doi:10.1016/j.molcata.2006.08.086. Retrieved 12 May 2026.

[5] Frost, Christopher G. (2004). "Indium(III) Triflate". Encyclopedia of Reagents for Organic Synthesis. John Wiley & Sons, Ltd. doi:10.1002/047084289X.rn00397. ISBN 0-471-93623-5. Retrieved 12 May 2026.

[6] Thakur, Ashim Jyoti (2003). "Tris(trifluoromethanesulfonato)indium". Synlett (6): 0899–0900. doi:10.1055/s-2003-38759.

[7] Gregg, Brian T.; Golden, Kathryn C.; Quinn, John F. (1 July 2007). "Indium(III) Trifluoromethanesulfonate as an Efficient Catalyst for the Deprotection of Acetals and Ketals". The Journal of Organic Chemistry. 72 (15): 5890–5893. doi:10.1021/jo0707075. ISSN 0022-3263. PMID 17595139. Retrieved 12 May 2026.

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