Libr is an efficient catalyst for the dihydroxylation of alkenes to afford either syn or anti diols with excellent diastereoselectivity depending upon the use of naio 4 or phioac 2 as the oxidants. Hypervalent iodinetempomediated oxidation in flow systems. Hypervalent iodine reagents for heterocycle synthesis and. Stoichiometric hypervalent iodine reagents the synthesis of difluoromethylcontaining compounds via reaction of styrene derivatives with fluorinated hypervalent iodine reagents or iodine in the presence xef2 150156 is also a known method. Herein, we describe the development of continuousflow systems using hypervalent iodine reagents in the tempomediated oxidation of alcohols with the advantage of significantly shortened reaction times. Appl phio2mediated oxidation of benzyl alcohols to the. However, treatment of cyclic olefins with iodine iii. Without modifier, iodane is the systematic name for the parent hydride of iodine, hi.
Ibxtfoh mediated oxidation of primary and secondary alcohols to carbonyls is reported. With additional optimization of the reaction conditions, the method appears extendable to other nucleophiles such as. The oxidation of cycloalkenes with hypervalent iodine has been reported by several authors. An aqueous phase tempomediated electrooxidation of benzyl. The journal of organic chemistry 1997, 62 20, 69746977. A visiblelightinduced oxidation of alcohols generates alkoxyl radicals mediated by iodine iii reagents under mild reaction conditions. A selective and efficient method for alcohol oxidations. This transformation involves trapping reactive sulfonium species using alcohols. The developed synthetic protocol can be used for the oxidation of alcohols at 1 g scale. Carbonyl oxidation with hypervalent iodine reagents wikipedia. This dissertation investigates and describes the hypervalent iodine mediated dearomatization of naphthols, thereby yielding diversity of spiroheterocyclic compounds in both racemic and chiral form. Hypervalent iodineiiimediated decarboxylative rittertype.
Iodineiiimediated halogenations of acyclic monoterpenoids. These protocols include catalytic imidations with iodonium imides, hypervalent iodine mediated oxidative coupling of phenols and related compounds, applications of iodine iii compounds as useful carbene and nitrene precursors and the broad synthetic applications of hypervalent iodine heterocycles derived from benziodoxoles and benziodazoles. Can oxidize allylic alcohols to enals with ibx and do wittigs in one pot yadav, synth. This protocol describes a practical laboratoryscale method for aerobic oxidation of primary alcohols to aldehydes, using a chemoselective cuitempo tempo 2,2,6,6tetramethyl1. Page 63 1 this methodology was extended to ctab reversed micelle mediated oxidation of sulfides in a variety of nonpolar solvents such as toluene and nhexane, which have not been used as the solvents in hypervalent iodine oxidation, in the presence of a small amount of water to afford the corresponding sulfoxides in excellent yields. Hypervalent iodinemediated synthesis of spiroheterocycles via oxidative cyclization volume.
By utilizing a specific solvent and highly active 2azaadamantanenoxyl azado as an organocatalyst, we have improved the recycling protocol of the adamatane reagent 1 to be faster and more operationally simple for the hypervalent iodinenitroxyl radical mediated alcohol oxidation. We have developed the first example of hypervalent iodinevcatalyzed regioselective oxidation of phenols to oquinones. Request pdf hypervalent iodinemediated oxidation of alcohols over the past two decades there has been a dramatic increse in the use of hypervalent iodine compounds in synthetic organic. Request pdf on aug 11, 2009, muhammet uyanik and others published cheminform abstract. Synthesis of hypervalent iodine compounds for oxidation reactions 221 viktor v. A green and facile electrocatalytic method for the oxidation of benzyl alcohol in an acidic aqueous medium was developed using an anionic micellar system. Hypervalent iodinemediated oxidation of alcohols chemical. This method possesses a wide range of capabilities since it can be used with other functional groups which may not tolerate oxidative conditions. Iodosobenzene diacetate, phenyliodonium diacetate, pida. A highly efficient tempo mediated oxidation of sugar.
Zhdankin department of chemistry and biochemistry, university of minnesota duluth, duluth, minnesota 55812, usa email. Bonding in hypervalent iodine compoundshypervalent iodine compounds will arange themselves so that the least electronegative group occupies an equatorial position. Julian lo hypervalent iodine baran group meeting 615 basic oxidations of alcohols to the corresponding carbonyl compounds. Carbonheteroatom bond formation mediated by hypervalent iodine 365. Rapid transformation of sulfinate salts into sulfonates. Primary alcohols rch 2oh can be oxidized either to aldehydes rcho or to carboxylic acids rco 2 h, while the oxidation of secondary alcohols r 1 r 2 choh normally terminates at the ketone r 1 r 2 co stage. Molecules free fulltext hypervalent iodinemediated ring.
