2,4,4,6-Tetrabromocyclohexa-2,5-dienone in the presence of triphenylphosphine as a regiospecific and stereoselective reagent for the nucleophilic substitution of bromine for hydroxyl

Matveeva, E. D.; Podrugina, T. A.; Зефиров, Н. С.

doi:10.1070/mc1998v008n01abeh000729

Cited by 8 publications

(5 citation statements)

References 7 publications

(7 reference statements)

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“…2,4,4,6-Tetrabromocyclohexa-2, 5-dienone was also successfully used in the nucleophilic substitution of bromine for hydroxyl; i.e., it served as a source of nucleophilic halogen in the presence of triphenylphosphine (Scheme 727). 2000 This reaction was performed with primary, secondary, sterically hindered, and cage alcohols to give high yields of the corresponding bromides. This reagent was found to be regiospecific, which was demonstrated for the replacement of the hydroxyl group in secondary and especially in branched secondary alcohols.…”

Section: Substitution Reactions With Other Bromo-organic Compoundsmentioning

confidence: 99%

Use of Bromine and Bromo-Organic Compounds in Organic Synthesis

2016

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Bromination is one of the most important transformations in organic synthesis and can be carried out using bromine and many other bromo compounds. Use of molecular bromine in organic synthesis is well-known. However, due to the hazardous nature of bromine, enormous growth has been witnessed in the past several decades for the development of solid bromine carriers. This review outlines the use of bromine and different bromo-organic compounds in organic synthesis. The applications of bromine, a total of 107 bromo-organic compounds, 11 other brominating agents, and a few natural bromine sources were incorporated. The scope of these reagents for various organic transformations such as bromination, cohalogenation, oxidation, cyclization, ring-opening reactions, substitution, rearrangement, hydrolysis, catalysis, etc. has been described briefly to highlight important aspects of the bromo-organic compounds in organic synthesis.

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Section: Substitution Reactions With Other Bromo-organic Compoundsmentioning

confidence: 99%

Use of Bromine and Bromo-Organic Compounds in Organic Synthesis

2016

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“…On the basis of the results of previous studies [1][2][3][4][5], we presumed that the reaction of triphenylphosphine with 2,4,4,6-tetrabromo-2,5-cyclohexadienone (I) can be regarded as a halophilic process [1] leading to formation of a complex which reacts with carboxylic acid to give acyloxyphosphonium intermediate II and 2,4,6-tribromophenol (III). The subsequent decomposition of intermediate II affords the corresponding acyl bromide and triphenylphosphine oxide (Scheme 1).…”

Section: IImentioning

confidence: 99%

Triphenylphosphine-2,4,4,6-tetrabromo-2,5-cyclohexadienone complex as a reagent for preparation of carboxylic acid bromides

et al. 2004

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Triphenylphosphine-2,4,4,6-tetrabromo-2,5-cyclohexadienone complex was successfully used as a new reagent for the synthesis of carboxylic acid bromides which were isolated as individual substances or were identified by conversion into the corresponding anilides. The reaction is chemoselective, and it can be applied to polyfunctional compounds, e.g., hydroxy acids. Scheme 1. IIRCOBr + Ph 3 PO RCOOH + Ph 3 P + O Br Br Br Br I [RCOOPPh 3 ] Br + OH Br Br Br III II

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“…Nevertheless, the good conversion implies that clean regeneration of dibenzophosphole takes place, in contrast to the reaction with tetrabromomethane. The majority of alternative reagents (i.e., bromine, [25] N-bromosuccinimide, [26] N-bromoacetamide, 2,4,4,6-tetrabromocyclohexa-2,5-dienone) [27] reacted quickly with diphenylsilane ( Figure 4). However, diethyl bromomalonate (DEBM, 17) reacted only slowly with diphenylsilane and was therefore selected for further investigations.…”

Section: Wwwchemeurjorgmentioning

confidence: 99%

In Situ Phosphine Oxide Reduction: A Catalytic Appel Reaction

Kalkeren

Leenders

Hommersom

et al. 2011

Chemistry A European J

162

121

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Several important reactions in organic chemistry thrive on stoichiometric formation of phosphine oxides from phosphines. To avoid the resulting burden of waste and purification, cyclic phosphine oxides were evaluated for new catalytic reactions based on in situ regeneration. First, the ease of silane-mediated reduction of a range of cyclic phosphine oxides was explored. In addition, the compatibility of silanes with electrophilic halogen donors was determined for application in a catalytic Appel reaction based on in situ reduction of dibenzophosphole oxide. Under optimized conditions, alcohols were effectively converted to bromides or chlorides, thereby showing the relevance of new catalyst development and paving the way for broader application of organophosphorus catalysis by in situ reduction protocols.

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2,4,4,6-Tetrabromocyclohexa-2,5-dienone in the presence of triphenylphosphine as a regiospecific and stereoselective reagent for the nucleophilic substitution of bromine for hydroxyl

Cited by 8 publications

References 7 publications

Use of Bromine and Bromo-Organic Compounds in Organic Synthesis

Use of Bromine and Bromo-Organic Compounds in Organic Synthesis

Triphenylphosphine-2,4,4,6-tetrabromo-2,5-cyclohexadienone complex as a reagent for preparation of carboxylic acid bromides

In Situ Phosphine Oxide Reduction: A Catalytic Appel Reaction

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