Isocyanide-based multicomponent reactions: synthesis of 3,3-dicyano-N-alkyl-2-arylpropanamide derivatives

A new isocyanide-based multicomponent reaction between an aromatic aldehyde, malononitrile, an isocyanide, and acetic acid efficiently provides 3,3-dicyano-N-alkyl-2-arylpropanamide derivatives in excellent yields in ethanol at 70 °C. This reaction led to the construction of two carbon-carbon bonds and one amide group in a single synthetic step.     

Palladium-catalyzed amination in the synthesis of macrocyclic compounds containing 1,3-disubstituted adamantane fragments

Palladium-catalyzed amination of 1,3-dibromobenzene, 2,6-dibromopyridine, 3,3′-dibromobiphenyl, 2,7-dibromonaphthalene, and 1,8-dichloroanthracene with an equimolar amount of 2,2′-(adamantane-1,3-diyl)diethanamine resulted in the formation of macrocyclic compounds containing one or several adamantane and one or several aromatic fragments. The reactions of 2,2′-(adamantane-1,3-diyl)diethanamine with excess 1,3-dibromobenzene, 2,6-dibromopyridine, 1,8-dichloroanthracene, and 1,8-dichloroanthraquinone gave the corresponding N,N′-diaryl derivatives. Polyaza macrocycles incorporating adamantane, aromatic, and 4,7,10-trioxatridecane-1,13-diamine fragments, were obtained by palladium-catalyzed amination of the N,N′-diaryl derivatives with 4,7,10-trioxatridecane-1,13-diamine.     

Synthetic application of 3,3-dichloro-1,1,1-trifluoroacetone (DCTFA) and 3,3,3-trichloro-1,1,1-trifluoroacetone (TCTFA) for trifluorolactic acid derivatives

Synthetic application of 3,3-dichloro-1,1,1-trifluoroacetone (DCTFA) and 3,3,3-trichloro-1,1,1-trifluoroacetone (TCTFA) for industrially important trifluorolactic acid derivatives is described. Trifluorolactic acid was obtained by hydrolysis of DCTFA under basic conditions. On the other hand, α-substituted trifluorolactic acid derivatives, such as α-methyltrifluorolactic acid and Mosher’s acid, were obtained by addition reaction between TCTFA and carbon nucleophiles, followed by subsequent transformation of trichloromethyl group.     

1,1′-Methylene-bis(1,1′,2,2′,3,3′,4,4′-octahydroisoquinoline): synthesis, reaction, resolution, and application in catalytic enantioselective transformations

The preparation of new chiral 1,3-diamine ligand systems based on the 1,1′-methylene-bis(1,1′,2,2′,3,3′,4,4′-octahydroisoquinoline) framework is described. Synthesis of various mono-, di-, and bridged N-alkyl derivatives are presented. Resolution of one compound, its Cu(I)Br X-ray crystallographic structure and the preliminary results on its application in the enantioselective Henry and Aldol reactions are disclosed.     

One-pot synthesis of 1,2,4,5-tetrahydro-2,4-dioxobenzo[b][1,4]diazepine and malonamide derivatives using multi-component reactions

In this work, a new series of 1,2,4,5-tetrahydro-2,4-dioxobenzo[b][1,4]diazepine and malonamide derivatives have been synthesized using an aromatic 1,2-diamine, Meldrum's acid, an isocyanide, and an arylidene malononitrile (or an aldehyde and malononitrile instead of an arylidene malononitrile) in CH₂Cl₂ at ambient temperature. Synthesis of 1,2,4,5-tetrahydro-2,4-dioxobenzo[b][1,4]diazepine proceeded via four- and five-component reactions; while the synthesis of malonamide derivatives was performed using five- and six-component reactions. In addition, a new series of the malonamide derivatives have been prepared using an aldehyde, malononitrile, Meldrum's acid, an isocyanide, and two molecules of 1,4-diamine via a six-component reaction. These procedures provide alternative methods to the synthesis of a new series of 1,2,4,5-tetrahydro-2,4-dioxobenzo[b][1,4]diazepine and malonamide derivatives.     

钯催化烯丙基磺酰胺的分子内胺氟化反应

报道了钯催化的非活性烯烃的胺氟化反应,在酸性添加剂HOAc的作用下,反应以较好的收率和区域选择性地得到6-endo环合产物,实现了氟代的环状磺胺类产物的有效合成.     

Short synthesis of diamide-linked sucrose macrocycles

A convenient route to macrocyclic diamide-linked macrocyclic derivatives with a sucrose scaffold is presented. Reaction of sucrose based amines (o- and m-) with acid dichlorides afforded the monomeric macrocycles in excellent yields, while reaction of the p-amines also provided dimeric products.     

