Highly Efficient One-Pot Synthesis of 2-Aminobenzoxazoles Using Triflic Acid as a Cyclodesulfurizing Reagent

An efficient one-pot synthetic strategy for 2-aminobenzoxazoles was developed from isothiocyanates and 2-aminophenol using triflic acid as a cyclodesulfurizing reagent.

Improved Synthesis of Monoprotected 5- and 6-Amino-2-azanorbornanes

An improved synthesis of Boc-monoprotected 5- and 6-amino-2-azanorbornanes is reported. The synthetic scheme consists of five steps and allows multigram quantities of the title compounds to be obtained. The regio- and stereochemistries of the products are established by two-dimensional NMR experiments.

Deoxygenation of Aromatic Ketones Using Transfer Hydrogenolysis with Raney Nickel in 2-Propanol

Aryl ketones are readily deoxygenated to their corresponding aryl alkanes upon treatment with Raney nickel catalyst in boiling 2-propanol.

Simple and Efficient One-Pot Synthesis of Nitriles from Amides and Oximes Using in Situ–Generated Burgess-Type Reagent

The dehydration of aldoximes and amides, and oxidation of benzoin are accomplished in one-pot using in situ–generated Burgess-type reagent.

Facile and Efficient Method for the Synthesis of 14-Substituted-14-H-dibenzo[a,j]xanthenes Catalyzed by Ruthenium Chloride Hydrate as a Homogeneous Catalyst

Synthesis of dibenzoxanthenes through condensation of β-naphthol with various aromatic and aliphatic aldehydes in ethanol as an ecofriendly solvent using Ru^III as catalyst is reported.

Novel Synthetic Routes of 3-Methoxypropanal from Glycerol

A new synthesis of 3-methoxypropanal from glycerol was presented. With this new approach, the conversion of glycerol to 3-methoxypropanal can be effected in moderate yield using catalysts of copper sulfate and polyethylene glycol (PEG).

Copper(I)-Catalyzed Cycloaddition of Methyl O-Propargylpodocarpate and Azides at Room Temperature

Copper iodide was employed as an efficient catalyst for the synthesis of 1,2,3-triazole derivatives of podocarpic acid at room temperature through “click” chemistry cycloaddition reactions of methyl O-propargylpodocarpate and propargyl O-propargylpodocarpate with azides.

Synthesis of 4-Methylene-1,3-naphthoxazines by the Reaction of Imines with Triphosgene

Reaction of 2-acetyl-1-naphthol with aliphatic amines under microwave irradiation gave the corresponding imines (Schiff bases), which were treated with triphosgene to give 4-methylene-1,3-naphthoxazines in good yields.

Stereoselective Synthesis of Dialkyl 2-(Arylsulfonylamino)-3-(dialkoxyphosphoryl) Succinates by Reaction of Trialkyl(aryl) Phosphites,Dialkyl Acetylenedicarboxylates,and Arylsulfonamides

A three-component reaction of trialkyl(aryl) phosphites, dialkyl acetylenedicarboxylates, and arylsulfonamides is described as a simple and efficient route for the synthesis of dialkyl 2-(arylsulfonylamino)-3-(dialkoxyphosphoryl)-succinates in good yields.

Use of Magnesium (Turnings) as a Powerful Catalyst for the O-Acylative Cleavage of Tetrahydrofuran

In a short reaction time, acyl chlorides and dry tetrahydrofuran react in the presence of a catalytic amount of magnesium turnings (Mg) at 25 °C to give 4-chlorobutyl esters in excellent yields.

Efficient and Selective Demethylation of Heteroaryl Methyl Ethers in the Presence of Aryl Methyl Ethers

A new and efficient method for the demethylation of 6-membered aza-heterocyclic methyl ethers is described using lithium chloride and para-toluenesulfonic acid. This process is chemoselective for aza-heterocyclic methyl ethers in the presence of aryl methyl ethers.

