Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Acid-catalyzed ring-opening reactions of a cyclopropanated 3-aza-2-oxabicyclo[2.2.1]hept-5-ene with alcohols.

ABSTRACT: The acid-catalyzed ring-opening reactions of a cyclopropanated 3-aza-2-oxabicylic alkene using alcohol nucleophiles were investigated. Although this acid-catalyzed ring-opening reaction did not cleave the cyclopropane unit as planned, this represent the first examples of ring-openings of cyclopropanated 3-aza-2-oxabicyclo[2.2.1]alkenes that lead to the cleavage of the C-O bond instead of the N-O bond. Different acid catalysts were tested and it was found that pyridinium toluenesulfonate in methanol gave the best yields in the ring-opening reactions. The scope of the reaction was successfully expanded to include primary, secondary, and tertiary alcohol nucleophiles. Through X-ray crystallography, the stereochemistry of the product was determined which confirmed an SN2-like mechanism to form the ring-opened product.

SUBMITTER: Tait K

PROVIDER: S-EPMC5753073 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Acid-catalyzed ring-opening reactions of a cyclopropanated 3-aza-2-oxabicyclo[2.2.1]hept-5-ene with alcohols.

Tait Katrina K Horvath Alysia A Blanchard Nicolas N Tam William W

Beilstein journal of organic chemistry 20171227

The acid-catalyzed ring-opening reactions of a cyclopropanated 3-aza-2-oxabicylic alkene using alcohol nucleophiles were investigated. Although this acid-catalyzed ring-opening reaction did not cleave the cyclopropane unit as planned, this represent the first examples of ring-openings of cyclopropanated 3-aza-2-oxabicyclo[2.2.1]alkenes that lead to the cleavage of the C-O bond instead of the N-O bond. Different acid catalysts were tested and it was found that pyridinium toluenesulfonate in metha ...[more]

PMID: 29564016

Similar Datasets

Regio- and stereoselective indium triflate-mediated nucleophilic ring-opening reactions of 3-aza-2-oxabicyclo[2.2.1]hept-5-ene and -[2.2.2]oct-5-ene systems.

Project description:Indium triflate-mediated nucleophilic ring-opening reactions of 3-aza-2-oxabicyclo[2.2.1]hept-5-ene and -[2.2.2]oct-5-ene systems with alcohols and water were investigated. Reactions of [2.2.1] bicyclic systems gave anti-1,2-, anti-1,4- and syn-1,4-ring-opened products with moderate to excellent regio- and stereoselectivity. When [2.2.2] bicyclic systems were subjected to similar reaction conditions, only anti-1,2 and anti-1,4-ring-opened products were obtained.

| S-EPMC2759854 | biostudies-literature

Stereochemistry of ring-opening/cross metathesis reactions of exo- and endo-7-oxabicyclo[2.2.1]hept-5-ene-2-carbonitriles with allyl alcohol and allyl acetate.

Project description:The ROCM reactions of exo- and endo-2-cyano-7-oxanorbornenes with allyl alcohol or allyl acetate promoted by different ruthenium alkylidene catalysts were studied. The stereochemical outcome of the reactions was established. The issues concerning chemo- (ROCM vs ROMP), regio- (1-2- vs 1-3-product formation), and stereo- (E/Z isomerism) selectivity of reactions under various conditions are discussed. Surprisingly good yields of the ROCM products were obtained under neat conditions.

| S-EPMC4661012 | biostudies-literature

N-Carbamothioyl-amino-7-oxabicyclo-[2.2.1]hept-5-ene-2,3-dicarboximide.

Project description:The title compound, C(9)H(9)N(3)O(3)S, comprises a racemic mixture of chiral mol-ecules containing four stereogenic centres. The cyclo-hexane ring tends towards a boat conformation, while the tetra-hydro-furan ring and the dihydro-furan ring adopt envelope conformations. The dihedral angle between the thio-semicarbazide fragment and the fused-ring system is 77.20?(10)°. The crystal structure is stabilized by two inter-molecular N-H?O hydrogen bonds.

| S-EPMC3011812 | biostudies-other

Palladium-catalyzed ring-opening reactions of cyclopropanated 7-oxabenzonorbornadiene with alcohols.

Project description:Palladium-catalyzed ring-opening reactions of cyclopropanated 7-oxabenzonorbornadiene derivatives using alcohol nucleophiles were investigated. The optimal conditions were found to be 10 mol % PdCl2(CH3CN)2 in methanol, offering yields up to 92%. The reaction was successful using primary, secondary and tertiary alcohol nucleophiles and was compatible with a variety of substituents on cyclopropanated oxabenzonorbornadiene. With unsymmetrical C1-substituted cyclopropanated 7-oxabenzonorbornadienes, the regioselectivity of the reaction was excellent, forming only one regioisomer in all cases.

| S-EPMC5082584 | biostudies-literature

N-(4-Chloro-phen-yl)-7-oxabicyclo-[2.2.1]hept-5-ene-2,3-dicarboximide.

