- Bis-chlorodibutyltin oxide as a new reagent for a mild, versatile and regioselective ring-opening of epoxides
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A convenient and efficient procedure for the ring-opening of epoxides by means of alcohols and bis-chlorodibutyltin oxide is described. The cleavage of the oxiranes is found to proceed regioselectively under mild reaction conditions. Thus, several haloalkanols, useful intermediates toward biological active molecules, are easily obtained in very good yields.
- Salomon
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- Efficient synthesis of chlorohydrins: Ionic liquid promoted ring-opening reaction of epoxides and TMSCl
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The environmentally benign, highly efficient synthesis of chlorohydrins by cleavage of epoxides using TMSCl in ionic liquid, bmimPF6, has been studied.
- Xu, Li-Wen,Li, Lyi,Xia, Chun-Gu,Zhao, Pei-Qing
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- BiCl3-mediated opening of epoxides, a facile route to chlorohydrins or amino alcohols: One reagent, two paths
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Opening of epoxides can be an effective means by which a variety of functional groups can be incorporated. In this letter, we outline how variation of conditions, in particular, that of solvent and concentration, give rise to different products using the Lewis acid catalyst BiCl3.
- McCluskey, Adam,Leitch, Sarah K.,Garner, James,Caden, Christine E.,Hill, Timothy A.,Odell, Luke R.,Stewart, Scott G.
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- Regioselective opening of epoxides catalyzed by Sn (IV). A new method for the synthesis of halohydrins?
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The regioselective opening of epoxides with organotin oxides 1 and 2, in presence of halogenated alcohols was developed, yielding the halohydrin derivatives.
- Salomon, Claudio J.
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- Precise Alkoxyamine Design to Enable Automated Tandem Mass Spectrometry Sequencing of Digital Poly(phosphodiester)s
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A major step towards reliable reading of information coded in the sequence of long poly(phosphodiester)s was previously achieved by introducing an alkoxyamine spacer between information sub-segments. However, MS/MS decoding had to be performed manually to
- Launay, Kévin,Amalian, Jean-Arthur,Laurent, Eline,Oswald, Laurence,Al Ouahabi, Abdelaziz,Burel, Alexandre,Dufour, Florent,Carapito, Christine,Clément, Jean-Louis,Lutz, Jean-Fran?ois,Charles, Laurence,Gigmes, Didier
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- Trihaloisocyanuric Acid/Triphenylphosphine: An Efficient System for Regioselective Conversion of Epoxides into Vicinal Halohydrins and Vicinal Dihalides under Mild Conditions
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A new synthetic method has been developed for the regioselective conversion of epoxides to vicinal chloro-/bromohydrins and vicinal dihalides by reaction with the system trihaloisocyanuric acid/tri?phenylphosphine in acetonitrile under mild and neutral conditions. The reactions proceed smoothly in high yield at room temperature and at reflux, respectively, over a short time.
- De Andrade, Vitor S. C.,De Mattos, Marcio C. S.
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- A tandem enzyme reaction to produce optically active halohydrins, epoxides and diols
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The recombinant halohydrin dehalogenase from Agrobacterium radiobacter AD1 was used to obtain enantiomerically pure halohydrins and epoxides by kinetic resolution. By adding an excess of the recombinant epoxide hydrolase from the same organism the reversible conversion was drawn to completion. Halohydrins such as (S)-2,3-dichloro-1-propanol (E>100) and (S)-2-chloro-1-phenylethanol (E=73) were obtained with an enantiomeric excess of higher than 99%. This is a novel biocatalytic route for obtaining enantiomerically pure aromatic halohydrins and epoxides.
- Lutje Spelberg, Jeffrey H.,Van Hylckama Vlieg, Johan E. T.,Bosma, Tjibbe,Kellogg, Richard M.,Janssen, Dick B.