Ibxtfoh mediated oxidation of alcohols to aldehydes and. Similarly, a stepwise protocol for the rittertype amination of alcohols via the formation of oxalic acid monoalkyl esters was also achieved. Hypervalent iodine tempo mediated oxidation in flow systems. Hypervalent iodine compounds catalyze various oxidation reactions such as the oxidation of alcohols, alpha oxidation of ketones, oxidative spirocyclization of phenols, etc. Hypervalent iodinemediated beckmann rearrangement of ketoximes r. Speedy and clean hypervalent iodinenitroxyl radical.
Hypervalent iodine reagents for the oxidation of alcohols and their application to complex molecule synthesis. Hypervalent iodineiii reagents in organic synthesis. A versatile and highly selective hypervalent iodine iii2,2,6,6tetramethyl1piperidinyloxyl mediated oxidation of alcohols to carbonyl compounds the journal of organic chemistry acs publications. Request pdf hypervalent iodinemediated oxidation of alcohols over the past two decades there has been a dramatic increse in the use of hypervalent. Jul 17, 20 herein, we describe the development of continuousflow systems using hypervalent iodine reagents in the tempo mediated oxidation of alcohols with the advantage of significantly shortened reaction times. Using a recyclable hypervalent iodine reagent 1, the authors have constructed versatile and green methods for the hypervalent iodine and nitroxyl radicalmediated selective oxidation of alcohols to aldehydes and ketones. Allylic and benzylic alcohols are cleanly oxidized to the corresponding carbonyl compounds in water or waterthf. A coppercatalyzed crossdehydrogenative coupling reaction between n hydroxyphthalimide and aldehydes using phioac 2 as an oxidant enables a synthesis of nhpi esters in good yields. In fact, the oxidized mediator can rely on an oxidation mechanism that is not available to the enzyme. Mechanistic investigations suggest that the reaction proceeds via the formation of an alkyl iodide and a higher oxidation state iodine iii species as key intermediates. Hypervalent iodine chemistry modern developments in organic synthesis. The chemistry of hypervalent halogen compounds wiley. Clean and highly selective oxidation of alcohols in an. Thus, any organoiodine compound with general formula ri e.
A variety of aromatic, aliphatic and conjugated alcohols were transformed to the corresponding carboxylic acids and ketones with a quantitative conversion in high yields with 70% tbuooh solution is water in the presence of catalytic amounts of la2o3. An excellent dual recycling strategy for the hypervalent. Mediated oxidation of alcohols cheminform abstract. Hypervalent iodinemediated oxidation of alcohols request pdf. In addition, a decarboxylative cn bond formation was achieved. Hypervalent iodineiii reagents in organic synthesis viktor v. Hypervalent iodineiii reagents in organic synthesis arkivoc. Recently, the hypervalent iodine compound, 1chloro1,2benziodoxol3one cbi has proved as an important reagent in organic synthesis. Phenol oxidation with hypervalent iodine reagents wikipedia. Carbonyl oxidation with hypervalent iodine reagents involves the functionalization of the. Results and discussion benzyl alcohol was chosen as a. Aerobic hypervalent iodine chemistry provides a strategy for coupling the oneelectron chemistry of o2 with twoelectron processes typical of organic synthesis. Speedy and clean hypervalent iodinenitroxyl radical mediated oxidation of alcohols using recyclable adamantane reagent with highly active 2.
