Trivalent iodine

This trivalent iodine compound is obtained in about 90% yield by reaction of C H5I(OAc)2 with toluenesulfonic acid (2 equiv.) in CH,CN. ... 

Phenylbenzoic acid is converted into benzo[c]coumarin in the Su z system, that is irradiation when mixed with trivalent iodine compounds and iodine the 2-iodo derivative may also be formed <99JCS(P1)1713>. 

In recent years, tnflate derivatives of trivalent iodine have found more and more applications as versatile reagents m organic synthesis [135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145] p-Oxo-bis[(trifluoromethanesulfonyloxy) (phenyl)iodine], which is readily available from lodosobenzene and tnflic anhydride (equation 44), is especially valuable for the preparation of alkynyl lodomum tnflates from silyl- or stannylacetylenes [136 (equation 70)... 

The first two types, (a) and (b), called iodanes, are conventionally considered as derivatives of trivalent iodine I(+3). The next two, (c) and (d), periodanes, represent the most typical structural types of pentavalent iodine I(+5). The structural types (e) and (f) are typical of heptavalent iodine I(+7). 

Togo, H., Aoki, M., and Yokohama, M. (1993) Reductive addition to electron-deficient olefins with trivalent iodine compounds. Tetrahedron, 49, 8241-8256. 

Trivalent iodine compounds can be divided into the following categories (1) with one carbon-iodine bond, such as in iodo salts, RIX2, and iodoso compounds, RIO (2) with two carbon-iodine bonds on the same iodine, such as RRTX and (3) with three carbon-iodine bonds on the same iodine, such as Phsl. 

V-chloro-1,2,4-triazole 43 reacts with methyl iodide in the same manner. Formation of iodine and a mixture of /V-unsubstituted 1,2,4-triazoles, isomeric /V-alkyltriazoles, /V-iodotriazolcs, 1,4-dimethyltriazolium salts, and the products of their further transformations is observed (94ZOR1398 95ZOR113, 95ZOR1227). It is proposed that, similarly to N-halobenzotri-azoles, formation of an intermediate trivalent iodine compound and its subsequent cleavage to the reaction products takes place (Scheme 118). 

Basic and neutral salts are among the compounds containing positive trivalent iodine. The colorless neutral salts are extremely... 

Radical alkylation and carbamoylation of 4-cyanopyridine (54) have been reported. (54) has been alkylated with carboxylic acids, using trivalent iodine compounds as oxidant, to give (65) (Scheme 32) (93JCS(P1)2417>. (54)... 

A series of heterocyclic compounds containing trivalent iodine, oxygen and boron in a five-membered ring has been prepared by oxidative cyclization of commercially available orf/to-iodophenylboronic acids 182 and 185... 

A study of the catalytic a-acetoxylation reaction of acetophenone by electrospray ionization tandem mass spectrometry (ESI-MS/MS) has confirmed the mechanism shown in Scheme 4.2. In particular, the trivalent iodine species was detected when iodobenzene and mCPBA in acetic acid were mixed, which indicated the facile oxidation of a catalytic amount of Phi to the iodine(III) species by mCPBA. Most importantly, the protonated alkyliodonium intermediate 3 (R = Ph, = H) was observed at m/z 383 from the reaction solution and this ion gave the protonated a-acetoxylation product 1 at m/z 179 in MS/MS by an intramolecular reductive elimination of Phi [17]. 

In the first step of the mechanism, the enol form of acetophenone, acting as the nucleophile, attacks the trivalent iodine ... 

The mechanism is likely to involve nucleophilic attack by the enolate on the trivalent iodine center. Subsequent reductive elimination at iodine results in 2,2-diphenylindane-l,3-dione, the observed product, as shown below ... 

Recently, a well-known trivalent iodine reagent, DIB with low toxicity and high stability was used in the synthesis of substituted pyrroles. The multi-component reaction (MCR) of primary amines 28, nitrostyrenes 29 and acetylac-etone 27 was smoothly performed in the presence of DIB to form substituted pyrroles 30 in good yields. This facile and simple DIB-mediat MCR is applicable for the synthesis of biologically significant tolmetin 31 and related pyrroles (Scheme 2) [18]. 

In a similar approach, aromatic oximes 66 were oxidized to nitrile oxides 67 in tire presence of a mild trivalent iodine reagent, HTIB (Koser s reagent). Subsequently, the reactive 1,3-dipolar nitrile oxide 67 was treated with various alkynes 68 to afford trisubstituted isoxazoles 69 in good yields (Scheme 12) [28]. 

Similarly to the noncyclic trivalent iodine derivatives of strong acids, sulfonates 88—90 and 92—94 are highly reactive toward unsaturated organic substrates and other carbon nucleophiles, and have found practical application for the preparation of C-substituted benziodoxoles. 

The noncyclic CF3-substituted trivalent iodine derivatives lack stability and cannot be isolated at room temperature however, the incorporation of a hypervalent iodine atom into a five-membered heterocycle has a significant stabilization efiect. The synthesis of stable trifluoromethylbenziodoxoles 141 and 143—145 by treatment of the corresponding methoxybenziodoxole... 

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