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- Epoxide ring opening catalysed by imidochromium complexes
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tert-Butylimidochromium complexes catalysed ring opening of epoxides by SiMe3(N3) to give azidohydrins in good yields. The proposed mechanism for the chromium-mediated epoxide azidolysis involves the intermediacy of a chromium-azide species which delivers nucleophilic azide to the epoxide substrate. The azido complexes [{Cr(NBut)2Cl}2(μ-N3) 2] 1 and [Cr(ButN=NN=NSiMe3)(N3)Cl2] 2 have been isolated in the reactions of SiMe3(N3) with [Cr(NBut)2Cl2] and [Cr(NBut)Cl3(dme)] (dme = 1,2-dimethoxyethane), respectively. The structure of complex 1 has been established by X-ray crystallography. The mean Cr-N (imide) and Cr-N (azide) distances are 1.605 and 2.061 A, respectively. Reaction of [Cr(NBut)Cl3(thf)2] (thf = tetrahydrofuran) with (S,S)-diop {4,5-[bis(diphenylphosphino)methyl]-2,2-dimethyl-1,3-dioxolane} gave the dimeric complex [{Cr(NBut)Cl3}2{μ(S,S)-diop}], which has been characterised by X-ray crystallography. The Cr-N and Cr-P distances are 1.593(9) and 2.449(4) A, respectively.
- Leung, Wa-Hung,Wu, Man-Ching,Chim, Joyce L. C.,Yu, Man-Tat,Hou, Hong-Wei,Yeung, Lam-Lung,Wong, Wing-Tak,Wang, Yu
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- Reaction of epoxides with activated DMSO reagent. General method for synthesis of α-chlorocarbonyl compounds: Application in asymmetric synthesis of (3S)-2,3-oxidosqualene
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Reaction of a variety of epoxides with DMSO-Oxalyl chloride in the presence of a catalytic amount of methanol and a base was studied. Disubstituted epoxides gave α-chloroketones in high yields. Aliphatic terminal epoxide underwent opening reaction to provide α-chloroketone as a major product. Trisubstituted epoxides provided α-chloroketones as major products through the formation of more stable carbocation. In case of a homoallylic alcohol, enedione was obtained. The efficiency of the method was shown by applying it to the enantioselective synthesis of (3S)-2,3-oxidosqualene.
- Raina, Sushil,Singh, Vinod K.
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- Efficient Nucleophilic Cleavage of Oxiranes to Chlorohydrins
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SnCl2*2H2O-Mg and THF-H2O is an efficient system for the conversion of oxiranes into chlorhydrins.
- Sarangi, Chintamani,Das, Nalin B.,Nanda, Bhagabat,Nayak, Amaendu,Sharma, Ram P.
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- Trichloromethanesulfonyl chloride: A chlorinating reagent for aldehydes
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Trichloromethanesulfonyl chloride (CCl3SO2Cl), a commercially available reagent, has been found to perform efficiently in the α-chlorination of aldehydes, including its catalytic asymmetric version, under very mild reaction conditions. Under our reaction conditions, this compound outperforms typical chlorinating reagents for organic synthesis, facilitates workup and purification of the product, and minimizes the formation of toxic, chlorinated organic waste.
- Jimeno, Ciril,Cao, Lidong,Renaud, Philippe
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- Facile Conversion of Epoxides to Chlorohydrins with Titanium(IV) Chloride/1,8-Diazabicycloundec-7-ene
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A series of epoxides has been converted to the analogous chlorohydrins by treatment with titanium(IV) chloride and 1,8-diazabicycloundec-7-ene.This procedure tolerates acetal protecting groups normally labile to aqueous acids, and when used in conjunction with the Sharpless epoxidation protocols, it allows the preparation of chiral chlorodiols selectively protected at one hydroxy group.
- Spawn, Carol-Lynn,Drtina, Gary J.,Wiemer, David F.
