Multicomponent synthesis of C-tethered bispyrazol-5-ols using CeO2 nanoparticles as an efficient and green catalyst

Recent Developments on Five-Component Reactions

“…Safaei-Ghomi and coworkers developed a method for the synthesis of bis(pyrazol-5-ol) derivatives 67 using two equiv each of arylhydrazine, acetylenedicarboxylates and one equiv of aromatic aldehydes under the catalysis of CeO 2 nanoparticles ( Scheme 26 ) [ 42 ]. Nucleophilic reaction of arylhydrazine with acetylenedicarboxylates followed by cyclization form pyrazolone intermediate 68.…”

“…Safaei-Ghomi and coworkers developed a method for the synthesis of bis(py ol) derivatives 67 using two equiv each of arylhydrazine, acetylenedicarboxylates equiv of aromatic aldehydes under the catalysis of CeO2 nanoparticles (Scheme Nucleophilic reaction of arylhydrazine with acetylenedicarboxylates followed by tion form pyrazolone intermediate 68. Knoevenagel condensation of 68 and arom dehydes followed by Michael addition with 68 afford bis(pyrazol-5-ol) derivatives Xu group conducted a similar reaction using Dabco-base ionic liquid as a catalyst Safaei-Ghomi and coworkers developed a method for the synthesis of bis(pyrazol-5ol) derivatives 67 using two equiv each of arylhydrazine, acetylenedicarboxylates and one equiv of aromatic aldehydes under the catalysis of CeO 2 nanoparticles (Scheme 26) [42]. Nucleophilic reaction of arylhydrazine with acetylenedicarboxylates followed by cyclization form pyrazolone intermediate 68.…”

“…equiv of aromatic aldehydes under the catalysis of CeO2 nanoparticles (Scheme 26) [42]. Nucleophilic reaction of arylhydrazine with acetylenedicarboxylates followed by cyclization form pyrazolone intermediate 68.…”

A multi-component reaction for the direct access to 4,4'-(phenylmethylene)bis(1H-pyrazol-5-ol)-3-carboxylates using nano-NiZr4(PO4)6 in water

“…Therefore, the development of new MCR-based methodologies can be regarded as one of the most important facets of organic chemistry [12]. The synthesis of 1-phenyl-1Hpyrazol-5-ols has been reported using MCR in the presence of Ce(SO 4 ) 2 .4H 2 O [13], silica-bonded S-sulfonic acid [14], 1,3,5-tris(hydrogensulfato) benzene [15], 1sulfopyridinium chloride [16], acetic acid [17], and nano-CeO 2 [18]. Some of these methods have certain disadvantages, including long reaction times, use of toxic and non-reusable catalyst, and operation under speci c conditions [19,20].…”

CuFe2O4 and ZrP2O7 nanoparticles as highly efficient catalysts for the one-pot synthesis of phthalazine derivatives under solvent-free conditions

“…Multi-Component Reactions (MCRs) are highly exible, convergent, fruitful, and valuable for organic synthesis and they rapidly provide molecular complexity starting from simple substrates [22]. In addition, MCRs are environmentally friendly and play a prominent role in green chemistry [23][24]. Green chemistry emphasizes the need for environmentally clean synthesis, which involves reduction or elimination of the use or generation of hazardous chemicals and simple separation with recovery and reuse of reagents [25][26].…”