Hypervalent Iodine(III) Sulfonate Mediated Synthesis of 2‐Arylimidazo[1,2‐a]Pyrimidines in Liquid PEG‐400

PEG‐400[poly(ethylene glycol‐400)] is used as a “green” recyclable solvent in the one‐pot synthesis of 2‐arylimidazo[1,2‐a]pyrimidines by reaction with ketones, [hydroxyl(2,4‐dinitrobenzenesulfonyloxy)‐iodo]benzene (HDNIB), and 2‐aminopyrimidine. Significant rate enhancements and improved yields have been observed.     

Hypervalent Iodine(III) Sulfonate Mediated Synthesis of Quinoxalines in Liquid PEG‐400

PEG‐400[poly(ethylene glycol‐400)] is used as a “green” recyclable solvent in the one‐pot synthesis of quinoxalines by reaction with aryl ketones, hypervalent Iodine(III) Sulfonate, and o‐phenylenediamines. Significant rate enhancements and improved yields have been observed.     

Hypervalent Iodine(III) Sulfonate Mediated Synthesis of Imidazo[1,2‐a]pyridines

A direct and efficient method for the conversion of alkyl aryl ketones to imidazo[1,2‐α]pyridines has been developed based on initial formation of α‐organosulfonyloxy ketones and their subsequent cyclocondensation by 2‐aminopyridines in one‐pot conditions.     

Hypervalent Iodine(III) Sulfonate Mediated Synthesis of α‐Thiocynanatoketones in a Task‐Specific Ionic Liquid [bmim]SCN

The task‐specific ionic liquid (TSIL) and 1‐n‐butyl‐3‐methylimidazolium thiocynanate, ([bmim]SCN) were used as the medium as well as the reactant for the synthesis of α‐thiocynanatoketones by the reaction with α‐sulfonyloxy aryl ketones. Significant rate enhancements and improved yields have been observed.     

Hypervalent Iodine(III) Sulfonate Reagent Mediated Synthesis of 4‐Aryl‐2‐Phenyloxazoles in Ionic Liquid

A new and efficient method for the synthesis of 4‐aryl‐2‐phenyloxazoles is described which is based upon the reaction of α‐[(2,4‐dinitrobenzene)sulfonyl]oxy ketone intermediates with benzamide in ionic liquid.     

Hypervalent Iodine(III) Reagent Mediated Synthesis of 2‐Methylbenzofuran Derivatives by Pummerer‐type Reaction in Ionic Liquid

An efficient route for the synthesis of 2‐methylbenzofuran derivatives utilizing hypervalent iodine(III) reagent and a‐(methylthio)acetone via Pummerer‐type reaction in ionic liquid is described.     

Polymer‐Supported Hypervalent Iodine Reagent Mediated Synthesis of α‐Azidoketones

The reaction of aryl ketones with sodium azide using polymer‐supported bis(trifluoroacetoxyiodo)‐benzene (PSBTI) in the presence of trifluoroacetic acid (TFA) to prepare α‐azidoketones in one‐pot conditions is reported.     

A Novel,Simple and Efficient Synthesis of 3‐Amino‐Benzo[d]imidazo[2,1‐b]Thiazole Derivatives via a Multicomponent Procedure

3‐Amino‐benzo[d]imidazo[2,1‐b]thiazoles were synthesized in moderate to good yields in the presence of NH₄Cl via a one pot procedure. All the products were characterized by ¹H NMR, IR, HRMS.     

Iodobenzene‐Catalyzed Synthesis of α‐Azidoketones and α‐Thiocyanatoketones from Aryl Ketones with MCPBA as a Cooxidant

Iodobenzene‐catalyzed synthesis of α‐azidoketones and α‐thiocyanatoketones from aryl ketones with MCPBA as a cooxidant is described. The method is simple, rapid and practical, generating α‐azidoketones and α‐thiocyanatoketones from the aryl ketone without isolation of α‐tosyloxyketones in good to excellent yields.     

