Azomethine ylide mediated inversion of configuration of quaternary imidazoline carbon: converting trans- to its cis- imidazolines

An efficient synthetic methodology of converting trans-4,5-diaryl-2-imidazolines to the corresponding cis-4,5-diaryl-2-imidazolines has been developed. This methodology features mild reaction conditions and a simple one-pot two-step procedure.     

Efficient microwave-assisted direct C-benzoylation of phenols and naphthols with benzoic acid catalyzed by bismuth triflate under solvent-free or ionic liquid conditions

An efficient and simple route for the synthesis of ortho-hydroxyaryl ketones has been developed. The microwave-assisted direct C-benzoylation of phenols and naphthols in the presence of metal triflates afforded the corresponding ortho-hydroxyaryl ketones in moderate to excellent yields. Bismuth triflate showed the best catalytic performance compared to other metal triflates. The protocol has advantages including short reaction times, high chemoselectivity towards C-acylation, and simple work-up. Additionally, bismuth triflate can be easily recovered and reused several times without significant loss of catalytic performance.     

Highly selective methanesulfonic acid-catalyzed 1,3-isomerization of allylic alcohols

Secondary and tertiary allylic alcohols undergo 1,3-isomerization smoothly in the presence of methanesulfonic acid under simple and efficient conditions to afford selectively the corresponding primary E-allylic alcohols in excellent yields.     

A practical and inexpensive ‘convertible’ isonitrile for use in multicomponent reactions

N-tert-Butylamides are readily converted into the corresponding carboxylic acids by simple nitrosation. The process, which occurs under mild nonaqueous conditions, leaves carboxylic esters untouched and transforms multicomponent reaction products into useful building blocks for further synthetic elaboration.     

Hydrosiloxane-Ti(OiPr)4: an efficient system for the reduction of primary amides into primary amines as their hydrochloride salts

A simple and useful method for the reduction of primary amides into the corresponding amines using a polymethylhydrosiloxane (PMHS)-Ti(OiPr)₄ reducing system is described. Aromatic as well as aliphatic primary amides are reduced in high selectivity and excellent yields. The reduction could proceed via dehydration of the primary amide group into the corresponding nitrile which is then reduced into the corresponding primary amine.     

Regio- and stereoselective hydrohalogenation of ynamide components in 1,3-butadiynes with in situ generated HX

A simple protocol for regio-, and stereoselective hydrohalogenation of ynamide moieties in 1,3-butadiyne structures is described. The facile approach enables exact syn-addition of HX to the diyne components, giving just single isomer of the corresponding dienes and enynes.     

Sulfamic acid: an efficient, cost-effective and recyclable solid acid catalyst for the Friedlander quinoline synthesis

o-Aminoaryl ketones undergo smooth condensation with α-methylene ketones in the presence of sulfamic acid (NH₂SO₃H) (SA) under mild reaction conditions to afford the corresponding polysubstituted quinolines in excellent yields. The catalyst can be recovered by simple filtration and can be recycled in subsequent reactions. The method is simple, cost-effective and environmentally benign.     

A straight forward and first total synthesis of Penilumamides B–D

A simple and straight forward first total synthesis of rare lumazine peptides, Penilumamide B, C and D isolated from the marine-derived fungi Aspergillus and Penicillium sp. is described from a common starting material, 1,3-dimethyllumazine-6-carboxylic acid. Penilumamide C was prepared from Penilumamide B by oxidation of the methionine residue to the corresponding sulphone.     

Reactions of enaminones and related compounds with N,N-dimethylacetamide dimethyl acetal. A simple one-pot metal-free synthesis of polysubstituted benzene derivatives

Herein a simple one-pot metal-free synthesis of alkyl-, aryl-, heteroaryl- and alkoxycarbonyl substituted 1,3-bis(dimethylamino)benzene derivatives is described. The products were prepared from the corresponding methyl ketones or compounds with an α-methylene group in regard to the carbonyl group, using N,N-dimethylacetamide dimethyl acetal (DMADMA) as the reagent.     

Regioselective addition of 1,3-dicarbonyl dianion to N-sulfonyl aldimines: an expedient route to N-sulfonyl piperidines and N-sulfonyl azetidines

A simple route for the synthesis of δ-amino-β-keto esters and δ-amino-β-diketones is reported. This involves regioselective addition of 1,3-dianions derived from ethyl acetoacetate and acetyl acetone to N-sulfonyl aldimines. The δ-amino-β-keto ester derivatives were further converted into the corresponding N-sulfonyl piperidines and N-sulfonyl azetidines.     

