To gain a deeper understanding of the formation of the synthetically important 3,6‐dihydro‐2H‐1,2‐oxazines, the 6‐endo‐trig cyclization of allenyl‐substituted hydroxylamines was experimentally investigated in detail employing a model compound. The solvent effect was moderate with respect to the rate, but crucial to suppress side‐product formation. Surprisingly, acids or bases had no big influence on

Oxindole units were common structure features of natural products and drugs. A novel method for synthesizing 2‐oxindoles from 1,3‐dicarbonyl compounds based on ferrous salt and iodide catalyst was described. Using Fe(OAc) 2 /NaI/Na 2 S 2 O 8 , various 2‐alkyl‐3‐phenylamino‐3‐oxopropanoates bearing fluoro, chloro, bromo, alkyl, alkoxy, trifluoromethyl, cyano etc . on the benzene ring were converted

The synthesis of fused bicyclic oxazolidin‐2‐one (OZO) iminosugars was achieved through a tandem Staudinger reduction/retro‐Michael/intramolecular Michael addition from the corresponding OZO azidosugars. Those precursors, based on both aldopentofuranoses and ketofuranohexoses backbones, were obtained following alkylation and oxidation of the related oxazolidine‐2‐thione (OZT) azidosugars. Eight OZO

Ajudazol B is a polyketide secondary metabolite, isolated from the myxobacterium Chondromyces crocatus , that exhibits potent biological activity. Here we report a convergent total synthesis of 8‐epi‐(‐)‐ajudazol B. The key step is a regio‐selective alkylation and oxidative rearrangement of a reactive isobenzofuran intermediate that generates the isochromanone core. This approach provides a fast and

An oxidative functionalization of cyclopentanones or cyclohexanones with simple alcohols was first demonstrated, affording a series of 2‐alkoxycyclopent‐2‐en‐1‐ones or 2‐alkoxycyclohex‐2‐en‐1‐ones in moderate to excellent yields. The reaction was involved in tandem iodization, substitution, oxidation and addition‐elimination processes in one pot. This method is highly atom‐economical and operationally

A simple and convenient method has been developed for the synthesis of 3‐(arylthio)imidazo[1,2‐ a ]pyridin‐2(3H)‐ones via a catalyst‐free reaction of 2‐aminopyridinium bromides with sodium arenesulfinates. A variety of 3‐(arylthio)imidazo[1,2‐ a ]pyridin‐2(3H)‐ones were obtained in moderate to excellent (33‐85%) yields. The developed protocol is operationally simple, exhibits a broad substrate scope

The reactions of 4,4‐dichloro‐1,2‐diazabuta‐1,3‐dienes with dimethyl malonate, cyanoacetic esters and ethyl acetoacetate provided straightforward access to highly functionalized pyridazine derivatives. The approach was found very general for the highly efficient synthesis of various pyridazine derivatives which can be isolated in moderate to excellent yields. The possibility of their subsequent functionalization

In the original article,1 one of the palladium catalyst loading amounts in the Scheme 1 was incorrectly cited. Reinvestigation of the reaction condition in reference 6b evidenced that the catalytic amount of [Pd(Phen)2][BF4]2 for the first reaction formula in Scheme 1 is 1.0 mol‐% not 10 mol‐%. The amended version of Scheme 1 is reported below: Scheme 1 Open in figure viewerPowerPoint Reported and

The present review describes the methods reported for the synthesis of 3(2 H )‐furanones. This heterocycle forms the core structure of a number of natural products and biologically active scaffolds. We have covered all reports available on the synthesis of 3(2 H )‐furanone derivatives and have divided the review into several sections based on the substitution patterns present in the heterocycle. Special

During the synthesis of 1,10‐phenanthroline derivatives sterically hindered in the 2 and/or 9 positions, serendipity led to the discovery of a new substitution pattern on phenanthroline with good and reproducible yields. When toluene was used as a solvent and the aryl‐lithio reagents generated with tBuLi, after a first substitution at the 2 position, a benzyl substituent was regioselectively introduced

Axial rich glycosyl donors often display superior reactivity and stereoselectivity in glycosylations. In this study, a glucosamine glycosyl donor locked in a 1 C 4 conformation using a six‐membered carbamate ring, i.e. an oxazinone, is synthesized and studied. The 2 N ,4 O carbamate is synthesized in one step from the corresponding azide. The glycosylation properties was studied by glycosylating different

We herein report an unprecedented strategy for the asymmetric α‐chlorination of β‐ketoesters with hypervalent iodine‐based Cl‐transfer reagents using simple Cinchona alkaloid catalysts. Our investigations support an α‐chlorination mechanism where the Cinchona species serves as a nucleophilic catalyst by reacting with the chlorinating agent to generate a chiral electrophilic Cl‐transfer reagent in situ

Bench‐stable meso‐substituted [20]π‐ dibenzihomoporphyrins were synthesized through acid‐catalyzed condensation of dipyrrole derivatives with aryl aldehydes. The insertion of a 1,1,2,2‐tetraphenylethene (TPE) or but‐2‐ene‐2,3‐diyldibenzene unit in the porphyrin framework results in the formation of [20π]‐dibenzihomoporphyrins, merging the features of hydrocarbons and porphyrins. Single crystal X‐ray

Gold(III) coordination of new chiral polydentate ( N,)N,O ‐pyridine based ligands is reported. Successful coordination afforded novel chiral N,N,O ‐tridentate Au(III) complexes with the 2‐pyridyl‐6‐( 1S,2S,5R )‐neomenthol‐1‐yl)‐pyridine ligand ( 1 H, 13 C, 15 N NMR, HRMS, IR, XRD). The chiral 2‐aryl‐6‐alkylpyridine alcohol ligands were prepared from 2,6‐dibromopyridine by initial stereoselective addition

Its even more than a centennial that the systematic researches of chemical alteration of sugars have been advancing. Out of all the interest in the field of N ‐glycoside has assembled pace over the past few years. Therefore, N ‐functionalization of sugar is one of the most fundamental modifications along with other group like azide, amide etc also play a remarkable role in the field of glycoscience

The method of direct reductive amination of camphor and fenchone was proposed. The most effective reducing agent is iron carbonyl. No ligands or solvents are needed. The stereochemistry of the corresponding products was determined by HMBC, HSQC, and NOESY spectra. The limitations of the method were shown. The reaction of camphor with primary amines led to exclusively exo product, while the reaction

Sialic acids, a ubiquitous family of sugars shown to be involved in numerous biologically important processes, exhibit remarkable structural diversity in nature. Access to these derivatives by chemical and enzymatic means is a major bottle neck in understanding the role played by each particular modification. As part of a program to study such roles and determine the substrate specificity of novel

A straightforward and convenient route has been developed for the synthesis of 3‐unsubstituted phthalide derivatives from aryl amides and paraformaldehyde by ruthenium(II)‐catalyzed C‐H activation. The reaction proceeds through tandem ortho‐hydroxymethylation of aryl amide and subsequent intramolecular lactonization.