One‐pot Synthesis of Benzamidonaphtho[2,1‐b]furans and Benzamidobenzo[b]furans as Novel Polycyclic Heteroaromatic Compounds

An operationally simple, green and efficient procedure for one‐pot synthesis of novel polycyclic heteroaromatic compounds such as benzamidonaphtho[2,1‐b]furans and benzamidobenzo[b]furans has been developed from the reaction of arylglyoxals, benzamide, and phenols. The reactions were mediated with low amounts of yttrium nitrate hexahydrate as a suitable Lewis acid catalyst without using solvent.     

Iodine-promoted direct sulfenylation of 2,3-dihydroimidazo[2,1-b]thiazoles with disulfides

A novel and facile method for the direct sulfenylation of 2,3-dihydroimidazo[2,1-b]thiazoles with disulfides has been developed. The transformation is promoted by iodine under metal-free conditions, providing the corresponding products in moderate to good yields.     

Facile Synthesis of Naphtho[2,3‐d]thiazoles,Naphtho[2,3‐e][1,3,4]thiadiazines and Bis(naphtho[2,3‐d]thiazolyl)copper(II) Derivatives from Heteroylthiosemicarbazides

A one step synthesis protocol for the conversion of heteroylthiosemicarbazides and 2,3‐dichloro‐1,4‐naphthoquinone to naphtho[2,3‐d]thiazoles, naphtho[2,3‐e][1,3,4]thiadiazines as well as bis(naphtho[2,3‐d]thiazolyl)copper(II) derivatives is described. The products were conclusively confirmed by single crystal X‐ray analyses. A mechanism for the formation of the products is presented.     

Hypervalent Iodine(III) Mediated Synthesis of 2‐Substituted‐5‐Aryloxazoles

A direct and efficient method for the preparation of 2‐substituted‐5‐aryloxazoles was realized by reaction of aryl methyl ketones with various nitriles in the presence of phenyliodine(III) triflate.     

One‐pot Synthesis of Tetrahydrobenzo[b]pyrans Catalyzed by PEG‐1000 Bridged Primary Amine Functionalized Dicationic Ionic Liquid in Water

A novel poly (ethylene glycol) bridged primary amine functionalized dicationic ionic liquid ([PA‐PEG₁₀₀₀‐DIL][BF₄]) was synthesized and characterized by ¹H‐NMR, ¹³C‐NMR, FT‐IR and ESI‐MS. The thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis indicated the high thermal stability of [PA‐PEG₁₀₀₀‐DIL][BF₄]. It was used as an efficient and recyclable catalyst for the synthesis of substituted tetrahydrobenzo[b]pyrans through a one‐pot three‐component condensation of aromatic aldehydes, malononitrile and dimedone in 86% ～ 96% yields within 10 ～ 30 min in water. This method offers several advantages such as mild reaction conditions, simple operation and environmental friendliness. Furthermore, the catalyst could be easily recovered and reused for at least five runs without obvious loss of catalytic activity.     

Synthesis,Structure and Biological Activities of Novel 2‐(Trifluoromethyl)‐ 6‐arylimidazo[2,1‐b][1,3,4]‐thiadiazole (bis‐)Mannich Base Derivatives Containing Substitutedpiperazine Moiety

A convenient and practicable method for the synthesis of the novel 2‐(trifluoromethyl)‐6‐arylimidazo[2,1‐b][1,3,4]‐thiadiazole (bis‐)Mannich base derivatives containing various substitutedpiperazine motif has been developed based on the fused‐heterocycle intermediate. The new structures were identified through melting points, ¹H NMR, ¹³C NMR, ¹⁹F NMR, elemental analysis (or HRMS) and X‐ray single‐crystal diffraction. The pesticidal bioassays showed that some of compounds exhibited good fungicidal activities against Cercospora arachidicola, Physalospora piricola and Rhizoctonia cereali at 50 mg/L; some of them displayed favourable insecticidal activities against oriental armyworm (Mythimna separata Walker) at 200 mg/L, particularly, Vk and Vm with mortality rate of 75% and 80% respectively, could be considered as new insecticidal lead compounds for further structural optimization.     

Hypervalent Iodine in the Synthesis of Bridgehead Heterocycles: A Facile Route to the Synthesis of 6‐Arylimidazo[2,1‐b]thiazoles Using [Hydroxy(tosyloxy)iodo]benzene

α‐Tosyloxyketones (2), readily accessible through hypervalent iodine oxidation of enolizable ketones (1) using [hydroxy(tosyloxy)iodo]benzene (HTIB) in acetonitrile, exclusively generates the 6‐arylimidazo[2,1‐b]thiazoles (4) on treatment with commercially available 2‐aminothiazole (3).     

