RSS-Feed abonnieren
DOI: 10.1055/s-0030-1258548
Togni Reagent: A Hypervalent Iodine Based Electrophilic Trifluoromethylation Reagent
Publikationsverlauf
Publikationsdatum:
03. September 2010 (online)
![](https://www.thieme-connect.de/media/synlett/201016/lookinside/thumbnails/10.1055-s-0030-1258548-1.jpg)
Introduction
Antonio Togni and co-workers have [¹] reported a new electrophilic trifluoromethylating reagent based on a 10-I-3 hypervalent iodine, 3,3-dimethyl-1-(trifluoromethyl)-1,2-benziodoxole known as Togni reagent 1, which nicely complements the nucleophilic Ruppert-Prakash reagent. [²] The Togni reagent has the ability to transfer a CF3 moiety electophilically to a wide range of substrates and functionalities, including C=C and C-H bonds in hydrocarbons as well as atoms containing lone pairs, such as sulfide, primary and secondary alcohols. This electrophilic CF3 transfer agent is the reagent of choice for most trifluoromethylation reactions (better than Yagupol’skii, [³] Umemoto, [4-8] and Shreeve [9] reagents) due to its substrate-induced selectivity, specificity, high reactivity under mild conditions (at 0-25 ˚C and neutral pH), and applicability to acid- or base-sensitive substrates. It is easy to handle and can be exposed to moist air for short periods of time without any apparent alteration.
The Togni reagent is commercially available [CAS: 887144970] and can be easily prepared starting from iodobenzoic acid in a few-step synthesis. [¹]
Figure 1
- 1
Eisenberger P.Gischig S.Togni A. Chem. Eur. J. 2006, 12: 2579 - 2
Ruppert I.Schlich K.Volbach W. Tetrahedron Lett. 1984, 24: 2195 - 3
Yagupol"skii LM.Kondratenko NV.Timofeeva GN. J. Org. Chem.USSR (Engl. Transl.) 1984, 20: 103 - 4
Umemoto T.Ishihara S. Tetrahedron Lett. 1990, 31: 3579 - 5
Umemoto T.Ishihara S. J. Am. Chem. Soc. 1993, 115: 2156 - 6
Umemoto T.Adachi K. J. Org. Chem. 1994, 59: 5692 - 7
Umemoto T. Chem. Rev. 1996, 96: 1757 - 8
Umemoto T.Ishihara S. J. Fluorine Chem. 1998, 92: 181 - 9
Yang J.-J.Kirchmeier RL.Shreeve JM. J. Org. Chem. 1998, 63: 2656 - 10
Kieltsch I.Eisenberger P.Togni A. Angew. Chem. Int. Ed. 2007, 46: 754 - 11
Eisenberger P.Kieltsch I.Armanino N.Togni A. Chem. Commun. 2008, 1575 - 12
Stanek K.Koller R.Togni A. J. Org. Chem. 2008, 73: 7678 - 13
Koller R.Huchet Q.Battaglia P.Welch JM.Togni A. Chem. Commun. 2009, 5993 - 14
Koller R.Stanek K.Stolz D.Aardoom R.Niedermann K.Togni A. Angew. Chem. Int. Ed. 2009, 48: 4332