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- Highly regio- and stereoselective synthesis of β-halohydrins from epoxides catalyzed with ceric ammonium nitrate
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Ce(IV) as ceric ammonium nitrate can effectively catalyze ring opening of epoxides with halides under very mild conditions and easy procedure to give the corresponding β-chloro- and β-bromohydrins in excellent yields. The reactions occur with both substituted and unsubstituted quaternary ammonium halides and with high regio- and stereoselectivity. The reaction of optically active styrene oxide with chloride ion was found to be highly stereospecific and afforded the corresponding β-halohydrin in 96% ee.
- Iranpoor,Kazemi,Salehi
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- Polyvinylpyrrolidone/thionyl chloride as a new polymeric reagent for facile conversion of epoxides to β-chlorohydrins
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Epoxides undergo rapid ring opening with cross-linked polyvinylpyrrolidone/thionyl chloride complex, under mild reaction condition to afford chlorohydrins in high yields.
- Tamami, Bahman,Ghazi, Iraj,Mahdavi, Hossein
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- A phosphonium ylide as a visible light organophotoredox catalyst
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A phosphonium ylide-based visible light organophotoredox catalyst has been designed and successfully applied to halohydrin synthesis using trichloroacetonitrile and epoxides. An oxidative quenching cycle by the ylide catalyst was established, which was confirmed by experimental mechanistic studies.
- Toda, Yasunori,Tanaka, Katsumi,Matsuda, Riki,Sakamoto, Tomoyuki,Katsumi, Shiho,Shimizu, Masahiro,Ito, Fuyuki,Suga, Hiroyuki
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supporting information
p. 3591 - 3594
(2021/04/14)
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- Selective monochlorination of unsymmetrical vicinal diols with chlorinated iminium chlorides
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Chlorinated iminium chlorides have been identified to promote the highly efficient and selective mono-chlorination of unsymmetrical vicinal diols. Vilsmeier reagent, namely, (chloromethylene)dimethyliminium chloride, enables highly reactive and regioselective chlorination of 1,2- and 1,3-diols featured one secondary benzylic hydroxy group and one primary aliphatic hydroxy group to give the corresponding 1,2- and 1,3-chlorohydrins. Viehe's salts (α,α-dichloro iminium salts) exhibit excellent reactivity and good selectivity for vicinal diols to give the corresponding chlorohydrin carbamates via a cyclic intermediate in situ. The chlorination protocols tolerate diverse functional groups, including halogens, naphthalene rings, nitro, and cyano. Moreover, the optical purity of chiral diols could be retained during this chlorination reaction.
- Li, Chengyang,Li, Xiaotong,Wang, Yu,Wu, Xiaoyu,Xie, Xiaomin,Yang, Liqun,Zhang, Zhaoguo
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- Use of allylzinc halide as a source of halide: Differential addition of nucleophiles to Ts-aziridines and aldehydes under similar reaction conditions
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We have observed that the allylic zinc halide under identical reaction conditions acts in different modes for different electrophiles. For Ts-aziridines the halide part of the allylic halide has been introduced as a nucleophile and for the carbonyl compou
- Chatterjee, Rana,Samanta, Satyajit,Mukherjee, Anindita,Santra, Sougata,Zyryanov, Grigory V.,Majee, Adinath
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supporting information
p. 276 - 283
(2019/01/04)
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- Visible-light-triggered Catalytic Halohydrin Synthesis from Epoxides and Trichloroacetonitrile by Copper and Iron Salts
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Preparation of vicinal halohydrins, in which copper or iron chlorides catalyze the ring-opening reaction of epoxides with visible light effectively, is described. The use of trichloroacetonitrile as a halogen source enables catalytic HCl generation under the mild conditions. This method can also be applied to the aziridine ring-opening reaction.
- Toda, Yasunori,Tanaka, Katsumi,Matsuda, Riki,Suga, Hiroyuki
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supporting information
p. 1469 - 1471
(2019/12/02)
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- Direct halogenation of alcohols with halosilanes under catalyst- and organic solvent-free reaction conditions
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A chemoselective method for the direct halogenation of different types of alcohols with halosilanes under catalyst- and solvent-free reaction conditions (SFRC) is reported. Various primary, secondary and tertiary benzyl alcohols and tertiary alkyl alcohols were directly transformed to the corresponding benzyl and alkyl halides, respectively, using chlorotrimethylsilane (TMSCl) and bromotrimethylsilane (TMSBr).
