Stereoselective Synthesis Of Cis Research Articles

Ketoreductase-catalyzed dynamic reductive kinetic resolution of sterically hindered 2-aryl-1,5-benzothiazepin-3,4(2H,5H)-diones: asymmetric synthesis of a key diltiazem precursor and its analogues

An efficient, green, and stereoselective synthesis of cis-(2S,3S)-2,3-dihydro-3-hydroxy-2-aryl-1,5-benzothiazepin-4(5H)-ones was developed via ketoreductase-catalyzed dynamic reductive kinetic resolution.

Stereodivergent and Stereoselective Synthesis of cis- and trans-4-Substituted Prolinols

Stereodivergent and Stereoselective Synthesis of cis- and trans-4-Substituted Prolinols

Stereoselective Synthesis of cis- and trans-3,4,5-Trisubstituted-1,3-oxazolidin-2-one Derivatives from 1,2-Amino Alcohol Monoesters and Aziridine-2-carboxylates

New cis-N-alkyl-1,3-oxazolidin-2-ones were prepared in moderate to good yields via phosgenation of erythro-1,2-aminoalcohol monoesters, accompanied by formation of aziridine by-products. On the other hand, their regioisomers trans-N-alkyl-1,3-oxazolidin-2-ones were prepared regio- and stereoselectively in good yields by ring expansion of trans-N-alkyl aziridine-2-carboxylates.

ChemInform Abstract: Stereoselective Synthesis of cis‐ or trans‐2,4‐Disubstituted Butyrolactones from Wynberg Lactone.

Abstract(R)‐Wynberg lactone (I) is used to prepare various asymmetric disubstituted butyrolactones in three or four steps.

Stereoselective synthesis of cis- or trans-2,4-disubstituted butyrolactones from Wynberg lactone

(R)-Wynberg lactone was used to prepare various asymmetric 2,4-disubstituted butyrolactones in three to four steps. Attainment of any possible stereoisomer, based upon commencement from (R)- or (S)-4-trichloromethyl-2-oxetanone, and the capacity to install disparate substituents at C2 make this approach particularly versatile.

Stereoselective synthesis of cis- and trans-2′,5′-disubstituted N-arylpyrrolo[3′,4′:1,9](C60-I h )[5,6]fullerenes by the 1,3-dipolar cycloaddition of azomethine ylides from dialkyl aziridinedicarboxylates to fullerene C60

A stereoselective method for the synthesis of 2′,5′-disubstituted N-arylpyrrolofullerenes from anilines, alkyl glyoxylates, alkyl diazoacetates, and fullerene C60 was proposed. The key step of the synthesis is the 1,3-dipolar cycloaddition reaction of fullerene with azomethine ylides generated by heating of dialkyl aziridinedicarboxylates. The thermal opening of the aziridine ring to azomethine ylide and the cycloaddition of the latter to C60 at 100 °C are nearly completely stereoselective: only trans-adducts are formed from cis-aziridines, whereas trans-aziridines give exclusively cis-adducts.

The stereoselective synthesis of cis-/trans-fused hexahydropyrano[4,3-b]chromenes via Prins cyclization trapping by a tethered nucleophile

A novel intramolecular Prins cyclization of (Z)-2-(5-hydroxypent-2-enyl)phenol with various aldehydes has been achieved using 10 mol% In(OTf)(3) and 30 mol% TsOH to produce the cis-fused hexahydropyrano[4,3-b]chromene derivatives in good yields, while the coupling of (E)-2-(5-hydroxypent-2-enyl)phenol with aldehydes under similar conditions affords the corresponding trans-fused hexahydropyrano[4,3-b]chromene derivatives.

Stereoselective synthesis of cis- and trans-4-acyl-β-lactams from vicinal diketones and ketoaldehydes

4-Acyl-β-lactams are important synthetic intermediates in both pharmaceutical and organic chemistry. Cis- and trans-4-acyl-β-lactams were synthesized stereoselectively from vicinal diketones via the formation of bulky and less bulky diimines as key intermediates, respectively. The diimines reacted with acyl chloride in the presence of triethylamine to give rise to the corresponding 4-imino-β-lactams, which were further hydrolyzed to afford 4-acyl-β-lactams. The cis- and trans selectivity is depended on the steric hindrance of the imine N-substituents. A series of cis-4-acyl-β-lactams were synthesized from vicinal ketoaldehydes via the formation of their monoimines and diimines as intermediates. Pyruvic aldehyde produced cis-4-acetyl-β-lactams and cis-4-formyl-β-lactams, respectively, through the reactions of its monoimine and diimine with acyl chlorides. Phenylglyoxal generated cis-4-benzoyl-β-lactams via its monoaldimine.

