Organohypervalent Iodine:  Development, Applications, and Future Directions

Moriarty, Robert M.

doi:10.1021/jo050117b

Cited by 414 publications

(108 citation statements)

References 118 publications

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“…Slower reaction was observed using 0.1 eq of 4-iodoanisole (entry 13). However, larger amounts (0.5-1 eq) led to decreased reaction times with similar yields of 3a (entries 14,15).…”

Section: Resultsmentioning

confidence: 97%

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Catalytic Hypervalent Iodine Oxidation Using 4-Iodophenoxyacetic Acid and Oxone: Oxidation of p-Alkoxyphenols to p-Benzoquinones

Yakura

Tian

Yamauchi

et al. 2009

CHEMICAL & PHARMACEUTICAL BULLETIN

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Hypervalent iodine compounds, trivalent iodine compounds such as phenyliodine(III) diacetate (PIDA) and phenyliodine(III) trifluoroacetate (PIFA) and pentavalent iodine reagents such as Dess-Martin periodinane (DMP) and o-iodoxybenzoic acid (IBX), have been used extensively in recent organic synthesis because of their low toxicity, ready availability and easy handling. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] However, these reagents are highly expensive. And stoichiometric amounts of iodine reagents are required to produce equimolar amounts of organic iodine waste. Moreover, pentavalent iodine reagents are potentially explosive. To overcome these disadvantages, catalytic hypervalent iodine oxidations [16][17][18] using mchloroperbenzoic acid (m-CPBA), [19][20][21][22][23][24][25][26][27] Oxone ® (2KHSO 5 · KHSO 4 · K 2 SO 4 ), 28,29) and H 2 O 2 30) as a co-oxidant have been reported recently.Development of efficient methods for synthesis of pquinone and p-quinone derivatives is an important subject in synthetic organic chemistry because they are structural components of numerous natural products and useful synthetic intermediates. [31][32][33][34][35][36] A convenient procedure for p-quinones was hypervalent iodine oxidation of p-alkoxyphenols using PIFA.37) Reactions of p-alkoxyphenols with an equimolar amount of PIFA in a 2 : 1 mixture of acetonitrile and water at room temperature gave the corresponding p-quinones in excellent yield.As part of our study for development of practical and environmentally benign oxidation, we report a mild, efficient and practical procedure for catalytic hypervalent iodine oxidation of p-alkoxyphenols to p-quinones using a catalytic amount of 4-iodophenoxyacetic acid (1a) and Oxone ® as a co-oxidant 38) in 2,2,2-trifluoroethanol-water. Results and DiscussionWe chose Oxone ® as an environmentally safe co-oxidant for a catalytic hypervalent iodine oxidation of p-alkoxyphenols because Oxone ® is an inorganic and water-soluble oxidant with a low order of toxicity, moreover, it is commercially available and inexpensive. 39) Oxone ® has been already used as a co-oxidant under heating conditions in the catalytic IBX oxidation by Vinod 28) and Giannis 29) groups, independently. Because alkoxyphenols have high reactivity under oxidation conditions, we first investigated the oxidative ability of Oxone ® itself. 40) A mixture of 2-pivaloyloxymethyl-4-methoxyphenol (2a) and an equimolar amount of Oxone ® in acetonitrile-water (2 : 1) at room temperature gave the corresponding p-benzoquinone (3a), but the reaction was sluggish and the yield of 3a was only 13% along with 78% of recovered starting 2a after 24 h. Next, we examined reactions of 2a in the presence of several iodoarenes as a catalyst (Chart 1). Table 1 presents the results. According to the procedure reported by Vinod, 28) a mixture of 2a, 0.2 equivalents (eq) of 2-iodobenzoic acid, and 1 eq of Oxone ® in acetonitrile-water was heated at 70°C for 19 h to give a complicated mixture (entry 2). However, a similar reactio...

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“…Slower reaction was observed using 0.1 eq of 4-iodoanisole (entry 13). However, larger amounts (0.5-1 eq) led to decreased reaction times with similar yields of 3a (entries 14,15).…”

Section: Resultsmentioning

confidence: 97%

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] However, these reagents are highly expensive. And stoichiometric amounts of iodine reagents are required to produce equimolar amounts of organic iodine waste.…”

mentioning

confidence: 99%

Catalytic Hypervalent Iodine Oxidation Using 4-Iodophenoxyacetic Acid and Oxone: Oxidation of p-Alkoxyphenols to p-Benzoquinones

Yakura

Tian

Yamauchi

et al. 2009

CHEMICAL & PHARMACEUTICAL BULLETIN

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“…For a more comprehensive discussion of the numerous significant contributions made to this field by Moriarty's group, including α-hydroxylation of acetals, which falls outside the scope of this article, the 2005 review article is referred to. [56] Polymer-supported hypervalent iodine reagents have also found application in the α-hydroxylation of ketones. Togo et al reported a method similar to Moriarty's PIDA-mediated hydroxylation reaction using poly[4-(diacetoxyiodo)styrene] under basic conditions.…”

Section: Hydroxylationmentioning

confidence: 99%

“…The butane-1,4-dione products were formed in moderate yields. [56,136] The groups of Caple and Zefirov later developed iodosobenzene tetrafluoroborate and iodosobenzene hexafluorophosphate as stable and superior reagents for the homocoupling of TMS enol ethers (Scheme 70). [137] These reagents were also efficient in the coupling of aliphatic substrates.…”

Section: Homocouplingmentioning

confidence: 99%

α-Functionalization of Carbonyl Compounds Using Hypervalent Iodine Reagents

Merritt¹,

Olofsson²

2010

Synthesis

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“…Thus, alternative methods for this transformation are desirable. Organohypervalent iodine reagents [10][11][12][13][14][15][16][17][18][19] have been increasingly used in contemporary organic synthesis. In particular, organoiodine(III) reagents, namely (diacetoxyiodo)benzene, 20 bis(trifluoroacetoxy)iodobenzene, 21 [hydroxy(tosyloxy)iodobenzene] 22 and iodosobenzene (IOB) 23 have emerged as versatile oxidizing agents.…”

Section: Introductionmentioning

confidence: 99%