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(A) Synthesis
of 1,5-Benzodiazepines: Fujioka et al. developed a one-pot,
three-component reaction of aromatic aldehydes, 1,2-phenylenediamine,
and methyl acetoacetate in the presence of a catalytic acid producing
1,5-benzodiazepines.
[³]
This
reaction involves the γ-selective C-C bond formation
of methyl acetoacetate.
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(B) Synthesis
of Piperidines: Recently Khan et al. reported a convenient
method for the preparation of highly functionalized piperidines from
the combination of aromatic aldehydes, amines, and methyl acetoacetate
in the presence of a catalytic amount of bromodimethylsulfonium
bromide (BDMS).
[4]
Replacing methylacetoacetate
by diethyl malonate in the presence of the same catalyst yields
the Mannich-type products.
[5]
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(C) Synthesis
of Substituted Pyrazoles: Substituted pyrazoles have received
much attention because of their useful pharmacological properties.
Quian et al. reported a convenient synthesis of substituted pyrazoles
via a three-component condensation of phenylhydrazine, aldehydes,
and methyl acetoacetate using [Yb(PFO)3] as catalyst.
[6]
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(D) Synthesis
of Polyhydroquinolines: Kumar and co-workers synthesized polyhydroquinolines
using a four-component coupling reaction of cyclic 1,3-diketone,
aldehydes, methyl acetoacetate, and ammonium acetate in aqueous
micelles catalyzed by PTSA.
[7]
These derivatives
possess a variety of biological activities such as vasodilator,
branchodilator, antitumor, hepatoprotective, and geroprotactive
activity.
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(E) Multicomponent
One-Step Fusion of Biopertinent Pyrimidine Heterocycles: Biginelli’s
dihydropyrimidone (DHPM) synthesis has recently attracted a great
deal of attention since DHPM is an important heterocyclic motif
with a wide spectra of biological activities. Recently, Kwak and
co-workers developed an efficient, simple, and high-yielding protocol
for the synthesis of DHPMs and DHPM thiones involving a three-component,
one-pot assembly of aldehydes, methyl acetoacetate, and urea/thiourea
using readily available tetrachlorosilane as a catalyst.
[8]
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(F) One-Pot
Synthesis of Tetrahydropyridines: The multicomponent condensation
of methyl acetoacetate, acrolein and (S)-2-phenylglycinol
was found to provide a one-pot access to chiral 6-carbonyl-3-phenyl-2,3,8,8a-tetrahydro-7H-[1,3]oxazolo[3,2-a]pyridines
[9]
which are
proved to be useful intermediates for the preparation of various natural
products such as matrine, cytosine, and tashiromine.
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(G) Synthesis
of 4-Aryl-2-cyanoimino-3,4-dihydro-1H-pyrimidines: Recently,
Hulme et al. explored the construction of 4-aryl-2-cyanoimino-3,4-dihydro-1H-pyrimidine
(aryl-CIDHPM) compounds containing the N-cyanoguanidinyl moiety.
[¹0]
Methyl acetoacetate
has played a vital role in this reaction. The authors have explored
the multicomponent reaction of arene or hetero arenecarbaldehyde,
methyl acetoacetate, and cyanamide under acidic conditions for the
preparation of these compounds.
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(H) Synthesis
of β-acetamido carbonyl compounds: Khan et al. reported
a new methodology for the one-pot synthesis of β-acetamido carbonyl
compounds using aldehydes, methyl acetoacetate, acetonitrile/benzonitrile,
and acetyl chloride in presence of a Lewis acid catalyst.
[¹¹]
[¹²]
These compounds
are valuable building blocks for the preparation of 1,3-amino alcohols
or β-amino acids, as well as for the synthesis of various
bioactive molecules.
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