- Ajvazi, Njomza,Stavber, Stojan
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supporting information
p. 2430 - 2433
(2016/05/19)
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- Enantioselective Intramolecular Hydroacylation of Unactivated Alkenes: An NHC-Catalyzed Robust and Versatile Formation of Cyclic Chiral Ketones
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A highly enantioselective intramolecular N-heterocyclic carbene (NHC)-catalyzed hydroacylation reaction gives access to a range of cyclic ketones from unactivated olefin-substituted aldehydes (up to 99% ee). Remarkably, aliphatic aldehydes were also transformed efficiently in an NHC-catalyzed hydroacylation reaction for the first time. 100% Organic: A highly enantioselective N-heterocyclic carbene (NHC)-catalyzed intramolecular hydroacylation of aromatic and, more interestingly, aliphatic aldehydes with unactivated olefins offers access to a range of cyclic α-chiral ketones bearing quaternary centers. The reaction was found to be highly robust and proceeds with excellent yield in the presence of a diverse range of functional groups.
- Janssen-Müller, Daniel,Schedler, Michael,Fleige, Mirco,Daniliuc, Constantin G.,Glorius, Frank
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supporting information
p. 12492 - 12496
(2015/10/12)
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- Chemo-, regio-, and stereo-selective perfluoroalkylations by a Grignard complex with zirconocene
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The synthesis of highly reactive perfluoroalkyl Grignard reagents with early transition metal zirconocene complexes and their new types of highly chemo-, regio-, and stereo-selective perfluoroalkylation reactions are reported with epoxides in particular. The zirconocene complex is advantageous in activating the perfluoroalkyl Grignard species. The zirconocene·Grignard complexes were clarified by DOSY. Both 1H and 19F DOSY analyses show that the addition of MAO and dioxane to the mixture of RFMgCl and Cp2ZrCl2 connects Cp2Zr and RFMg to generate the zirconocene/perfluoroalkyl-Grignard/dioxane complex.
- Fujiu, Motohiro,Negishi, Kazuyuki,Guang, Jie,Williard, Paul G.,Kuroki, Shigeki,Mikami, Koichi
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supporting information
p. 19464 - 19468
(2015/11/27)
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- 1,3,2,4-diazadiphosphetidine-based phosphazane oligomers as source of P(III) atom economy reagents: Conversion of epoxides to vic -haloalcohols, vic -dihalides, and alkenes in the presence of halogen sources
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1,3,2,4-Diazadiphosphetidines (P1-P3), as easily prepared, stable, and heterogeneous P(III) compounds, were used for the efficient conversion of epoxides to vic-halohydrins, vic-dihalides, or alkenes in the presence of different halogen sources in CH3CN. Of these phosphazanes, P3 is most suitable and contains 4 phosphorous atoms with the advantage of having greater atom economy and its phosphorus oxide byproduct can be easily separated from the reaction mixture by simple filtration. The nitrogen atoms in this molecule can also act as acid scavengers in the reaction.
- Iranpoor, Nasser,Firouzabadi, Habib,Etemadidavan, Elham
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p. 1165 - 1173
(2014/10/16)
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- Addition of unactivated thiols to epoxides and oxetanes catalyzed by a rhenium-oxo complex
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A method for synthesizing β- and γ-hydroxy thioethers via addition of unactivated thiols to epoxides and oxetanes has been developed. This reaction is proposed to proceed through an unconventional mode of activation of the heterocycles. The transformation is catalyzed by ReO2I(PPh 3)2 affording β- and γ-hydroxy thioethers in moderate to excellent yield with excellent regioselectivity.
- Badiceanu, Alexandra D.,Garst, Alyson E.,Trubitt, Meredith E.,Nolin, Kristine A.
