89559-96-6Relevant academic research and scientific papers
Lewis acid catalyzed acylation reactions: Scope and limitations
Chandra, Kusum L,Saravanan,Singh, Rajesh K,Singh, Vinod K
, p. 1369 - 1374 (2007/10/03)
Acylation of alcohols, thiols, and sugars were studied with a variety of Lewis acids, and it was found that Cu- and Sn(OTf)2 are very efficient in catalyzing the reaction under mild conditions. Among these two catalysts, Cu(OTf)2 was preferred because of its lower cost and relatively higher yield of the acylated product. The reaction was studied in several solvents, but CH2Cl2 was preferred. It was also observed that the present method is suitable for acylation of tertiary alcohols. Sugars were also acylated without any epimerization at the anomeric center. It is further shown here that this method is also suitable for selective acylation of primary or secondary alcohols over tertiary ones.
Manganese(II)- and (III)-mediated Free-radical Cyclisation of Alkenes, β-Keto Esters and Molecular Oxygen
Yamada, Takashi,Iwahara, Yoko,Nishino, Hiroshi,Kurosawa, Kazu
, p. 609 - 616 (2007/10/02)
The reactions of substituted ethenes with β-keto esters in the presence of a mixture of manganese(II) and manganese(III) acetates, and molecular oxygen yielded substituted 1,2-dioxan-3-ols 3 in 14-95percent yields.Cobalt(III) acetate, potassium permanganate, lead(IV) acetate, copper(II) acetate, chromium(VI) trioxide, thallium(III) acetate, ammonium cerium(IV) nitrate and iron(III) perchlorate were also used in place of manganese(III) acetate.Effects on the product yields of substituents in the alkenes and β-keto esters have been examined and reaction mechanisms are discussed.
Reaction of Olefins with α-Cyanoacetamide in the Presence of Manganese(III) Acetate
Sato, Hidehiko,Nishino, Hiroshi,Kurosawa, Kazu
, p. 1753 - 1760 (2007/10/02)
2-Butenamides and 2-buten-4-olides are formed by the reaction of phenyl or 4-chlorophenyl-substituted olefins with α-cyanoacetamide in the presence of manganese(III) acetate.On the other hand, aryl substituted olefins having electron-donating groups are oxidized under similar reaction conditions to give 1,5-dihydro-2H-pyrrol-2-ones and 3-ethenyl-2-pyrrolidones.All these reactions also produce glycols or ketones which are given by the direct oxidation of these olefins with manganese(III) acetate.The question whether an intermediate carbocation in the oxidation process cyclized on an oxygen or a nitrogen atom can be explained by the hard and soft acids and bases (HSAB) concept.A possible mechanism for the formation of 2-buten-amides and 2-buten-4-olides is proposed.
The Facile Synthesis of Dihydrofurans by the Oxidation of Olefins with Tris(2,4-pentanedionato)manganese(III)
Nishino, Hiroshi
, p. 1922 - 1927 (2007/10/02)
Eleven olefins were oxidized with tris(2,4-pentanedionato)manganese(III) at the reflux temperature to give the corresponding 3-acetyl-2-methyl-4,5-dihydrofurans in good yields.The oxidation of 9-benzylidene-9,10-dihydroanthracene under the same reaction conditions did not produce the corresponding dihydrofuran, but 9--9,10-dihydroxyanthracene.When 1,1-diphenylethene was oxidized at room temperature, 3-acetyl-2-hydroperoxy-2-methyl-5,5-diphenyltetrahydrofuran was obtained in a high yield.The effects of the solvent and the additives on the yield of dihydrofuran, the comparable reactivities of other (2,4-pentanedionato)metal complexes, such as Co(III), Cr(III), Fe(III), and Cu(II), and the reaction mechanism are discussed.
The Reaction of Olefins with Malonic Acid in the Presence of Manganese(III) Acetate
Ito, Nobuyuki,Nishino, Hiroshi,Kurosawa, Kazu
, p. 3527 - 3528 (2007/10/02)
The reaction of 1,1-diphenylethene with malonic acid in the presence of manganese(III) acetate gave 3,3,8,8-tetraphenyl-2,7-dioxaspirononane-1,6-dione and 4,4-diphenyl-2-(2,2-diphenylethenyl)-4-butanolide.Similar reactions with 1,1-bis(4-methoxyphenyl)ethene, methylenecyclohexane, 2-phenylpropene, 1-octene, and cyclohexene yielded the corresponding 2,7-dioxaspirononane-1,6-diones.
