- Practical acetalization and transacetalization of carbonyl compounds catalyzed by recyclable PVP-I
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A novel PVP-I catalyzed acetalizations/transacetalizations of carbonyl compounds has been developed processing with a mild and easy handling fashion. Different types of Acyclic and cyclic acetals were prepared from carbonyl compounds or their acetals successfully. Further applications of newly developed catalytic combination were testified. This protocol featured with simplicity of operation, mild reaction condition, short reaction time, recyclable of catalyst and broad substrates scope with excellent yields.
- Cao, Fu-Rong,Lu, Guangying,Ren, Jiangmeng,Wang, Di,Zeng, Bu-Bing
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- Antimony(v) catalyzed acetalisation of aldehydes: An efficient, solvent-free, and recyclable process
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A highly selective, solvent-free process for the acetalisation of aldehydes was achieved by the use of a readily accessible antimony(v) catalyst which we previously prepared in our lab as a tetraarylstibonium triflate salt ([1][OTf]). High yields of the acetals were achieved in the presence of stoichimetric amounts of either triethoxymethane or triethoxysilane. It was found that triethoxymethane reactions required longer time to reach completion when compared to triethoxysilane reactions which were completed upon mixing of the reagents. The products can be easily separated from the catalyst by distillation which enabled further use of [1][OTf] in additional calytic reactions (up to 6 cycles). Moreover, [1]+ also catalyzed the deprotection of the acetals into their corresponding aldehydes using only water as a solvent.
- Ugarte, Renzo Arias,Hudnall, Todd W.
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p. 1990 - 1998
(2017/06/09)
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- Triarylborane-dipyrromethane conjugates bearing dual receptor sites: The synthesis and evaluation of the anion binding site preference
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The synthesis and optical properties of four new triarylborane- dipyrromethane (TAB-DPM) conjugates (3a-d) containing dual binding sites (hydrogen bond donor and Lewis acid) have been reported. The new compounds exhibit a selective fluorogenic response towards the F- ion. The NMR titrations show that the anions bind to the TAB-DPM conjugates via the Lewis acidic triarylborane centre in preference to the hydrogen bond donor (dipyrromethane) units.
- Swamy P., Chinna Ayya,Priyanka, Ragam N.,Thilagar, Pakkirisamy
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p. 4067 - 4075
(2014/03/21)
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- Iron(III) tosylate in the preparation of dimethyl and diethyl acetals from ketones and β-keto enol ethers from cyclic β-diketones
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An efficient method for conversion of ketones to their corresponding dimethyl and diethyl acetals and of cyclic β-diketones into β-keto enol ethers using Fe(OTs)3 as a catalyst is described. Copyright Taylor & Francis Group, LLC.
- Mansilla, Horacio,Afonso, Maria M.
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p. 2607 - 2618
(2008/12/22)
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- Gallium triiodide as a highly efficient and mild catalyst for the diethyl acetalization of carbonyl compounds
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Diethyl acetals were obtained from carbonyl compounds in good to excellent yields under mild reaction conditions in the presence of triethyl orthoformate and a catalytic amount of gallium triiodide in anhydrous ethanol.
- Ding, Jin-Chang,Xu, Rong,Liu, Miao-Chang,Chen, Xi-An,Wu, Hua-Yue
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experimental part
p. 566 - 568
(2009/07/18)
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- A new molecular iodine-catalyzed acetalization of carbonyl compounds
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A new and facile molecular iodine-catalyzed acetalization of carbonyl compounds has been developed. Useful selectivity has also been demonstrated.
- Basu, Manas K.,Samajdar, Susanta,Becker, Frederick F.,Banik, Bimal K.
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p. 319 - 321
(2007/10/03)
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- Substituted benzyl pyrimidines
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Compounds of the formula: STR1 in which R1 is lower alkoxy, R2 is bromine or lower alkoxy, and R3 is aryl, heteroaryl or a group --Q--R30, wherein Q is ethylene, vinylene or ethynylene and R30 is aryl, heteroaryl, lower alkoxycarbonyl or carbamoyl; hydrolyzable esters of carboxylic acids of formula I; and pharmaceutically acceptable salts of these compounds are useful for treating infectious diseases.
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- Substituted arylalkynyl-and heteroarylalkynl-N-hydroxyurea inhibitors of leukotriene biosynthesis
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The invention relates to compounds having activity to inhibit lipoxygenase enzyme activity, to pharmaceutical compositions comprising these compounds, and to a medical method of treating. More particularly, this invention concerns certain substituted arylalkynyl- and ((heteroaryl)alkynyl)-N-hydroxy-ureas which inhibit leukotriene biosynthesis, to pharmaceutical compositions of these compounds and to a method of inhibiting leukotriene biosynthesis.
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- [(SUBSTITUTED) PHENYALKYL]FURYLALKYNYL-AND [SUBSTITUTED)PHENYALKYL]THIENYLALKYNYL-N-HYDROXYUREA INHIBITORS OR LEUKOTRIENE BIOSYNTHESIS
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The present invention relates to compounds of the formula and the pharmaceutically acceptable salts thereof wherein Z is selected from optionally substituted phenyl, furyl, thienyl or thiazolyl; which inhibits leukotriene biosynthesis and is useful in the treatment of inflammatory disease states; also disclosed are leukotriene biosynthesis inhibiting compositions and a method for inhibiting 5-lipoxygenase activity and leukotriene biosynthesis
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