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- Synthesis of 3-arylcoumarins through N-heterocyclic carbene catalyzed condensation and annulation of 2-chloro-2-arylacetaldehydes with salicylaldehydes
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The condensation reaction of 2-chloro-2-arylacetaldehyde with salicylaldehyde catalyzed by N-heterocyclic carbene (NHC) leading to 3-arylcoumarin was studied. A number of 3-arylcoumarin derivatives were obtained in good to excellent yields via this umpolung reaction. This reaction is facile and experimentally simple and mild.
- Jiang, Yuansong,Chen, Wanzhi,Lu, Weimin
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p. 3669 - 3676
(2013/05/08)
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- Electrochemically induced titanocene-mediated reductive opening of epoxides
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A new method for chemo- and regioselective electrochemical reductive opening of epoxides yielding primary alcohols with titanocene dichloride as a catalyst has been elaborated.
- Nikitin, Oleg M.,Magdesieva, Tatiana V.
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scheme or table
p. 194 - 195
(2011/11/12)
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- Rearrangement of 5-phenylthiazolidine-2,4-diones to chiral α-ketoamides via α-elimination
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An unexpected reaction took place when 5-phenylthiazolidine-2,4-diones were treated in basic media to produce phenyl-α-ketoamides in good yields. The 5-phenylthiazolidine-2,4-diones used as reactants were achieved through a rearrangement, which took place in the corresponding N-acyloxazolidinethiones.
- Munive, Laura,Berns, Sylvain,Sansinenea, Estibaliz,Ortiz, Aurelio
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body text
p. 6041 - 6044
(2010/11/21)
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- Convenient synthesis of chlorohydrins from epoxides using zinc oxide: Application to 5,6-epoxysitosterol
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Efficient synthesis of protected and unprotected chlorohydrins has been achieved by ring opening of epoxides with acetyl/benzoyl chloride and TMSCl using a catalytic amount of ZnO as a reusable catalyst. The applicability of ZnO is further extended by performing the cleavage of the natural product 5,6-epoxysitosterol with acetyl chloride.
- Moghaddam, Firouz Matloubi,Saeidian, Hamdollah,Mirjafary, Zohreh,Javan, Marjan Jebeli,Farimani, Mehdi Moridi,Seirafi, Marjan
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experimental part
p. 157 - 163
(2009/09/30)
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- Facile, high regio- And chemoselective conversion of epoxides to β-chlorohydrins using chlorodiphenylphosphine under solvent-free conditions
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A new method is described for the mild and high regioselective conversion of epoxides to β-chlcrohydrins in high yields even in the presence of alcohols, carboxylic acids, oximes, amides, thiols and tetrahydropyranyl ethers using chlorodiphenylphosphine (ClPPh2) under solvent-free and neutral conditions at room temperature and in short reaction times. In addition, some other functional groups such as carbon-carbon double bonds, ester groups and also phenyl ring that are present in the epoxide molecules remain intact in this method.
- Aghapour, Ghasem,Afzali, Asieh,Salek, Fahimeh
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experimental part
p. 231 - 236
(2009/12/03)
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- Ionene-bound borohydrides: Efficient, selective, and versatile polymer-supported reducing agents
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Reduction of structurally different carbonyl compounds, such as aldehydes, ketones, α,β-unsaturated enals and enones, acid chlorides, and imines was accomplished efficiently using high capacity ionene based borohydride reagents. Aldehydes and imines were reduced to the corresponding alcohols and amines in excellent yields in methanol at ambient temperature while ketones and acid chlorides were reduced in iso-propanol and THF-MeOH at reflux. Chemoselective reduction of aldehydes over ketones was achieved successfully with these reagents. Complete regioselectivity was also observed in the reduction of α,β-unsaturated aldehydes and ketones.
- Lakouraj, Moslem M.,Tajbakhsh, Mahmood,Mahalli, Majid S.