A novel one-pot synthesis of 1,2,4-triazole-3,5-diamine derivatives from isothiocyanates and mono-substituted hydrazines

1,2,4-Triazole-3,5-diamine derivatives were synthesized in moderate to high yields in one-pot reaction from the corresponding isothiocyanates, mono-substituted hydrazines, and sodium hydrogencyanamide, in the presence of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride. Typically, two target compounds were obtained, but high regioselectivities to one isomer were observed when aromatic and sterically bulky hydrazines were used. A number of examples with a detailed representative procedure are given.     

Cascade Transformations of (2,2-Diaryl-3,3-dichloroaziridin-1-yl)acetates

Esters of (2,2-diaryl-3,3-dichloroaziridin-1-yl)acetic acid prepared from glycine derivatives under alkylation conditions afford esters of 2-[N-alkyl-N-(2,2-diaryl-1-cyanovinyl)amino]-3,3-diarylacrylic acid in 20-40% yield. The reaction resulting in these compounds proceeds through a cascade of 3-chloro-2-azadiene and ylide intermediates. 3-Chloro-2-azadienes originating from (2,2-diaryl-3,3-dichloroaziridin-1-yl)acetates react with primary and secondary amines at the carbon atom of imine group providing ketenimines which undergo ketenimine-nitrile rearrangement or fragmentation. The other bases (KOH, MeONa, DBU) effect dehydrochlorination of the mentioned 3-chloro-2-azadienes giving nitrile-ylides which are trapped by nucleophilic reagents. The 3-chloro-2-azadiene obtained from methyl (2,2-diaryl-3,3-dichloroaziridin-1-yl)acetate and DBU was relatively stable and was isolated as an individual compound. (2,2-diaryl-3,3-dichloroaziridin-1-yl)propionates behave as nonfunctionalized dichloroaziridines.     

Synthesis of a new hetrocyclic system 7,8-dihydroimidazo[1,2-<Emphasis Type="Italic">c</Emphasis>][1,3]oxazolo[4,5-<Emphasis Type="Italic">e</Emphasis>]pyrimidine

2-(Acylaminocyanomethylene)imidazolidines are formed on interacting 2-acylamino-3,3-dichloro-acrylonitriles with ethylenediamine. The former are converted into new derivatives of oxazolo-[4,5-e]pyrimidine on treatment with trifluoroacetic acid, and then with triethyl orthoformate.     

A powerful method to prepare sulfur-rich macrocycles

Various cyclic polysulfanes (up to a 16-membered ring) have been selectively obtained from the corresponding disubstituted trityl-protected polysulfane benzene derivatives upon treatment with elemental iodine in the presence of silica gel. Depending on the position of the sulfur-rich moieties and the presence of a methylene linker between the benzene ring and sulfur atoms, two types of products containing either one or two benzene subunits have been isolated. The scope of the reaction, its selectivity, and mechanism are discussed.     

Highly enantioselective fluorescent recognition of mandelic acid derivatives by chiral salen macrocycles

Calixarene-like chiral salen macrocycles can be used for the enantioselective fluorescent recognition of mandelic acid derivatives. It was observed that one enantiomer of mandelic acid causes a 28-fold increase in the fluorescence intensity of a chiral salen macrocycle, whereas the other enantiomer causes only a 14-fold fluorescence enhancement. This highly enantioselective fluorescent response makes chiral salen macrocycles useful for the enantioselective fluorescent recognition of some mandelic acid derivatives.     

Alpha-glucosidase inhibitors ellagic acid derivatives with immunoinhibitory properties from Terminalia superba

Fractionation of stem barks of Terminalia superba yielded two new ellagic acid derivatives, 3,4'-di-O-methylellagic acid 3'-O-beta-D-xylopyranoside (1) and 4'-O-galloy-3,3'-di-O-methylellagic acid 4-O-beta-D-xylopyranoside (2) together with known 3,3'-di-O-methylellagic acid, ellagic acid and 3,3'-di-O-methylellagic acid 4'-O-beta-D-xylopyranoside. Compounds (1) and (2) showed significant alpha-glucosidase inhibition activity and possessed significant immunoinhibitory activities with no cytotoxic effects.     

Substituted 4(5H)-oxazolones and their salts. 3. Synthesis of 4(5H)-oxazolonium salts from amides of 2,4-dihydroxy-3,3-dimethylbutanoic acid

2-Alkyl-substituted 4(5H)-oxazolonium salts were synthesized by the reaction of amides of 2,4-dihydroxy-3,3-dimethylbutanoic (pantoic) acid with aliphatic carboxylic acid anhydrides in the presence of an equimolar amount of perchloric acid. The hydrolysis of these salts was realized. Various acyl derivatives of pantoic acid amides were obtained, and the possibility of their cyclization to give 4(5H)-oxazolonium salts under the influence of condensing reagents was demonstrated. The mechanism of the heterocyclization of pantoic acid amides is discussed on the basis of these results.See [1] for communication 2.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 894–900, July, 1981.     

