Oxidative Rearrangement of Cyclic Tertiary Allylic Alcohols with IBX in DMSO

Shibuya, Masabumi; Ito, Shinichiro; Takahashi, M.; Iwabuchi, Yoshiharu

doi:10.1021/ol048210u

Cited by 82 publications

(43 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…When other catalysts such as piperidine, Et 3 N, DIPEA, methyl glycinate, pyridine, proline and proline derivatives were screened, no better result was obtained (Table 1, entries 3-9). Methyl glycinate (1e), a primary amine, was employed as a catalyst too, and the monocondensation product 4a was obtained in 22% yield (Table 1, Proline, a prominent catalyst, had been used previously in aldol reactions between cyclic ketones and aldehydes, but when proline was used in this reaction, no product was detected, and not even the aldol product was detected ( [10][11][12][13][14][15][16]. Although the reaction solvents influenced the rate of the reaction, they did not affect the formation of (E)-4a as single product during the course of reaction, regardless of the protic or aprotic nature of the solvent.…”

Section: Resultsmentioning

confidence: 99%

“…Thus, the synthesis of these compounds has attracted increasing attention from chemists, biochemists and pharmacologists. So far, several strategies are reported for the preparation of these compounds, which are accomplished by various methods such as condensation, oxidation, elimination, acylation, and insertion of carbon monoxide, among others [7][8][9][10][11][12][13][14][15]. In connection with a project in our laboratory, we required mono-2-arylidene derivatives of ketones, particularly of piperidone.…”

Section: Open Accessmentioning

confidence: 99%

See 1 more Smart Citation

Pyrrolidine-Mediated Direct Preparation of (E)-Monoarylidene Derivatives of Homo- and Heterocyclic Ketones with Various Aldehydes

Wang

et al. 2014

Molecules

View full text Add to dashboard Cite

An efficient method for the facile synthesis of (E)-monoarylidene derivatives of homo-and heterocyclic ketones with various aldehydes in the presence of a pyrrolidine organocatalyst has been achieved. A range of α,β-unsaturated ketones were obtained in moderate to high yields (up to 99%). Unlike the Claisen-Schmidt condensation process, the formation of undesired bisarylidene byproducts is not observed. The possible reaction mechanism suggests that the reaction proceeds via a Mannich-elimination sequence.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Open Accessmentioning

confidence: 99%

Pyrrolidine-Mediated Direct Preparation of (E)-Monoarylidene Derivatives of Homo- and Heterocyclic Ketones with Various Aldehydes

Wang

et al. 2014

Molecules

View full text Add to dashboard Cite

show abstract

“…Nevertheless, IBX (13) has also emerged as an efficient reagent for the oxygenation of benzylic C-H bonds, 14 phenols 15 and the oxidative rearrangement of allylic alcohols (F). 16 Furthermore, several methods involving in situ 35 formation of the active reagent have also been reported. 3b Since 2005, there are surprisingly few reports about the use of  3 iodanes for heteroatom transfer reactions.…”

mentioning

confidence: 99%

Benziodoxole-based hypervalent iodine reagents for atom-transfer reactions

et al. 2011

View full text Add to dashboard Cite

In the last decades, hypervalent iodine reagents have raised from chemical curiosities to mainstream reagents in organic synthesis. The use of benziodoxole-derived reagents has been especially successful in oxidation methods, whereas non-cyclic iodinanes have been used both for oxidation and atom-transfer reactions. On the other hand, the exceptional properties of 10 benziodoxole reagents for atom-transfer reactions have only started to attract the attention of the synthetic community more recently. In this review, progress in the use of these compounds for C-X and C-C bond formations will be presented. In particular, recent breakthroughs in trifluoromethylation and alkynylation reactions have been realized since 2006 bas ed on benziodoxole-derived reagents and these results are the main focus of this article.