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p. 117 - 123
(2008/09/21)
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- Synthesis of β-chlorohydrins in water
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2,4,6-Trichloro-1,3,5-triazine (TCT, cyanuric chloride) was found to mediate the regio- and stereoselective ring opening of epoxides in H 2O in the presence of morpholine at room temperature to afford the corresponding β-chlorohydrins in excellent yields (Table). The transformation is very simple, fast, efficient, and ecologically beneficial.
- Das, Biswanath,Venkateswarlu, Katta,Krishnaiah, Maddeboina
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p. 149 - 152
(2007/10/03)
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- Regio- and stereoselective ring opening of epoxides and aziridines using zirconyl chloride: An efficient approach for the synthesis of β-chlorohydrins and β-chloroamines
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Zirconyl chloride mediated regio- and stereoselective ring opening of epoxides and aziridines at room temperature affords the corresponding β-chlorohydrins and β-chloroamines, respectively in high yields. Copyright
- Das, Biswanath,Krishnaiah, Maddeboina,Venkateswarlu, Katta
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- An alternative regioselective ring-opening of epoxides to chlorohydrins mediated by chlorotitanium(IV) reagents
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A regioselective cleavage of various epoxides to vic-chlorohydrin isomers by using TiCl4 or TiCl4-Ti(O-i-Pr)4 complex was investigated. The less substituted alcohols, C2-attack products, were formed by the use of TiCl4 in CH2Cl2. On the other hand, the less substituted chlorides, Cl-attack products, were formed by using TiCI(O-i-Pr)3 in DMF. These regioselectivities depend on both the acidity of the Lewis acids and the polarity of the solvents.
- Nishitani, Kiyoshi,Shinyama, Kyoko,Yamakawa, Koji
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p. 191 - 197
(2008/09/17)
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- Regioselective synthesis of vic-halo alcohols and symmetrical or unsymmetrical vic-dihalides from epoxides using triphenylphosphine -N-halo imides
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A simple, novel, and highly regioselective cleavage of epoxides into vicinal halo alcohols and symmetrical or unsymmetrical dihalides is described using different stoichiometries of triphenylphosphine (PPh3) and N-halo succinimide (NXS) or N-halo saccharine (NXSac).
- Iranpoor, Nasser,Firouzabadi, Habib,Azadi, Roya,Ebrahimzadeh, Farzaneh
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- Silphos [PCl3-n (SiO2)n]: A heterogeneous phosphine reagent for the regioselective synthesis of vic-haloalcohols
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Silphos as a silica-based phosphine [PCl3-n (SiO 2)n] provides a practical method for the conversion of epoxides to vic-haloalcohols in the presence of molecular bromine, iodine, or N-halosuccinimides (NXS, X = Cl, Br, I) in CH3CN or under solvent-free conditions at r.t. The simple filtration of heterogeneous Silphos oxide from the reaction mixture affords the pure vic-haloalcohols with excellent yields. Copyright Taylor & Francis Group, LLC.
- Iranpoor, Nasser,Firouzabadi, Habib,Jamalian, Arezu
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p. 2615 - 2621
(2007/10/03)
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- Regioselective conversion of unsymmetrical terminal epoxides into vicinal chlorohydrins using dimethoxyboron chloride
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A highly regioselective synthesis of chlorohydrins by chlorinative cleavage of unsymmetrical epoxides utilizing dimethoxyboron chloride is described. Except for styrene oxide, all the terminal epoxides were regioselectively cleaved following a predominantly SN2-type reaction pathway favouring the formation of primary chlorides. In the case of styrene oxide, a benzylic epoxide, (MeO)2BCl transfers the chlorine at the benzylic position, by following an apparent SN1-type mechanism. CSIRO 2006.
- Roy, Chandra D.
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p. 834 - 836
(2007/10/03)
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- Reduction of acid chlorides using dichloro bis[(1,4-diaza bicyclo [2.2.2] octane) bis(tetrahydroborato)] zirconium (IV)
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Aliphatic and aromatic acid chlorides were efficiently reduced to give the corresponding alcohols when treated with [Zr(BH4)2Cl 2(dabco)2], (ZrBDC).