ChemInform Abstract: Oxidative Addition and Isomerization Reactions: The Stereoselective Synthesis of cis- and trans-Ph2TeX4.

Abstract A study of the stereoselective synthesis of cis- and trans-Ph2TeX4 (X=F,Cl) supports a two pathway mechanism in which oxidative addition leads to the cis isomer while subsequent isomerization leads to the trans isomer.

ChemInform Abstract: Stereoselective Synthesis of cis- and trans-β,γ-Unsaturated Carboxylic Esters via Reaction of 1-Alkenyldichloroboranes with Ethyl Diazoacetate.

ChemInform Abstract: Stereoselective Synthesis of cis- and trans-β,γ-Unsaturated Carboxylic Esters via Reaction of 1-Alkenyldichloroboranes with Ethyl Diazoacetate.

ChemInform Abstract: Stereoselective Synthesis of cis‐ and trans‐2,3‐Disubstituted Tetrahydrofurans via Oxonium—Prins Cyclization: Access to the Cordigol Ring System.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Stereoselective synthesis of cis- and trans-3-fluoro-1-phenylcyclobutyl amine

A stereoselective approach to the synthesis of cis- and trans-3-fluoro-1-phenylcyclobutylamine has been developed. Excellent stereoselectivity was obtained by the reduction of the appropriately substituted cyclobutanone to give either cis- or trans-isomers of 3-hydroxyl-1-phenylcyclobutylamine, which was stereoselectively converted to the 3-fluoro derivative.

Stereoselective Synthesis of N-Alkylaziridines from N-Chloroamines

We report the first racemic and stereoselective synthesis of cis- and trans-N-alkylaziridines viaN-chloroamines; using this methodology an N-3,4,5-trimethoxybenzylaziridine was synthesised and efficiently cleaved, affording the corresponding NH aziridine in high yield.

Stereoselective synthesis of N-alkylaziridines from N-chloroamines

We report the first racemic and stereoselective synthesis of cis- and trans-N-alkylaziridines viaN-chloroamines; using this methodology an N-3,4,5-trimethoxybenzylaziridine was synthesised and efficiently cleaved, affording the corresponding NH aziridine in high yield.

Stereoselective synthesis of cis- and trans-2,3-disubstituted eight-membered medium-ring ethers based on Ireland–Claisen rearrangement of 3-alkoxy-2-propenyl glycolate esters and ring-closing olefin metathesis

A simple stereoselective synthesis of cis- and trans-2,3-disubstituted medium-sized cyclic ethers has been developed based on geometry-selective synthesis of 3-alkoxy-2-propenyl glycolate esters, Ireland–Claisen rearrangement of the glycolate esters, and ring-closing olefin metathesis.

Transmetallation reactions of [Sn(R) 2(Ph 2PC 6H 4-2-S) 2] with metal complexes of the Group 10 : Stereoselective synthesis of cis-[M(Ph 2PC 6H 4-2-S) 2] (M=Ni, Pd, Pt)

The complexes cis-[M(Ph 2PC 6H 4-2-S) 2] M=Ni, Pd, Pt were stereoselectively synthesized by transmetallation reactions of [M(Cl) 2(NCC 6H 5) 2] M=Pd, Pt or NiCl 2·6H 2O with [Sn(R) 2(Ph 2PC 6H 4-2-S) 2] R=Ph, n Bu or t Bu. The conformation of the Pd and Pt derivatives being unequivocally confirmed by single crystal X-ray diffraction studies showing both metal centers to be into a slightly distorted square planar environment, the main distortion being due to the steric hindrance caused by the aromatic rings in the phosphine moiety.

ChemInform Abstract: A Novel Efficient and Stereoselective Synthesis of cis‐ or trans‐2,5‐Disubstituted Tetrahydrofurans.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A novel efficient and stereoselective synthesis of cis- or trans-2,5-disubstituted tetrahydrofurans

A general route to either cis- or trans-2,5-alkyl or aryl disubstituted tetrahydrofurans is described, using the nucleophilic addition of organolithium derivatives to tricyclic lactones, followed by a highly stereocontrolled acid-assisted reduction with sodium cyanoborohydride of the hemiketals formed. The stereoselectivity observed can be rationalized by the preferential approach of the hydride on the less hindered face of an oxonium ion intermediate.

ChemInform Abstract: First Stereoselective Synthesis of cis 3‐CF3‐Aziridine‐2‐carboxylates. A Route to New (Trifluoromethyl) α‐Functionalized β‐Amino Acids.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: A Stereoselective Synthesis of cis‐ and trans‐Fused Lactones via the Palladium(II)‐Catalyzed Carbonylation of Organomercurials.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.