1435913-94-2Relevant academic research and scientific papers
: NBu4NPF6 promoted regioselective cascade synthesis of functionally embellished naphthofurans under acid, metal & solvent free conditions
Pareek, Abhishek,Dada, Ravikrishna,Rana, Monika,Sharma, Anuj K.,Yaragorla, Srinivasarao
, p. 89732 - 89743 (2016/10/03)
nBu4NPF6 mediated highly regioselective synthesis of functionally embellished naphthofurans has been achieved from easily available naphthols and propargyl alcohols through a cascade benzylation, oxacyclisation (5-exo dig) and isomerization under solvent free conditions. The reaction works in a short time through dibenzyl ether formation followed by the decomposition to the carbocation to furnish the high yielding products with large substrate scope. The synthetic utility of the products is demonstrated through C(sp3)-H functionalization. In addition, we investigated selected naphthofurans for their anti-amyloidogenic properties. Preliminary studies suggest that these are excellent inhibitors for amyloid formation, a hallmark for several neurodegenerative diseases.
Regiospecific synthesis of arenofurans via cascade reactions of arenols with Morita-Baylis-Hillman acetates of nitroalkenes and total synthesis of isoparvifuran
Kumar, Tarun,Mobin, Shaikh M.,Namboothiri, Irishi N.N.
, p. 4964 - 4972 (2013/06/27)
A cascade process involving an SN2′ reaction and an intramolecular oxa-Michael addition has been developed by treating Morita-Baylis-Hillman acetates of nitroalkenes with arenols, such as β-naphthols, α-naphthols, and substituted phenols under basic conditions. The products, arenofurans, are formed as single regioisomers in good to excellent yield in most cases. The methodology has been successfully employed for the total synthesis of an anti fungal agent isoparvifuran.
An efficient friedel-crafts/oxa-michael/aromatic annulation: Rapid access to substituted naphtho[2,1-b]furan, naphtho[1,2-b]furan, and benzofuran derivatives
Anwar, Shaik,Huang, Wan-Yun,Chen, Chih-Hao,Cheng, You-Song,Chen, Kwunmin
supporting information, p. 4344 - 4351 (2013/04/24)
Substituted naphthofurans and benzofurans are easily accessible by treatment of naphthols/substituted phenols with nitroallylic acetates through a substitution-elimination process promoted by cesium carbonate. Reactions between naphthols and aromatic/heteroaromatic-substituted nitroallylic acetates gave the desired functionalized naphthofurans in high to excellent chemical yields (14-97 %). On the other hand, treatment of phenol derivatives (i.e., 3-dimethylamino-, 3-methoxy-, and 3,5-dimethoxyphenol) with various nitroallylic acetates afforded the corresponding benzofurans in moderate to good chemical yields (24-91 %). The reaction proceeded through an interesting Friedel-Crafts SN2' process followed by intramolecular oxa-Michael cyclization and subsequent aromatization. A plot of log (k/kH) against Hammett constants σp showed satisfactory linearity with a positive ρ value, indicating that the initial Friedel-Crafts-type SN2' process constituted the rate-determining step. This methodology has been applied to the synthesis of various novel C2 and C3 symmetric bis- and trisfurans by using catechol and phloroglucinol as the nucleophilic partners. The reactivity decreased when alkyl-substituted nitroallylic acetate systems were used. This might be related to the decreased electrophilic character of these substrates. Copyright
