This communication describes a metal-free methodology involving an efficient and controlled reduction of secondary amides to imines, aldehydes, amines in good excellent yields under ambient pressure temperature. The process includes chemoselective activation amide with triflic anhydride the presence 2-fluoropyridine. electrophilic activated can then be reduced corresponding iminium using triethylsilane, cheap, rather inert, commercially available reagent. Imines isolated after basic workup...

A copper-catalyzed amidation of allylic and benzylic C−H bonds with both primary secondary sulfonamides is described. The reaction applicable to the coupling a diverse set hydrocarbon species aryl, heteroaryl, alkyl tolerant variety functional groups. Mechanistic insight has been gained through isolation acetate intermediate, which was demonstrated undergo facile conversion substituted sulfonamide product under copper catalysis.

Imidazo[1,5-a]azines are synthesized in moderate to excellent yields using a mild cyclodehydration/aromatization reaction triggered by the use of triflic anhydride (Tf2O) and 2-methoxypyridine (2-MeOPyr). Various substitution patterns functional groups were found be compatible under optimized conditions. In addition, 5-bromo-3-aryl derivative was also shown active Sonogashira cross-coupling direct arylation reactions. A tertiary amide as substrate leading synthesis an...

We report a synthetic glycosylation reaction between sucrosyl acceptors and glycosyl fluoride donors to yield the derived trisaccharides. This proceeds at room temperature in an aqueous solvent mixture. Calcium salts tertiary amine base promote with high site-selectivity for either 3'-position or 1'-position of fructofuranoside unit. Because nonenzymatic oligosaccharide syntheses are underdeveloped, mechanistic studies were carried out order identify origin selectivity, which we hypothesized...

We report herein the three-step enantioselective synthesis of β-trifluoromethyl α-amino acids including trifluorovaline (TFV) using stereoselective hydrogenation with [((R)-trichickenfootphos)Rh(cod)]BF4 catalyst as key step.

An unprecedented intramolecular pyridine activation−asymmetric dearomatization reaction is described. This process produces 5-substituted indolizidines and 6-substituted quinolizidines in excellent yields a highly regio- diastereoselective fashion. Formal syntheses of trans-indolizidine alkaloids are presented along with some preliminary results the formation C-5 quaternary centers.

The discovery and optimization of a reaction between 2-chloropyridines 2H-azirines producing imidazo[1,2-a]pyridines is described. treatment with triflic anhydride (Tf2O) forms an electrophilic 1-trifloyl-aziridin-2-yl triflate species which, when reacted in situ 2-halopyridines, generates transient pyridinium salts. These salts were treated the same pot triethylamine (Et3N), leading to selective formation C3-substituted imidazo[1,2-a]pyridines, heterocyclic moiety commonly found medicinal...

In plant cells, an increase in cellular oxidants can have multiple effects, including the promotion of mixed disulfide bonds between glutathione and some proteins (S-glutathionylation). The present study focuses on cytosolic isoform glycolytic enzyme triosephosphate isomerase (cTPI) from Arabidopsis thaliana its reversible modification by glutathione. We used purified recombinant cTPI to demonstrate sensitivity inhibition N-ethylmaleimide, hydrogen peroxide diamide. Treatment with diamide...

Herein we report the discovery of benzo[a]imidazo[2,1,5-c,d]indolizine motif displaying tunable emission covering most visible spectrum. The polycyclic core is obtained from readily available amides via a chemoselective process involving Tf2O-mediated amide cyclodehydration, followed by intramolecular C–H arylation. Additionally, these fluorescent heterocycles are easily functionalized using electrophilic reagents, enabling divergent access to varied substitution. effects said substitution...

Partition on Celite columns, using both elution and extrusion techniques, was found to be a convenient satisfactory chromatographic method for preparative or analytical work involving carbohydrates their derivatives. The is superior other procedures in resolution of mixtures; cost, ease, speed operation; yield purity products; range applicability. To illustrate these advantages number specific examples are given partially methylated derivatives D-glucose D-xylose isolation products from...

A practical and highly stereoselective approach to access 2,6-disubstituted piperidines using an amidine auxiliary is reported. These were reduced the saturated piperidine rings with high diastereoselectivity.

Abstract The regioselective Ru II ‐catalyzed direct ortho ‐arylation of C‐3 aryl‐substituted imidazo[1,5‐ a ]azines with (hetero)aryl halides was investigated. employment and Pd catalysts in the same flask resulted two sequential distinct C–H bond arylations, which allowed rapid synthesis highly conjugated compounds.

1-Iodoalkynes are formed in moderate to high yields from readily accessible benzylic and allylic alkyl bromides by a one-pot homologation/double elimination procedure with iodoform (CHI(3)). The developed conditions include facile purification avoid the use of an excess triphenylphosphine (PPh(3)), as described classical Corey-Fuchs iodoalkynylation conditions. Replacing CHI(3) CHI(2)Cl allows isolation corresponding gem-(Z)-chloro-(E)-iodoalkene good yield stereoselectivity. Moreover,...

Using a catalytic amount of PdCl2(dppf)·CH2Cl2 in combination with Ag3PO4 and NaOAc, range arylated 1,2,3,4-tetrahydropyridines are synthesized good yields complete selectivity at the β-position. The reaction is compatible variety electron-donating electron-withdrawing aryl iodides as well heteroaryl iodides. application these tetrahydropyridines toward synthesis polysubstituted piperidines also demonstrated.

Key words quinolines - hydrogen transfer multicomponent synthesis Doebner reaction

Abstract The electrophilic activation of 2 H ‐azirines with triflic anhydride (Tf O) for an addition/cyclization reaction producing 2‐aryl‐pyrido[2,3‐ b ]pyrazines regioselectively is described. This proceeds via nucleophilic addition 3‐amino‐2‐fluoropyridines onto 1‐trifloyl‐aziridin‐2‐yl triflates and subsequent cyclization S N Ar. Desulfonylation oxidation provides a single regioisomer the aza‐bicyclic heterocycle after treatment Et 3 N. Optimization conditions lead to range in isolated...

Abstract Review: 548 refs.