Three-Component,One-Pot Synthesis of 2,4,5-Trisubstituted Imidazoles Catalyzed by TiCl4-SiO2 Under Conventional Heating Conditions or Microwave Irradiation

In this study, silica-supported titanium tetrachloride was prepared and used as a novel catalyst for rapid and efficient synthesis of 2,4,5-trisubstituted imidazoles by a three-component, one-pot condensation of 1,2-diketones and aryl aldehydes in excellent yield under solvent-free conditions using conventional heating or microwave irradiation.

Green and Practical Synthesis of Carbamates from Ureas and Organic Carbonates

A practical method for the synthesis of carbamates from ureas and organic carbonates was developed with 100% atom economy using La₂O₃/SiO₂ as catalyst without any additional solvent. The scope of the protocol is demonstrated in the synthesis of 14 carbamates with various functional groups in excellent yields (76–95%).

Recyclable Siloxy Serine Organocatalyst for the Direct Asymmetric Mannich Reactions in Ionic Liquids

A recyclable siloxy-L-serine organocatalyst has been developed to catalyze the asymmetric direct three-component Mannich reactions in ionic liquid hmim[PF₆], furnishing the β-amino carbonyl scaffold in high enantio- and diastereoselectivities. The direct Mannich reaction between a selection of aromatic aldehydes and ketones resulted in good yields and high enantioselectivities.

Ammonium Chloride–Catalyzed One-Pot Synthesis of Tetrahydrobenzo[α]xanthen-11-one Derivatives Under Solvent-Free Conditions

A one-pot, multicomponent reaction of aldehydes, dimedone, and β-naphthols is described for the preparation of 12-aryl- or 12-alkyl-8,9,10,12-tetrahydrobenzo[α]xanthen-11-one derivatives using ammonium chloride as a mild, inexpensive, and environmentally benign catalyst under solvent-free conditions. Different types of aldehyde and β-naphthol derivatives are used in the reaction, and in all cases the products were synthesized successfully.

Facile Synthesis of Spiro Oxindoles,Azaoxindoles, and Dihydroisoquinolone

Formation of 1-aryl-4-oxo-cyclohexa(e)nonecarboxylates from the Diels–Alder cycloaddition of 2-trimethylsilyloxy-1,3-butadiene and Danishefsky diene with aryl- and pyridylacrylates and further conversion thereof to spirocycles is described. This provides an efficient method for spiro oxindoles, azaoxindoles, and dihydroisoquinolones.

Palladium-Catalyzed N-Arylation of 3-Functionalized 2-Amino-4,5-dimethylpyrroles

A versatile class of 2-aminopyrroles containing various electron-withdrawing substituents at the 3-position have been N-arylated on the amine using a palladium-catalyzed cross-coupling reaction. Using this methodology, a pyrimidone-based tricyclic system has been prepared in just one step from a starting 2-aminopyrrole.

Amberlyst-15–Catalyzed Facile Synthesis of α-Amino Phosphonates

A simple and efficient method has been developed for the synthesis of sulfonamide phosphonates from N-tosyl aldimines and dimethyl trimethylsilyl phosphite at 0 °C in the presence of Amberlyst-15 as a heterogeneous catalyst.

Efficient Synthesis of 3-Substituted 1,2,4-Triazolo[4,3-a]pyridine by [Bis(Trifluroacetoxy)iodo]benzene-Catalyzed Oxidative Intramolecular Cyclization of Heterocyclic Hydrazones

A series of 1,2,4-triazolopyridines have been prepared by oxidative intramolecular cyclization of heterocyclic hydrazones with [bis(trifluroacetoxy)iodo]benzene. General applicability of this simple transformation was confirmed by synthesis of 1,2,4-triazolo[4,3-a]pyridine. The advantages of this protocol are the nontoxicity of catalyst and shorter reaction time to obtain good preparative yield.

Novel One-Pot Synthesis for 2,5-Diaryl and 5-Aryl-pyridazin-3(2H)-ones

A novel method for the synthesis of 2-phenyl-5-(o-hydroxyphenyl)-pyridazin-3(2H)-ones and 5-(o-hydroxyphenyl)-pyridazin-3(2H)-ones has been found during the reaction of 4-bromomethylcoumarins with phenylhydrazine and hydrazinehydrate, respectively, under controlled alkaline conditions.