Over the past two decades there has been a dramatic increse in the use of hypervalent iodine compounds in synthetic organic chemistry due to their mild and selective oxidizing properties. Hypervalent iodinemediated synthesis of spiroheterocycles. Results and discussion benzyl alcohol was chosen as a substrate in order to examine. The transformation is traditionally achieved by using chromiumbased reagents such as the collins reagent, activated manganese dioxide, or procedures known as the swern, pfitznermoffatt or parikhdoering oxidation. Both calculations and xray structures support this fact. A versatile and highly selective hypervalent iodine iii. Visiblelightinduced alkoxyl radical generation enables. The analysis of these papers reveals that products formed by an addition to the double bond is the most often observed reaction pathway. By utilizing a specific solvent and highly active 2azaadamantanenoxyl azado as an organocatalyst, we have improved the recycling protocol of the adamatane reagent 1 to be faster and more operationally simple for the hypervalent iodine nitroxyl radical mediated alcohol oxidation. Chiral hypervalent iodine mediated enantioselective oxidative. Hypervalent iodine compounds catalyze various oxidation reactions such as the oxidation of alcohols. Some commonly encountered hypervalent iodine reagents. Commonly proposed mechanisms for the iodineiiimediated oxidation of phenols. We have compiled authentic information from 20092016 regarding application of hypervalent iodine.
The recyclable reagent 1 having a unique tetraphenyladamantane structure exhibited almos. Several other oxidative processes have already been reported in flow chemistry 16. Facile and efficient oxidation of sulfides to sulfoxides in water using hypervalent iodine reagents. Hypervalent iodinemediated oxidation of alcohols find, read and cite all the research you need on. A versatile and highly selective hypervalent iodine iii2,2,6,6tetramethyl1piperidinyloxylmediated oxidation of alcohols to carbonyl compounds. Ibscatalyzed regioselective oxidation of phenols to 1,2. In particular, selective cascade oxidative transformations of alcohols to carbonyl compounds i.
Oxidative heteroatomheteroatom bond formation 307 luis bering and andrey p. User and ecofriendly hypervalent iodine reagent and. Chenjie zhu, lei ji, qian zhang and yunyang wei, catalytic hypervalent iodine oxidation of alcohols to the corresponding carbonyl compounds using n hydroxyphthalimide nhpi and m chloroperbenzoic acid, canadian journal of chemistry, 10. Oct 16, 2017 access to hypervalent iodine compounds a class of broadly useful chemical oxidants from o2 increases the scope of aerobic oxidation chemistry that can be achieved. Fibx see structure, the tetrafluoro derivative of the hypervalent iodine reagent, is more soluble and has higher reactivity than its nonfluorinated counterpart. This electrophilic intermediate may be attacked by a variety of nucleophiles or undergo rearrangement or elimination. In synthetic chemistry, selective methods for the oxidation of. The recyclable reagent 1 having a unique tetraphenyladamantane structure exhibited almost the same reactivity as the ordinary reagent, phenyliodine diacetate pida, in the. As a prelude to this article, we begin with a brief perspective of hypervalent iodine reagents in organic synthesis.
An efficient synthesis of fibx and initial reactions are presented. Trapping of either product is possible with a suitable reagent, and this method is often employed in tandem with a second process. However, as used in the context of organic synthesis, the term iodane more specifically refers to organoiodine compounds with nonstandard bond. Alternative mechanism proposed by felpin for the iodineiiimediated oxidation of aryl silyl ethers. Mechanistic studies suggest an unique reactivity of hypervalent iodine reagents in this ionic oxidative decarboxylation. Using a recyclable hypervalent iodine reagent 1, the authors have constructed versatile and green methods for the hypervalent iodine and nitroxyl radical mediated selective oxidation of alcohols to aldehydes and ketones. Herein, we describe the development of continuousflow systems using hypervalent iodine reagents in the tempo mediated oxidation of alcohols with the advantage of significantly shortened reaction times. This procedure allows an easy, convenient, highyielding method for the oxidation of alcohols starting from commercially available compounds. Some of these reactions can be conducted in standard organic solvents. Allylic and benzylic alcohols are cleanly oxidized to the corresponding carbonyl compounds in water or waterthf mixtures, or other mixtures, using a water. Iodane generally refers to any organic derivative of iodine.