A chemoselective deoxygenation of N-oxides by sodium borohydride-Raney nickel in water

A simple and convenient protocol for deoxygenation of aliphatic and aromatic N-oxides to the corresponding amines in good to excellent yield using sodium borohydride-Raney nickel in water is reported. Other functional moieties such as alkenes, halides, ethers, and amides are unaffected under the present reaction condition.     

nBu4NI-catalyzed oxidative amidation of aldehydes with tertiary amines

An efficient oxidative coupling protocol for amide formation has been developed. Various tertiary amines and aromatic aldehydes were oxidized to their corresponding tertiary amides in moderate to good yields in the presence of a simple nBu₄NI-catalyst.     

Sulfonylamidation of alkylbenzenes at benzylic position with p-toluenesulfonamide and 1,3-diiodo-5,5-dimethylhydantoin

Treatment of alkylbenzenes with p-toluenesulfonamide and 1,3-diiodo-5,5-dimethylhydantoin (DIH) in a small amount of carbon tetrachloride at 60 °C gave the corresponding α-p-toluenesulfonylamido)alkylbenzenes in good to moderate yields. The present reaction is a simple method for the α-sulfonylamidation of the benzylic position in alkylbenzenes.     

A simple algorithm for the construction of genealogical spin functions

A simple algorithm is given for the construction of spin eigenfunctions according to the genealogical scheme. The method can deal directly with the N-electron problem without any knowledge of the (N-1)-electron spin eigenfunctions. It uses the representation matrices corresponding to the transpositions (k,k + 1), the latter can be written down from the knowledge of the Young tableaux.     

Pallado-catalysed P-arylations and P-vinylation of 2-hydrogeno-2-oxo-1,4,2-oxazaphosphinanes

A simple and effective preparation of 2-aryl- (or 2-vinyl)-1,4,2-oxazaphosphinanes, phosphorus analogues of aryl-morpholinols has been developed, involving palladium catalysed coupling of aryl (or vinyl)-halides with 2-H-1,4,2-oxazaphosphinane in presence of triethylamine. A deprotection step was also proposed to afford the corresponding P-aryl-α-aminobenzylphosphinic acid.     

A novel synthetic approach to 4-acetamido-1-arylindazoles via Semmler–Wolff rearrangement of 1-aryl-6,7-dihydro-5H-indazol-4-one oxime

A simple and efficient procedure for the syntheses of 4-acetamido-1-arylindazoles from corresponding 1-aryl-6,7-dihydro-5H-indazol-4-one oximes by Semmler–Wolff aromatization using acetic anhydride and sodium iodide is reported.     

Fast, easy, solvent-free, microwave-promoted Michael addition of anilines to α,β-unsaturated alkenes: synthesis of N-aryl functionalized β-amino esters and acids

The rapid, simple, microwave-promoted synthesis of N-aryl functionalized β-amino esters using Michael addition reactions is presented. Reactions are performed neat at 200 °C for 20 min and are catalyzed by acetic acid. The esters can be easily hydrolyzed to the corresponding N-aryl functionalized β-amino acids.     

Lanthanide(III) nosylates as new nitration catalysts

Lanthanide(III) nosylates are novel, recyclable catalysts prepared from the noncorrosive and inexpensive p-nitrotoluenesulfonic acid and the corresponding lanthanide(III) oxide. With 5-10% catalyst loading, atom economic nitration of simple aromatic compounds was achieved in good to high yields.     

A simple rhodium-catalyzed addition reaction of aldehydes with arylboronic acids in aqueous γ-valerolactone

A simple rhodium-catalyzed addition reaction of aldehydes with arylboronic acids in aqueous γ-valerolactone provides the corresponding benzylic alcohols in moderate to good yields. Other organoboron reagents (boronic esters, aryl-trifluoroborates, etc.) also showed good compatibilities, albeit with relatively lower yields.     

Synthesis of Xanthones,Thioxanthones and Acridones by a Metal-Free Photocatalytic Oxidation Using Visible Light and Molecular Oxygen

9H-Xanthenes, 9H-thioxanthenes and 9,10-dihydroacridines can be easily oxidized to the corresponding xanthones, thioxanthones and acridones, respectively, by a simple photo-oxidation procedure carried out using molecular oxygen as oxidant under the irradiation of visible blue light and in the presence of riboflavin tetraacetate as a metal-free photocatalyst. The obtained yields are high or quantitative.