Transformations hydroxy iodo benzene

A reaction of considerable interest is the Hofmann type degradation of primary carboxamides to amines. Several examples have been reported of such efficient conversions, notably with the system IOB in formic acid (in water of acetonitrile), which forms in situ PhI(OOCH)2 [44], Other hypervalent iodine reagents have also been used extensively for these transformations (Sections 4.4.1 and 7.4.1). Yields may vary widely as illustrated for three similar amines obtained from the corresponding carboxamides with IOB-formic acid and with [hydroxy-(tosyloxy)iodo]benzene [45] ... 

Consider the following transformation of acetophenone with hydroxy(tosyloxy)iodo-benzene (HTIB), also known as Koser s reagent ... 

A related reagent to PhI(OAc)2 and PhI(02CCF3)2 is [hydroxy(tosyloxy)iodo]benzene (Phl(OH)OTs), which has the advantage over PhI(02CCp3)2 of improved stability and which is especially useful for the HR of long-chain primary amides." A similar HR reagent is [methoxy(tosyloxy)iodo]benzene (Phl(OMe)OTs), which has increased solubility in acetonitrile over that of PhI(OH)OTs." Examples of these HR transformations are given here (41 —> 42 and 43 —> 44 —> 45)." " Intermediate 44 could be isolated and characterized, and when it is heated in chloroform, the expected benzyl isocyanate is isolated." ... 

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