Reaction of alk-3-yn-1-ones with o-phenylenediamines provides an effective method with high atom economy for the synthesis of diversely substituted benzodiazepines and conjugated enaminones. This ...microwave-accelerated reaction proceeds in ethanol in the absence of a catalyst and leads to benzyl-substituted 1,5-benzodiazepines with good yields (70-92%). A room temperature protocol with the same set of reagents (stabilized with triethylamine) leads to enaminones (3-amino-2-alkenones, 70-99%). The tautomer formed and the regio- and stereochemistry of the process are confirmed by the X-ray crystallographic structure determination of 2-(4-methylbenzyl)-4-phenyl-3H-benzob1,5diazepine and (Z)-3-(2-amino-4,5-dimethylphenyl)amino-4-(4-tert-butylph enyl)-1-(4-chlorophenyl)but-2-en-1-one.
5-Exo-dig cyclocondensation of alk-3-yn-1-ones with hydrazines, in the presence of montmorillonite K-10, provides an effective method with a high atom economy for the synthesis of diversely ...1,3,5-trisubstituted pyrazoles. The microwave-accelerated reaction proceeds in the absence of solvent and leads to 5-benzyl substituted pyrazoles with good yields (72-91%). The regiochemistry of the process was confirmed by the X-ray crystallographic structure determination of 1-(2-fluorophenyl)-5-(4-methylbenzyl)-3-phenyl-1H-pyrazole.
The reaction of alk-3-yn-1-ones (a bifunctional reagent) with o -phenylenediamines provides an effective synthetic method with high atom economy for the preparation of diversely substituted 1,5-3 H ...-benzodiazepines. The reaction initially leads to the formation of conjugated enaminones (3-amino-2-alkenones, 51–99%), at room temperature, which constitutes a formal non-catalyzed hydroamination of the non-conjugated alkyne. Non-symmetrical o -phenylenediamines react in a regioselective fashion with respect to amino groups. Both the direct microwave-accelerated reaction of o -phenylenediamines with alkynones in ethanol and the intramolecular cyclization of intermediate enaminones in ethanol/acetic acid lead to substituted 1,5-benzodiazepines with good yields (39–92 and 26–99%). The regio- and stereochemical outcomes of these processes are confirmed by the X-ray structure determination of ( Z )-3-(2-amino-4-methylanilino)-4-(4-methylphenyl)-1-phenylbut-2-en-1-one, 4-(4-methylphenyl)methyl-7-nitro-2-phenyl-3 H -1,5-benzodiazepine and 6,8-dimethyl-4-(4-methylbenzyl)-2-phenyl-3 H -benzo b 1,5diazepine.
Reaction of alk-3-yn-1-ones with
o
-phenylenediamines provides an effective method with high atom economy for the synthesis of diversely substituted benzodiazepines and conjugated enaminones. This ...microwave-accelerated reaction proceeds in ethanol in the absence of a catalyst and leads to benzyl-substituted 1,5-benzodiazepines with good yields (70-92%). A room temperature protocol with the same set of reagents (stabilized with triethylamine) leads to enaminones (3-amino-2-alkenones, 70-99%). The tautomer formed and the regio- and stereochemistry of the process are confirmed by the X-ray crystallographic structure determination of 2-(4-methylbenzyl)-4-phenyl-3
H
-benzo
b
1,5diazepine and (
Z
)-3-(2-amino-4,5-dimethylphenyl)amino-4-(4-
tert
-butylphenyl)-1-(4-chlorophenyl)but-2-en-1-one.
Reaction of alk-3-yn-1-ones with
o
-phenylenediamines provides an effective method with high atom economy for the synthesis of diversely substituted benzodiazepines and conjugated enaminones.
5-
Exo-dig
cyclocondensation of alk-3-yn-1-ones with hydrazines, in the presence of montmorillonite K-10, provides an effective method with a high atom economy for the synthesis of diversely ...1,3,5-trisubstituted pyrazoles. The microwave-accelerated reaction proceeds in the absence of solvent and leads to 5-benzyl substituted pyrazoles with good yields (72-91%). The regiochemistry of the process was confirmed by the X-ray crystallographic structure determination of 1-(2-fluorophenyl)-5-(4-methylbenzyl)-3-phenyl-1
H
-pyrazole.
Tandem condensation/5-
exo-dig
cyclization reactions of propargyl ketone with hydrazines gives easy access to 1,3,5-unsymetrically substituted pyrazoles.
The reaction of alk-3-yn-1-ones (a bifunctional reagent) with
o
-phenylenediamines provides an effective synthetic method with high atom economy for the preparation of diversely substituted 1,5-3
H
...-benzodiazepines. The reaction initially leads to the formation of conjugated enaminones (3-amino-2-alkenones, 51-99%), at room temperature, which constitutes a formal non-catalyzed hydroamination of the non-conjugated alkyne. Non-symmetrical
o
-phenylenediamines react in a regioselective fashion with respect to amino groups. Both the direct microwave-accelerated reaction of
o
-phenylenediamines with alkynones in ethanol and the intramolecular cyclization of intermediate enaminones in ethanol/acetic acid lead to substituted 1,5-benzodiazepines with good yields (39-92 and 26-99%). The regio- and stereochemical outcomes of these processes are confirmed by the X-ray structure determination of (
Z
)-3-(2-amino-4-methylanilino)-4-(4-methylphenyl)-1-phenylbut-2-en-1-one, 4-(4-methylphenyl)methyl-7-nitro-2-phenyl-3
H
-1,5-benzodiazepine and 6,8-dimethyl-4-(4-methylbenzyl)-2-phenyl-3
H
-benzo
b
1,5diazepine.
Reaction of alk-3-yn-1-ones with non-symmetrical
o
-phenylenediamines provides an effective method with high atom economy for the synthesis of diversely substituted 1,5-benzodiazepines and conjugated enaminones.