Project description:In the title racemic compound, C(14)H(10)ClNO(3), which contains four stereogenic centres, the cyclo-hexane ring tends towards a boat conformation, while the tetra-hydro-furan and dihydro-furan rings adopt envelope conformations. The dihedral angle between the mean planes of the pyrrolidine-2,5-dione unit and the 4-chloro-phenyl ring is 49.0?(2)°.

| S-EPMC3011550 | biostudies-other

Regioselective palladium-catalyzed ring-opening reactions of C1-substituted oxabicyclo[2,2,1]hepta-2,5-diene-2,3-dicarboxylates.

Project description:Palladium-catalyzed ring-opening reactions of C1 substituted 7-oxanorbornadiene derivatives with aryl iodides were investigated. The optimal conditions for this reaction were found to be PdCl2(PPh3)2, ZnCl2, Et3N and Zn in THF. Both steric and electronic factors played a role in the outcome of the reaction as increasing the steric bulk on the bridgehead carbon decreased the yield. These reactions were found to be highly regioselective, giving only one of the two possible regioisomers in all cases. A diverse collection of novel, highly substituted biphenyl derivatives were obtained.

| S-EPMC4778517 | biostudies-literature

Methyl 2-diphenyl-phosphor-yloxy-2-aza-bicyclo-[2.2.1]hept-5-ene-3-exo-carboxyl-ate.

Project description:In the title compound, C(20)H(20)NO(4)P, the dihedral angle between the phenyl rings is 68.52 (7)°. In the crystal structure, the mol-ecules are linked by a weak C-H⋯π(arene) inter-action along [010] involving the phenyl CH group and the phenyl rings. There are no further significant inter-molecular inter-actions.

| S-EPMC2968096 | biostudies-literature

Benzothia-zol-2-amine-3-meth-oxy-carbonyl-7-oxabicyclo-[2.2.1]hept-5-ene-2-carb-oxy-lic acid (1/1).

Project description:In the title 1:1 adduct, C(7)H(6)N(2)S·C(9)H(10)O(5), all non-H atoms of the benzothia-zol-2-amine mol-ecule are essentially coplanar, with a maximum deviation of 0.0286?(9)?Å for the S atom. In the crystal, inter-molecular N-H?O and O-H?N hydrogen bonds connect two mol-ecules of each type into centrosymmetric four-component clusters.

| S-EPMC3050333 | biostudies-literature

Rhodium(I)-catalyzed nucleophilic ring-opening reactions of oxabicyclo adducts derived from the [4 + 2]-cycloaddition of 2-imido-substituted furans.

Project description:A series of 2-imido-substituted furans containing tethered unsaturation were prepared by the addition of the lithium carbamate of furan-2-ylcarbamic acid tert-butyl ester to a solution of the mixed anhydride of an appropriately substituted 3-butenoic acid. The initially formed imido furans undergo a rapid intramolecular [4 + 2]-cycloaddition at room temperature to deliver the Diels-Alder cycloadducts in good to excellent yield. Isolation of the highly labile oxabicyclic adduct is believed to be a consequence of the lower reaction temperatures employed as well as the presence of the extra carbonyl group, which diminishes the basicity of the nitrogen atom, thereby retarding the ring cleavage/rearrangement reaction generally encountered with related systems. By using a Rh(I)-catalyzed ring opening of the oxabicyclic adduct with various nucleophilic reagents, it was possible to prepare highly functionalized hexahydro-1H-indol-2(3H)-one derivatives in good yield. The major stereoisomer obtained possesses a cis-relationship between the nucleophile and hydroxyl group in the ring-opened product. The stereochemistry was unequivocally established by X-ray crystallographic analysis. Coordination of Rh(I) to the alkenyl pi-bond followed by a nitrogen-assisted cleavage of the carbon-oxygen bond occurs to furnish a pi-allyl rhodium(III) species. Addition of the nucleophile then occurs from the least hindered terminus of the resulting pi-allyl rhodium(III) complex. Proton exchange followed by rhodium(I) decomplexation ultimately leads to the cis-diastereomer.

| S-EPMC2495029 | biostudies-literature

Convergent and stereodivergent synthesis of complex 1-aza-7-oxabicyclo[2.2.1]heptanes.

Project description:A convergent and stereodivergent pathway to highly substituted 1-aza-7-oxabicyclo[2.2.1]heptanes is described. It begins with a coupling reaction involving allylic alcohol, aldehyde, and LiHMDS to produce stereodefined primary homoallylic amines. Subsequent N-oxidation and condensation with formaldehyde or glyoxylate defines a convenient entry to densely functionalized homoallylic nitrones whose intramolecular annulation can be controlled to deliver one of two distinct heterocyclic skeletons, each with ≥20:1 stereoselection. Control of the stereochemistry in these reactions results from both control of the nitrone geometry and selective partitioning of the reaction pathway between direct [3 + 2] cycloaddition and tandem [3,3] rearrangement/[3 + 2] cycloaddition.

| S-EPMC3116711 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data