A one-pot, three-component regiospecific synthesis of dispiropyrrolidines containing a thiophenone ring via 1,3-dipolar cycloaddition reactions of azomethine ylides

Survey reaction of 2-amino-N-(aryl) benzimidamides with ninhydrin in different conditions and investigation of reaction mechanism using density functional theory (DFT)

In this investigation, firstly, 1-(2-amino-phenyl)-N-(aryl) methane diamine derivatives were synthesized by reaction of 2-aminobenzo nitrile with aromatic amines in the presence of aluminum chloride as the catalyst. Then, the reaction of these intermediates with ninhydrin in different conditions was investigated. The reaction between ninhydrin and 2-amino-N'-(aryl) benzimidamide derivatives in water as solvent under reflux conditions resulted in the synthesis of diazepine derivatives. The same results were obtained when the reaction was done in EtOH and in the presence of a few drops of sulfuric acid at room temperature. Also, this reaction was carried out in ethanol as solvent without the presence of sulfuric acid at room temperature which resulted in the synthesis of spiro [indene-2,2'-quinazoline] derivatives. And finally, the reaction was carried out in ethanol as solvent without the presence of sulfuric acid at the reflux conditions which resulted in the synthesis of isoquinolino-quinazoline derivatives. These N-heterocycles compounds are important biologically. Mild reaction conditions, simple procedure and purification and also product diversity with changing conditions are important advantages of this method. Also, to better understanding reaction mechanism on the condensation reactions of 2-amino-N-(aryl) benzimidamides with ninhydrin in different conditions, density functional theory (DFT)-based quantum chemical methods have been applied. Calculated atomic charges suggest that the C-1 (+ 0.54 a.u.) center of ninhydrin is a better electrophile than C-2 (+ 0.42 a.u.) center.

Azomethine Ylides-Versatile Synthons for Pyrrolidinyl-Heterocyclic Compounds

Azomethine ylides are nitrogen-based three-atom components commonly used in [3+2]-cycloaddition reactions with various unsaturated 2π-electron components. These reactions are highly regio- and stereoselective and have attracted the attention of organic chemists with respect to the construction of diverse heterocycles potentially bearing four new contiguous stereogenic centers. This review article complies the most important [3+2]-cycloaddition reactions of azomethine ylides with various olefinic, unsaturated 2π-electron components (acyclic, alicyclic, heterocyclic, and exocyclic ones) reported over the past two decades.

Antimicrobial Activity and In Silico Molecular Docking Studies of Pentacyclic Spiro[oxindole-2,3′-pyrrolidines] Tethered with Succinimide Scaffolds

Three-component cascade reactions of (E)-3-arylidene-1-methyl-pyrrolidine-2,5-diones, L-valine and various isatin derivatives are described. A series of 17 spiropyrrolidine derivatives with wide structural complexity and diversity have been thus obtained in moderate to excellent yields under mild reaction conditions. The structure and stereochemistry of these N-heterocyclic cycloadducts has been established by spectroscopic techniques and unambiguously confirmed by a single-crystal X-ray diffraction analysis performed on one derivative. UV-visible spectra have been recorded for all new compounds. Furthermore, the synthesized N-heterocyclic compounds have been screened for their in vitro antibacterial and antifungal activities. Several derivatives exhibited moderate to good activities, comparable to those of the known standard drugs Amphotericin B and Tetracycline. Structural activity relationships (SARs) and molecular docking of the most promising derivatives into the binding sites of glucosamine 6-phosphate synthase (GlcN6P) and methionyl-trna-synthetase (1PFV) were also established. Furthermore, pharmacokinetic studies indicate that the heterocycles exhibit acceptable predictive ADMET (absorption, distribution, metabolism, excretion, and toxicity) properties and good drug ability.

A new Mumm-type rearrangement with dithiocarbamates via isocyanide-based multicomponent reaction under ultrasound irradiation: synthesis of polysubstituted pyrrolidine compounds

Through a domino reaction, five new bonds were formed, carbon–sulfur, two carbon–nitrogen, and two carbon–carbon bonds.

Diastereoselective construction of a functionalized dihydro-pyridazine-based spirooxindole scaffold via C-3 umpolung of isatin N,N′-cyclic azomethine imine

This study demonstrates an abnormal [3+3] tandem Michael addition/N-cyclization of isatin N,N′-cyclic azomethine imine 1,3-dipoles and 2-arylidene malononitrile that diastereoselectively construct a dihydro-pyridazine-based spirooxindole.

Efficient synthesis of novel antiproliferative steroidal spirooxindoles via the [3+2] cycloaddition reactions of azomethine ylides

A series of novel steroidal spirooxindoles 3a-h were synthesized from pregnenolone in a high regioselective manner using the 1,3-dipolar cycloaddition as the key step. This protocol resulted in the formation of two C-C bonds, one C-N bond and the creation of one pyrrolidine ring and three contiguous stereocenters in a single operation. Biological evaluation showed that these synthesized steroidal spirooxindoles exhibited moderate to good antiproliferative activity against the tested cell lines and some of them were more potent than 5-FU. Among them, compounds 3e and 3f displayed the best antiproliferative activity against MCF-7 cells with the IC50 values of 4.0 and 3.9μM, respectively. Flow cytometry analysis demonstrated that compound 3d caused the cellular apoptosis and cell cycle arrest at G2/M phase in a concentration-dependent manner. Docking results indicated that compound 3d fitted well into the MDM2 active site 1RV1 by interacting with Lys94 and Thr101 residues.

A strategic approach to the synthesis of functionalized spirooxindole pyrrolidine derivatives: in vitro antibacterial, antifungal, antimalarial and antitubercular studies

A series of spirooxindole pyrrolidine derivatives has been synthesized and evaluated for theirin vitrobiological activities. The observed regio- and stereoselectivity of the cycloaddition reaction has been rationalized using DFT calculations.

Design, synthesis and biological evaluation of novel steroidal spiro-oxindoles as potent antiproliferative agents

Two series of novel steroidal spiro-pyrrolidinyl oxindoles 3a-t and 6a-c were designed and synthesized from dehydroepiandrosterone using the 1,3-dipolar cycloaddition as the key step and further evaluated for their antiproliferative activities for four human cancer cell lines (MGC-803, EC109, SMMC-7721 and MCF-7). This protocol achieved the formation of two CC bonds, one CN bond and the creation of one new five-membered pyrrolidine ring and three contiguous stereocenters in a single operation. Biological evaluation showed that these synthesized steroidal spiro-pyrrolidinyl oxindoles possessed moderate to good antiproliferative activities against the tested cell lines and some of them were more potent than 5-Fu. Particularly, compound 3g showed good antiproliferative activity against SMMC-7721 (IC50=0.71μM). Steroid dimer 6b showed improved antiproliferative activities against SMMC-7721 and MCF-7 with the IC50 values of 4.30 and 2.06μM, respectively. Flow cytometry analysis demonstrated that compound 3n caused the cellular early apoptosis and cell cycle arrest at G2/M phase in a concentration- and time-dependent manner. [Corrected]