Enantioselective oxidative coupling of methyl 3-hydroxy-2-naphthoate using mono-N-alkylated octahydrobinaphthyl-2,2′-diamine ligand

Mono-N-alkylated octahydrobinaphthyl-2,2′-diamine (H₈-BINAM) chiral ligands were employed in the catalytic and asymmetric oxidative coupling of methyl 3-hydroxy-2-naphthoate to the corresponding binaphthol derivative. The diamine ligand with one N-(3-pentyl) group shows highest enantioselectivity in the biaryl coupling among other BINAM derivatives, and the coupling reaction proceeds faster than the reactions using alkanediamine ligands.     

Oxiranes in the Ritter Reaction. Synthesis of 6,7- and 5,8-Dimethoxy-3,3-dialkyl-3,4-dihydroisoquinolines by a Tandem Alkylation-Cyclization Reaction

The interaction of 1,2- or 1,4-dimethoxybenzene with isobutylene oxide and nitriles RCN leads to 1-R-6,7- or 1-R-5,8-dimethoxy-3,3-dimethyl-3,4-dihydroisoquinolines. In the case of 1,2-dimethoxybenzene and cyclohexene oxide the similar reaction is accompanied by rearrangement and 1-R-3,3-tetramethylene-3,4-dihydroisoquinolines are formed in low yield. On using cyanoacetic acid ester and any oxide derivatives of tetrahydroisoquinolylideneacetic acid are formed.     

Chemical constituents with antibacterial activity from Euphorbia sororia

A group of ceramide (1) was isolated from the aerial parts of Euphorbia sororia. On the basis of spectroscopic data, chemical methods and GC-MS analysis, the structure of 1 was characterised as (2S,3S,4R,8E)-2-(eicosanoyl approximately octacosanoyl amino)-1,3,4-octadecanetriol-8-ene. In addition, four known ellagic acid derivatives 3,3'-di-O-methylellagic acid (2), 3,3',4'-tri-O-methylellagic acid (3), 4-O-sulfooxy-3,3'-di-O-methylellagic acid (4) and 4-O-sulfooxy- 3,3',4'-tri-O-methylellagic acid (5) were isolated from the plant. Biological screening of all compounds revealed moderate antibacterial activity.     

Palladium-Catalyzed Cascade C−H Functionalization/Asymmetric Allylation Reaction of Aryl α-Diazoamides and Allenes: Lewis Acid Makes a Difference

A Pd-catalyzed cascade C−H functionalization/asymmetric allylation reaction with aryl α-diazoamides and allenes has been developed. The reaction provides an efficient approach to construct chiral 3,3-disubstituted oxindole derivatives in high levels of yield and enantioselectivity (up to 93 % ee). Notably, the chromium complex works as Lewis acid to facilitate the formation of palladium carbene and to enhance acidity of carboxylic acid, allowing for higher stereochemical control and efficiency.     

Novel perfluoroalkenylphosphonates and iodoperfluoroalkenes from 3,3 -bis (trifluoromethyl) -1,1,2,4,4,4-hexafluoro-1-butylene and nonafluoro-n-butoxy-1,1,2-trifluoroethylene

The reaction of 3,3-bis(trifluoromethyl)-1,1,2,4,4,4-hexafluoro-1-butylene and nonafluoro-n-butoxy-1,1,2-trifluoroethylene with tris(trimethylsilyl)phosphite gave fluorotrimethylsilane and the respective (Z)-alkenylbis(trimethylsilyl)phosphonates. In one case hydrolysis afforded the free phosphonic acid (CF₃)₃CCF = CFP(O) (OH)₂. Using tri-n-butylphosphine and boron trifluoride etherate, 3,3-bis(trifluoromethyl)-1,1,2,4,4,4-hexafluoro-1-butylene and nonafluoro-n-butoxy-1,1,2-trifluoroethylene were converted into the corresponding phosphonium tetrafluoroborates, which when reacted further with iodine in the presence of Na₂CO₃ gave the iodo derivatives (CF₃)₃CCF = CFI and C₄F₉OCF = CFI.     

Catalytic,asymmetric Mannich-type reactions of alpha-imino esters bearing readily removable substituents on nitrogen

[reaction: see text] Catalytic, enantioselective Mannich-type reactions of alpha-imino esters bearing readily removable substituents on nitrogen are described. Several N-carbamate-protected alpha-imino esters, which are readily prepared from 2-bromoglycine esters using a polymer-supported amine, reacted with silicon enolates to afford the desired adducts in high yields with high enantioselectivity using a copper(II)-diamine complex. Easy deprotection of the product amine and transformation to free alpha-amino acid derivatives have also been demonstrated.