show abstract

“…Natural catechol derivatives are easily oxidized by oxygen or chemical reagents. Benzeneseleninic anhydride, 17) 2-iodoxybenzoic acid (IBX) 18,19) and iodobenzene diacetate 20,21) are well known reagents for ortho-oxidation of phenol to give ortho-quinone or ortho-hydroxy-para-quinone methide, although sometimes a complex mixture is formed. Dibenzoyl peroxide is commonly used as an initiator of polymer synthesis and an effective reagent for ortho-oxidation of phenols to give catechol monoesters.…”

mentioning

confidence: 99%

Efficient <i>ortho</i>-Oxidation of Phenols with Diacyl Peroxides

Tada

Ishiguro

Izumi

2008

CHEMICAL & PHARMACEUTICAL BULLETIN

View full text Add to dashboard Cite

There are many natural catechols which show various biological activities, e.g., anti-oxidant, 1) anti-methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE),2) anti-tubercular, 3) anti-bacterial, [4][5][6][7][8][9] anti-plasmodial, 10) anti-viral, 11,12) anti-tumor, [13][14][15] and anti-platelet 16) activities. Natural catechol derivatives are easily oxidized by oxygen or chemical reagents. Benzeneseleninic anhydride, 17) 2-iodoxybenzoic acid (IBX) 18,19) and iodobenzene diacetate 20,21) are well known reagents for ortho-oxidation of phenol to give ortho-quinone or ortho-hydroxy-para-quinone methide, although sometimes a complex mixture is formed. Dibenzoyl peroxide is commonly used as an initiator of polymer synthesis and an effective reagent for ortho-oxidation of phenols to give catechol monoesters. However, dibenzoyl peroxide is unstable and has caused large explosions in industrial plants, e.g., at Itabashi in Japan (1990) and in northern Taiwan (2001). 22) In the previous synthesis of abietaquinone methide 3) (1) with anti-MRSA and anti-VRE activities, we reported ortho-oxidation of phenols using a stable diacyl peroxide, m-chlorobenzoyl peroxide (mCBPO, 2) which was synthesized from meta-chloroperbenzoic acid.23) The ortho-oxidation of a diterpene phenol with mCBPO gave the corresponding catechol ester in moderate yield, but the oxidation of other small phenols gave lower yields. We thus planned to improve the ortho-oxidation of phenols with diacyl peroxides, a stable and nontoxic reagent. We report herein a novel ortho-oxidation reaction of phenol using the asymmetric diacyl peroxide which was synthesized from m-chloroperbenzoic acid, together with the improvement of the yield of ortho-oxidation of phenols with the symmetric diacyl peroxide, mCBPO.ortho-Oxidation of Phenols with the Symmetric Diacyl Peroxide, mCBPO Previously, we synthesized abietaquinone methide 1, via the ortho-oxidation of ferruginol (3) with mCBPO at ambient temperature (Fig. 1).23) Some small phenols, e.g. o-cresol, m-cresol, p-cresol, 2,4-xylenol and 3,5-xylenol, however, were not oxidized with mCBPO at ambient temperature. Kubota and Takeuchi reported the unexpected formation of mCBPO 2 by the heating of mCPBA in dimethyl formamide (DMF) which was accompanied by an explosion.24) The formation of mCBPO after the explosion indicates that mCBPO is stable under high temperatures. In fact, solid mCBPO melts at over 110°C and exhibits slow foaming when heated in a glass tube. They also foresaw that severe explosion of mCBPO in DMF over 125°C from the differential thermal analysis, and improvement of the reaction condition using CH 2 Cl 2 solution to avoid the incident. Thus we tried the reaction of phenols with mCBPO at refluxing temperature of CH 2 Cl 2 and CHCl 3 . Phenols were safely oxidized with mCBPO even at refluxing temperature in chloroform. The reaction mixtures were reduced with LiAlH 4 (LAH) and then acetylated with acetic anhydride and pyridine. The mixture was chromatographed on s...

show abstract

Oxidative Rearrangement of Cyclic Tertiary Allylic Alcohols with IBX in DMSO

Cited by 82 publications

References 34 publications

Pyrrolidine-Mediated Direct Preparation of (E)-Monoarylidene Derivatives of Homo- and Heterocyclic Ketones with Various Aldehydes

Pyrrolidine-Mediated Direct Preparation of (E)-Monoarylidene Derivatives of Homo- and Heterocyclic Ketones with Various Aldehydes

Benziodoxole-based hypervalent iodine reagents for atom-transfer reactions

Efficient <i>ortho</i>-Oxidation of Phenols with Diacyl Peroxides

Contact Info

Product

Resources

About