- Acetalization of carbonyl compounds catalyzed by bismuth triflate under solvent-free conditions
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Carbonyl compounds were converted to the corresponding 1,3-dioxolanes and 1,3-dioxanes with ethylene glycol and 1,3-propandiol in the presence of bismuth triflate under solvent-free conditions. In addition, high chemoselective protection of aldehydes in the presence of ketones has been achieved.
- Aliyan, Hamid,Fazaeli, Razieh,Massah, Ahmad Reza,Momeni, Ahmad Reza,Naghash, Hamid Javaherian,Moeinifard, Behzad
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experimental part
p. 873 - 876
(2012/04/05)
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- Bismuth compounds in organic synthesis: Synthesis of dioxanes, dioxepines, and dioxolanes catalyzed by bismuth(III) triflate
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A simple method for the synthesis of 1,3-dioxolanes from carbonyl compounds has been developed using 1,2-bis(trimethylsilyloxy)ethane in the presence of bismuth(III) triflate as a catalyst. The bismuth(III) triflate catalyzed synthesis of a range of dioxanes and dioxepines has also been developed. In these latter cases, the carbonyl compound is treated with a diol, and triethyl orthoformate is used as a water scavenger. All these methods avoid the use of a Dean-Stark trap. Georg Thieme Verlag Stuttgart.
- Podgorski, Daniel M.,Krabbe, Scott W.,Le, Long N.,Sierszulski, Paul R.,Mohan, Ram S.
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experimental part
p. 2771 - 2775
(2010/10/02)
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- Highly efficient and chemoselective acetalization of carbonyl compounds catalyzed by new and reusab e zirconyl triflate, zr0(0tf)2
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Various types of aromatic aldehydes were efficiently converted to their corresponding 1,3-dioxanes and 1,3-dioxolane with 1,3-propanediol and ethylene glycol, respectively, in the presence of catalytic amount of ZrO(OTf) 2 in acetonitrile at room temperature. The catalyst can be reused several times without loss of its catalytic activity. Very short reaction times, selective acetalization of aromatic aldehydes in the presence of aliphatic aldehydes and ketones, very mild reaction conditions, reusability of the catalyst, and easy workup are noteworthy advantages of this method.
- Moghadam, Majid,Mohammadpoor-Baltork, Iraj,Tangestaninejad, Shahram,Mirkhani, Valiollah,Yazdani, Parvin,Ghorjipoor, Saeedeh
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experimental part
p. 131 - 135
(2009/09/30)
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- Highly efficient and chemoselective interchange of 1,3-oxathioacetals and dithioacetals to acetals promoted by N-halosuccinimide
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Highly efficient interconversion of a range of 1,3-oxathiolanes, 1,3-dithiolanes and 1,3-dithianes to their acetals at ambient temperature using N-bromosuccinimide or N-chlorosuccinimide and different types of alcohols and diols was investigated.
- Karimi, Babak,Seradj, Hassan,Maleki, Jafar
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p. 4513 - 4516
(2007/10/03)
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- Iodine-catalyzed, efficient and mild procedure for highly chemoselective acetalization of carbonyl compounds under neutral aprotic conditions
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Various types of carbonyl compounds are efficiently converted to their 1,3-dioxanes by the use of 1,3-bis(trimethylsiloxy)propane (BTSP) and a catalytic amount of iodine (3-7 mol%) under essentially neutral aprotic condition.
- Karimi, Babak,Golshani, Behzad
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p. 784 - 788
(2007/10/03)
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- Tetrabutylammonium tribromide (TBATB) as an efficient generator of HBr for an efficient chemoselective reagent for acetalization of carbonyl compounds
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Acyclic and cyclic acetals of various carbonyl compounds were obtained in excellent yields under a mild reaction condition in the presence of trialkyl orthoformate and a catalytic amount of tetrabutylammonium tribromide (TBATB) in absolute alcohol. Chemoselective acetalization of an aldehyde in the presence of ketone, unsymmetrical acetal formation, shorter reaction times, mild reaction conditions, the stability of acid-sensitive protecting groups, high efficiencies, facile isolation of the desired products, and the catalytic nature of the reagent make the present methodology a practical alternative.
- Gopinath, Rangam,Haque, Sk. Jiaul,Patel, Bhisma K.
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p. 5842 - 5845
(2007/10/03)
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- Zirconium tetrachloride (ZrCl4) catalyzed highly chemoselective and efficient acetalization of carbonyl compounds
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Zirconium tetrachloride (ZrCl4) is a highly efficient and chemoselective catalyst for the acetalization, and in-situ transacetalization of carbonyl compounds under mild reaction conditions.
- Firouzabadi, Habib,Iranpoor, Nasser,Karimi, Babak
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p. 321 - 323
(2007/10/03)
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- Efficient and chemoselective conversion of carbonyl compounds to 1,3-dioxanes catalyzed with N-bromosuccinimide under almost neutral reaction conditions
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(formula presented) Various types of carbonyl compounds were converted to the corresponding 1,3-dioxanes in the presence of ethyl orthoformate, 1,3-propanediol, and a catalytic amount of NBS via an in situ acetal exchange process. In contrast to conventional acid-catalyzed acetalization reactions, acid-sensitive substrates such as THP ethers and TBDMS ethers remain intact under described reaction conditions.
- Karimi, Babak,Ebrahimian, G. Reza,Seradj, Hassan
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p. 1737 - 1739
(2008/02/11)
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- Tungsten hexachloride (WCl6), a highly efficient and chemoselective catalyst for acetalization of carbonyl compounds
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Various types of aldehydes and ketones could be converted chemoselectively to their corresponding 1,3-dioxanes or diethyl acetals in the presence of catalytic amounts of tungsten hexachloride (WCl6) in good to excellent yields in CH2Cl2 or under neat conditions, respectively.
- Firouzabadi,Iranpoor,Karimi
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p. 2255 - 2263
(2007/10/03)
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