- Alinezhad, Heshmatollah,Tajbakhsh, Mahmood,Salehian, Fatemeh
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p. 814 - 815
(2007/10/03)
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- Facile and regioselective conversion of epoxides into β-chlorohydrins using ZrCl4
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Epoxides were efficiently converted into the corresponding β-chlorohydrins in good yields by treatment with ZrCl4 in acetonitrile.
- Smitha,Reddy, Ch. Sanjeeva
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p. 300 - 301
(2007/10/03)
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- Green protocol for the synthesis of vicinal-halohydrins from oxiranes using the [Bmim]PF6/LiX reagent system
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Epoxides undergo rapid ring-opening with lithium halides in [bmim]PF 6 or [bmim]BF4 ionic liquids under mild and neutral conditions to afford the corresponding vic-halohydrins in high to quantitative yields. The epoxides show enhanced reactivity in ionic liquids thereby reducing reaction times and improving the yields significantly. The recovered ionic liquid can be reused in three to four subsequent runs with consistent activity.
- Yadav,Reddy,Reddy, Ch. Srinivas,Rajasekhar
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p. 476 - 477
(2007/10/03)
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- Selective conversion of epoxides to vic-halo alcohols and symmetrical or unsymmetrical dihalides by triphenylphosphine/2,3-dichloro-5,6-dicyano-1,4- benzoquinone (DDQ) in the presence of quaternary ammonium halides
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A new method is described for the efficient and selective conversion of epoxides to vic-halo alcohols or symmetrical and unsymmetrical dihalides using PPh3/DDQ/R4NX (X = Cl, Br, I) as a mixed-reagent system.
- Iranpoor, Nasser,Firouzabadi, Habib,Aghapour, Ghasem,Nahid, Azarmidokht
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p. 1885 - 1891
(2007/10/03)
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- Micellar media for the efficient ring opening of epoxides with CN-, N3-, NO3-, NO2-, SCN-, Cl- and Br- catalyzed with Ce(OTf)4
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Micellar media are introduced for the efficient ring opening of epoxides with sodium salts of nucleophiles such as CN, N3-, NO3-, NO2, SCN, Br and Cl-, catalyzed with Ce(OTf)4. This method is an efficient procedure for the synthesis of different β-substituted alcohols under mild reaction conditions. The reaction with SCN- is an easy procedure for the high yielding preparation of epoxy sulfides.
- Iranpoor, Nasser,Firouzabadi, Habib,Shekarize, Marzieh
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p. 724 - 727
(2007/10/03)
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- 1,2-Ferrocenediylazaphosphinines 2: A new class of nucleophilic catalysts for ring-opening of epoxides
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1,2-Ferrocenediylazaphosphinines (1a-c) have been successfully employed as a new class of nucleophilic catalysts for ring-opening of a range of epoxides, their catalytic efficiency in terms of regioselectivity as well as chemical yield comparing well with the existing catalysts in the literature. In contrast, low enantiomeric excesses have been obtained from the reactions of meso-epoxides catalyzed by (R)-1.
- Paek, Seung Hwan,Shim, Sang Chul,Cho, Chan Sik,Kim, Tae-Jeong
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p. 849 - 851
(2007/10/03)
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- Demonstration of a phosphazirconocene as a catalyst for the ring opening of epoxides with TMSCI
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(Matrix presented) In this study, it was demonstrated for the first time that a phosphazirconocene catalyzes the ring opening of epoxides with TMSCI. This reactivity leads to a facile preparation of chlorohydrins. The late transition metal Fe analogue was found to catalyze the reaction at rates and stereoselectivity comparable to those of the Zr complex.