Alcohol oxidation is an important organic reaction. Several other oxidative processes have already been reported in flow chemistry. This very mild system can efficiently mediate the oxidation of a range of alcohols to carbonyl compounds with a. Hypervalent iodine reagents for the oxidation of alcohols and. Iodine iii mediated halogenations of acyclic monoterpenoids five different halofunctionalizations of acyclic monoterpenoids were performed using a combination of a hypervalent iodine iii reagent and a halide salt. In combination with recyclable and reusable hypervalent iodine reactions, ruthenium catalysts could be used as a green and efficient catalytic oxidative system, for oxidation of alcohols and sulfides in water. Speedy and clean hypervalent iodinenitroxyl radical mediated. May 17, 20 herein, we describe the development of continuousflow systems using hypervalent iodine reagents in the tempo mediated oxidation of alcohols with the advantage of significantly shortened reaction times. A versatile and highly selective hypervalent iodine iii2,2,6,6. May 24, 2012 this protocol describes a practical laboratoryscale method for aerobic oxidation of primary alcohols to aldehydes, using a chemoselective cuitempo tempo 2,2,6,6tetramethyl1piperidinyloxyl. Phenol oxidation with hypervalent iodine reagents leads to the formation of quinonetype products or iodonium ylides, depending on the structure of the phenol. The catalytic system is compatible with a variety of substrates having arene, heteroarene and alkene functionalities. Facile and efficient oxidation of sulfides to sulfoxides in. Structure and kinetics of the reactive intermediates in the oxidation of alcohols and 1,2diols by oiodoxybenzoic acid ibx and dess.
Mediated oxidation of alcohols, cheminform on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Hypervalent iodineiiimediated oxidative decarboxylation of. An alternative method for forming sulfonates through hypervalent iodine iii reagent mediated oxidation of sodium sulfinates has been developed. Hypervalent iodine oxidation with hypervalent iodine reagents rearrangements mediated by hypervalent iodine reagents cc and cx bond formation mediated by hypervalent reagents electrochemistry synthetic organic electrochemistry electrochemical redox processes applications, setup and getting started hydrogen mediated reactions. A versatile and highly selective hypervalent iodine iii2,2,6,6tetramethyl1piperidinyloxyl mediated oxidation of alcohols to carbonyl compounds. Hypervalent iodinev derivatives such as 2iodoxybenzoic acid ibx and dessmartin periodinane dmp. A versatile and highly selective hypervalent iodine iii2,2. Chiral hypervalent iodine mediated enantioselective. Highly effective oxidation of benzyl alcohols to benzaldehydes over a new hypervalent iodine iii reagent with the polymeric framework and magnetic feature as reusable heterogeneous nanocatalyst. Oxidation of alcohols to carbonyl compounds plays an important role in organic chemistry. Copperitempocatalyzed aerobic oxidation of primary. Hypervalent iodine compounds catalyze various oxidation reactions such as the oxidation of alcohols, alphaoxidation of ketones, oxidative spirocyclization of phenols, etc.
Selected examples of this transformation are shown in table 3. Tertiary alcohols r 1 r 2 r 3 coh are resistant to oxidation the indirect oxidation of primary alcohols to carboxylic. The first part of this thesis discloses the synthesis of racemic spiropyrrolidines and spirolactams via oxidative amidation of corresponding naphtholic sulfonamides, employing dib as the oxidant. Oxidase catalysis via aerobically generated hypervalent. A versatile and highly selective hypervalent iodine iii2,2,6,6tetramethyl1piperidinyloxylmediated oxidation of alcohols to carbonyl compounds the journal of organic chemistry acs publications. An alternative method for forming sulfonates through hypervalent iodineiii reagentmediated oxidation of sodium sulfinates has been developed. The chemistry of hypervalent iodine macmillan group meeting july 30, 2003 sandra lee background and introduction n iodine is most commonly in monovalent compounds with an oxidation state of 1, however, because it is the largest, most polarizable, and most electropositive of the group 17 elements, it also forms. Kitamura electrophilic fluorination using hf as a source. Hypervalent iodinev reagents in organic synthesis arkivoc. The modified electrode was characterized by cyclic voltammetry cv. Recyclable reagents and catalytic systems based on.
Apr 09, 2020 ibxtfoh mediated oxidation of primary and secondary alcohols to carbonyls is reported. Oxidation of alcohols and amines 261 muhammet uyanik and kazuaki ishihara. We show that in contrast to the canonical twoelectron oxidation of aryl iodides, aerobic synthesis proceeds by a radical chain process initiated by the addition of aerobically generated acetoxy radicals to aryliodides to generate. The role of iodanyl radicals as critical chain carriers in. The common classification of hypervalent iodine iii reagents is according to the type of ligands attached to the iodine atom, as shown in figure 2. Stereoselective reactions of alkenes mediated by chiral. Cdppycfp electrode was successfully used in the oxidation of benzyl alcohol with tempo as the mediator. Aug 23, 2005 the present invention is a user and ecofriendly hypervalent iodine reagent mibx capable of selectively oxidizing allylic and benzylic alcohols in water and other ecofriendly solvents and having generally the following structure.
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