40473-49-2Relevant academic research and scientific papers
A base-promoted cascade reaction of α,β-unsaturated: N -tosylhydrazones with o -hydroxybenzyl alcohols: Highly regioselective synthesis of N-sec -alkylpyrazoles
Chen, Lian-Mei,Zhao, Juan,Xia, An-Jie,Guo, Xiao-Qiang,Gan, Ya,Zhou, Chuang,Yang, Zai-Jun,Yang, Jun,Kang, Tai-Ran
supporting information, p. 8561 - 8570 (2019/10/02)
An efficient method for the synthesis of N-sec-alkylpyrazoles through a base-promoted cascade cyclization/Michael addition reaction of α,β-unsaturated N-tosylhydrazones with ortho-hydroxybenzyl alcohols has been developed. The desired products containing di- or triaryl groups at the same carbon atom were afforded in good to excellent yields with excellent regioselectivities (>20:1). Moreover, a three-component reaction of ortho-hydroxybenzyl alcohols, α,β-unsaturated N-tosylhydrazones and saturated N-tosylhydrazones also took place to afford pyrazoles in good yields. This reaction offers a new route to triarylmethanes with a simple operation and is applicable for large-scale synthesis.
Organocatalytic Phosphonylation of in Situ Formed o-Quinone Methides
Huang, Hai,Kang, Jun Yong
supporting information, p. 5988 - 5991 (2017/11/10)
A new class of Br?nsted acid catalysts based on N-heterocyclic phosphorodiamidic acids (NHPAs) has been developed. The NHPA catalyst promotes phospha-Michael addition reaction of trialkylphosphites to in situ generated ortho-quinone methides (o-QMs) for t
Highly efficient preparation of optically active 5-hydroxy-3-oxoesters by enantioselective reaction of diketene with aldehydes promoted by novel chiral Schiff base-titanium alkoxide complexes
Hayashi,Tanaka,Oguni
, p. 1833 - 1836 (2007/10/03)
Optically active 5-hydroxy-3-oxoesters 1 can be obtained in up to 91% enantiomeric excess (e.e.) by the enantioselective reaction of diketene with aldehydes promoted by novel chiral Schiff base-titanium alkoxide complexes.
Quinone Dehydrogenation. Oxidation of Benzylic Alcohols with 2,3-Dichloro-5,6-dicyanobenzoquinone
Becker, Hans-Dieter,Bjoerk, Anders,Adler, Erich
, p. 1596 - 1600 (2007/10/02)
2,3-Dichloro-5,6-dicyanobenzoquinone (DDQ) reacts with primary and secondary aryl-substituted alcohols under mild conditions in dioxane solution to give the corresponding carbonyl compounds in high yields.In contrast to other oxidants, DDQ can be applied advantageously for the oxidation of hydroxyaryl-substituted alcohols.A mechanism involving participation of the phenolic hydroxyl group in the dehydrogenation reaction is discussed.Oxidations of hydroxyaryl-substituted alcohols by DDQ in methanolsolution resulting in the formation of benzoquinones by loss of the hydroxyaryl side chain are interpreted in terms of phenol oxidation.An example of a pyridine-catalyzed Smiles rearrangement of an o-hydroxy-substituted diphenyl ether is reported.
