Iodo group

Elimination.1 The dehydroiodination of y-iodo ketones or y-iodo esters with DBU at 25° to form cyclopropanes occurs readily only when the proton and the iodo group can adopt a W-shaped geometry. Thus the cyclopropane 1 is formed... 

Very good selectivity has also been achieved with iodinated imidazole derivatives, and thus the replacement of the 2-iodo group of 1-benzyloxy-methyT2,4,5-triiodoimidazole was achieved with n-BuLi in 99% yield (91JOC4296). 

For both the reactions there is no difference between the two transition states i.e., two states have the same energies scheme). Axial iodo group raises the energy of the starting material thus lowering the activation energy. 

P. J. Garegg and B. Samuelsson, Novel reagent system for converting a hydroxy-group into an iodo-group in carbohydrates with inversion of configuration, J. Chem. Soc. Chem. Common. p. 978 (1979). 

The large difference in reactivity between aryl iodides and bromides in the absence of phosphines allows the iodo group to be reacted in the presence of a bromo group in the same molecule. Subsequently the bromide may be reacted with another alkene if a phosphine is added.72 Aryl chloride groups are usually inert in the presence of bromo or iodo substituents. 

Substituted l-(2-mercaptophenyl)propyn-l-ones 519 are efficiently cyclized by IC1 under mild conditions to 2-substituted 3-iodothiochromones. The 3-iodo group allows further manipulation. There is no evidence for formation of a benzothiophenone by a 5-exo cyclization (Equation 180) <2006JOG1626>. 

A few conversions of iodo groups to iodoso and iodoxy functions have been reported 12s ... 

The particular versatility of an integrated iodopropyl group was recently demonstrated by Corriu and coworkers.189 In comparison with the chloropropyl group, they could show that the iodo group allows much easier and faster postsynthetic chemical... 

Cyclization of 152 with hydrogen iodide in acetic acid is more complicated and proceeds with concomitant reduction (of the iodo group) and acetylation, the final product being 154. With this reagent some... 

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