Synthesis of New Furo[3,4‐b]quinolin‐1(3H)‐one Scaffolds Derived from γ‐Lactone‐Fused Quinolin‐4(1H)‐ones

In the context of our aim of discovering new antitumor drugs among synthetic γ‐lactone‐ and γ‐lactam‐fused 1‐methylquinolin‐4(1H)‐ones, we developed a rapid access to 5‐methyl‐1,3‐dioxolo[4,5‐g]furo[3,4‐b]quinoline‐8,9(5H,6H)‐dione ( 9 ) exploiting the γ‐lactone‐fused chloroquinoline 10 previously synthesized in our laboratory (Scheme 1). We also elaborated efficient synthetic methods allowing for a rapid access to two nonclassical bioisosteres of 9 , i.e., a deoxy and a carba analogue. The deoxy analogue 11 was prepared in two steps from the γ‐lactone‐fused quinoline 13 which was also the synthetic precursor of 10 (Scheme 1). The carba analogue 6,9‐dihydro‐5‐methyl‐9‐methylene‐1,3‐dioxolo[4,5‐g]furo[3,4‐b]quinolin‐8(5H)‐one ( 12 ) was easily prepared by HCl elimination from the 9‐(chloromethyl)dioxolofuroquinoline 15 , which was obtained via a three‐component one‐pot reaction from N‐methyl‐3,4‐(methylenedioxy)aniline (=N‐methyl‐1,3‐benzodioxol‐5‐amine; 16 ), commercially available chloroacetaldehyde, and tetronic acid ( 17 ) (Scheme 2).     

Synthesis of Novel 1H‐Imidazol[1,2‐a]Indeno[2,1‐e]Pyridine‐6(5H)‐Ones Derivatives via a One‐Pot Four‐Component Condensation Reaction

1H‐imidazol[1,2‐a]indeno[2,1‐e]pyridine‐6(5H)‐ones derivatives were synthesized in a one‐pot four‐component condensation of corresponding aldehydes, 1,3‐indandione, diamine, and nitro ketene dithioacetal using KAl(SO₄)₂·12H₂O (alum) as nontoxic, reusable, inexpensive and easily available catalyst in good to excellent yields. This green protocol provides a powerful entry into fused polycyclic structures related to bioactive heterocycles.     

Synthesis of 2H‐Indazolo[2,1‐b]Phthalazine‐1,6,11(13H)‐Trione Derivatives Using Wet Cyanuric Chloride under Solvent‐Free Condition

A simple and facile synthesis of 2H‐indazolo[2,1‐b]phthalazine‐1,6,11(13H)‐trione derivatives has been accomplished by a three‐component condensation reaction of dimedone, aromatic aldehydes and phthalhydrazide under solvent‐free conditions in the presence of wet cyanuric chloride as a catalyst.     

Synthesis and Biological Activities of 7‐Arylazo‐7H‐pyrazolo[5,1‐c][1,2,4] Triazol‐6(5H)‐Ones and 7‐Arylhydrazono‐7H‐[1,2,4]triazolo[3,4‐b] [1,3,4]thiadiazines

Two series of 7‐arylazo‐7H‐3‐(2‐methyl‐1H‐indol‐3‐yl)pyrazolo[5,1‐c][1,2,4]triazol‐6(5H)‐ones 4 and 7‐arylhydrazono‐7H‐3‐(2‐methyl‐1H‐indol‐3‐yl)‐[1,2,4]triazolo[3,4‐b][1,3,4]thiadiazines 7 were prepared via reactions of 4‐amino‐3‐mercapto‐5‐(2‐methyl‐1H‐indol‐3‐yl)‐1,2,4‐triazole 1 with ethyl arylhydrazono‐chloroacetate 2 and N‐aryl‐2‐oxoalkanehydrazonoyl halides 5 , respectively. A possible mechanism is proposed to account for the formation of the products. The biological activity of some of these products was also evaluated.