- Wang, Li-Sheng,Hollis, T. Keith
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p. 2543 - 2545
(2007/10/03)
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- Highly regioselective ring opening of epoxides and aziridines using cerium(III) chloride
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A wide variety of epoxides and aziridines were converted to the corresponding β-halohydrins and β-haloamines using cerium(III) chloride and the cerium(III) chloride/NaI system in acetonitrile. The reactions were highly regioselective and efficient with excellent yields under mild and neutral reaction conditions.
- Sabitha, Gowravaram,Satheesh Babu,Rajkumar,Reddy,Yadav
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p. 3955 - 3958
(2007/10/03)
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- Iron(III) trifluoroacetate as an efficient catalyst for solvolytic and nonsolvolytic nucleophilic ring opening of epoxides
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Iron(III) trifluoroacetate was used as an efficient and nonhygroscopic catalyst for the alcoholysis, hydrolysis, and acetolysis of epoxides. The addition of chloride, bromide, iodide, and nitrate ions to epoxides to produce the corresponding 2-halo and 2-nitratoalkanols and also the conversion of epoxides to acetonides and thiiranes were also performed efficiently in the presence of this catalyst.
- Iranpoor, Nasser,Adibi, Hadi
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p. 675 - 680
(2007/10/03)
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- Solvent-free organic reactions on silica gel supports. Facile transformation of epoxides to β-halohydrins with lithium halides
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The reaction of epoxides with lithium halides was efficiently promoted on the surface of silica gel in the absence of any solvent to give the corresponding β-halohydrins. The reactivity of lithium halides was shown to follow the order LiI > LiBr >> LiCl, and the reactivity of LiCl was dramatically increased by adding an equivalent amount of water to this system. On the other hand a similar reaction with α,β-epoxyketones produces the α-haloenone derivatives, presumably via halohydrin intermediates. The epoxide-opening reaction of (R)-(+)-styrene oxide was also investigated to clarify the stereochemical features of this reaction.
- Kotsuki, Hiyoshizo,Shimanouchi, Tomoyasu,Ohshima, Reiji,Fujiwara, Shunsuke
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p. 2709 - 2722
(2007/10/03)
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- A general approach towards 2-substituted 3-hydroxy propanoates; application to the synthesis of methyl tropinate
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Enantiomerically pure R or S 2-substituted 3-hydroxy propanoates may be prepared by regioselective BF3 promoted opening of homochiral styrene oxide by lithium cyanocuprates followed by oxidative cleavage of the aromatic moiety with catalytic ru
- Imogai, Hassan,Larcheveque, Marc
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p. 965 - 972
(2007/10/03)
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- Selective manganese-mediated transformations using the combination: KMnO4/Me3SiCl
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A novel manganese reagent, generated from KMnO4 and Me3SiCl, in the presence of a quaternary ammonium salt, is shown to smoothly dichlorinate alkenes, open epoxides and chemoselectively oxidise sulfides to sulfoxides.
- Marko, Istvan E.,Richardson, Paul R.,Bailey, Mark,Maguire, Anita R.,Coughlan, Niall
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p. 2339 - 2342
(2007/10/03)
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- FeCl3·6H2O supported on SiO2 catalysed ring opening of epoxides with alcohols, acetic acid, water, chloride, bromide and nitrate ions
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FeCl3·6H2O absorbed on chromatographic silica gel can act as an efficient catalyst for alcoholysis, hydrolysis and acetolysis of epoxides. Methanolysis of (R)-styrene oxide proceeds with high stereospecificity and in excellent yield. This catalyst can also convert epoxides to their corresponding β-halohydrins and β-nitrato alcohols in the presence of chloride, bromide and nitrate ions respectively.
- Iranpoor, Nasser,Tarrian, Tahere,Movahedi, Zarangiz
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p. 1473 - 1476
(2007/10/03)
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- A facile conversion of epoxides to β-halohydrins with silica gel-supported lithium halides
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A variety of epoxides are efficiently converted to the corresponding β-halohydrins with lithium halides supported on silica gel in dry media.
- Kotsuki, Hiyoshizo,Shimanouchi, Tomoyasu
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p. 1845 - 1848
(2007/10/03)
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