Using organohypervalent iodine reagents

Synthesis of Heterocyclic Compounds Using Organohypervalent Iodine Reagents... 

Moriarty, R. M., Prakash, O., Synthesis of Heterocyclic Compounds Using Organohypervalent Iodine Reagents, 69, 1. 

Moriarty, R.M. and Prakash, O., Synthesis of heterocychc compounds using organohypervalent iodine reagents, Adv. Heterocyclic Chem., 69,1, 1998. 

Several organohypervalent iodine reagents have been used for the oxidation of alcohols and phenols such as iodoxybenzene, o-iodoxybenzoic acid (IBX), bis(trifluoroa-cetoxy)iodobenzene (BTI), and Dess-Martin periodinane etc. But the use of inexpensive iodobenzene diacetate (IBD) as an oxidant, however, has not been fully exploited. Most of these reactions are conducted in high boiling DMSO or toxic acetonitrile media that results in increased burden on the environment. 

Syntheses of heterocyclic compounds that are dealt with in this review are achieved either by cyclization of open-chain substrates under the action of organohypervalent iodine reagents or by carrying out several sequential transformations of substrate heterocyclic compounds using these reagents to obtain new heterocyclic derivatives. In this section, we cover the first strategy, leaving the second one for Section III. An area that is not covered... 

Besides iodonium ylides, alkynyliodonium salts are also useful in heterocyclic synthesis. These salts are obtained from the reaction of the alkynes with an appropriate organohypervalent iodine reagent (Scheme... 

Volume 69 of Advances in Heterocyclic Chemistry consists of six contributions. The opening chapter, by Professor R. M. Moriarty and Dr. O. M. Prakash of the University of Illinois at Chicago, summarizes the use of organohypervalent iodine reagents in the synthesis of organic compounds, a subject of increasing importance and one for which no general review has as yet appeared. 

Organohypervalent iodine reagents such as iodoxybenzene, o-iodoxybenzoic acid (IBX), bis(trifluoroacetoxy)iodobenzene (BTI), and Dess-Marhn periodinane have been used for the oxidation of alcohols and phenols. Most of these reactions are conducted in high-boiling DMSO or relahvely toxic acetonitrile, which increase the burden on the environment. Further, the use of inexpensive iodobenzene diacetate (IBD) as an oxidant has not been fully exploited. Varma et al. have reported the first use of supported iodobenzene diacetate as an oxidant. In this novel oxidative protocol, alumina-supported IBD under solvent-free conditions rapidly converts alcohols to the corresponding carbonyl compounds in almost quantitative yields. The use of alumina as a support improved the yields markedly as compared to neat IBD (Scheme 2.2-40). 1,2-Benzenedimethanol, however, undergoes cyclization to afford l(3H)-isobenzofuranone [116]... 

Organohypervalent iodine(in) compounds are particularly usefiil as the oxidants in the Hofmann-type degradation of aliphatic or aromatic carboxamides to the respective amines [483]. The most common reagents for Hofmann-type rearrangements include (diacetoxyiodo)benzene [484-488], [bis(trifluoroacetoxy)-iodo]benzene [489-494], [hydroxy(tosyloxy)]iodobenzene [495-499] and their recyclable analogs (Chapter 5). The catalytic version of the Hofmann rearrangement using aryl iodides and m-chloroperoxybenzoic acid as terminal oxidant has also been reported (Section 4.1). 

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