A tandem Prins spirocyclization for the stereoselective synthesis of tetrahydrospiro[chroman-2,4′-pyran] derivatives

2016 ◽  
Vol 14 (12) ◽  
pp. 3234-3237 ◽  
Author(s):  
B. V. Subba Reddy ◽  
V. Hanuman Reddy ◽  
Durgaprasad Medaboina ◽  
B. Sridhar ◽  
Y. V. Rami Reddy
Keyword(s):  
Stereoselective Synthesis ◽  
Cascade Process ◽  
Reaction Conditions

A novel cascade process has been developed for the synthesis of tetrahydrospiro[chroman-2,4′-pyran] derivatives by condensation of aldehydes with 2-(5-hydroxy-3-methylenepentyl)phenols using BF3·OEt2 under mild reaction conditions.

Stereoselective Synthesis of Bicyclic Pyrrolidines by a Rhodium-Catalyzed Cascade Process

2004 ◽  
Vol 43 (48) ◽  
pp. 6713-6716 ◽  
Author(s):  
Ming Yan ◽  
Neil Jacobsen ◽  
Wenhao Hu ◽  
Luisa S. Gronenberg ◽  
Michael P. Doyle ◽  
...  
Keyword(s):  
Stereoselective Synthesis ◽  
Cascade Process

N-TFA-Gly-Bt-Based Stereoselective Synthesis of Substituted 3-Amino Tetrahydro-2H-pyran-2-ones via an Organocatalyzed Cascade Process

2019 ◽  
Vol 84 (16) ◽  
pp. 10526-10534 ◽  
Author(s):  
Liuqing Han ◽  
Ke Li ◽  
Haitong Xu ◽  
Tao Mei ◽  
Yali Sun ◽  
...  
Keyword(s):  
Stereoselective Synthesis ◽  
Cascade Process

scholarly journals Distinctive reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines under photoredox conditions

2020 ◽  
Vol 16 ◽  
pp. 1335-1342
Author(s):  
Shrikant D Tambe ◽  
Kwan Hong Min ◽  
Naeem Iqbal ◽  
Eun Jin Cho
Keyword(s):  
Electron Transfer ◽  
Stereoselective Synthesis ◽  
Aliphatic Amine ◽  
Cross Coupling ◽  
The Other ◽  
Single Electron Transfer ◽  
Reductive Coupling ◽  
Phenyl Substituent ◽  
Reaction Conditions ◽  
Judicious Choice

A simple photocatalytic method was developed for the synthesis of unsymmetrical 1,2-diamines by the unprecedented reductive coupling of N-benzylidene-[1,1'-biphenyl]-2-amines with an aliphatic amine. The presence of a phenyl substituent in the aniline moiety of the substrate was critical for the reactivity. The reaction proceeded via radical–radical cross-coupling of α-amino radicals generated by proton-coupled single-electron transfer in the presence of an Ir photocatalyst. On the other hand, symmetrical 1,2-diamines were selectively produced from the same starting materials by the judicious choice of the reaction conditions, showcasing the distinct reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines. The developed method can be employed for the synthesis of various bulky vicinal diamines, which are potential ligands in stereoselective synthesis.

ChemInform Abstract: A Novel Prins Cascade Process for the Stereoselective Synthesis of Oxa-bicycles.

ChemInform ◽  
2015 ◽  
Vol 46 (27) ◽  
pp. no-no
Author(s):  
B. V. Subba Reddy ◽  
A. Venkateswarlu ◽  
B. Sridevi ◽  
Kanakaraju Marumudi ◽  
A. C. Kunwar ◽  
...  
Keyword(s):  
Stereoselective Synthesis ◽  
Cascade Process

Regio- and Stereoselective Synthesis of Spirooxindoles via Mizoroki–Heck Coupling of Aryl Iodides

Synlett ◽  
2018 ◽  
Vol 30 (01) ◽  
pp. 82-88 ◽  
Author(s):  
Mats Larhed ◽  
Ahmed Adeyemi ◽  
Alexander Wetzel ◽  
Joakim Bergman ◽  
Jonas Brånalt
Keyword(s):  
Stereoselective Synthesis ◽  
Double Bond Position ◽  
Unnatural Amino Acid ◽  
Spiro Compounds ◽  
Amino Acid Derivatives ◽  
Heck Coupling ◽  
Reaction Conditions ◽  
Aryl Iodide ◽  
Aryl Iodides ◽  
High Stereoselectivity

A method for highly regio- and stereoselective intramolecular Mizoroki–Heck 5-exo cyclization of aryl iodides to the corresponding spirooxindoles has been developed. Electron-rich and electron-deficient aryl iodide precursors were selectively ring-closed with high stereoselectivity and good yields. The double-bond position in the cyclopentene ring was controlled by careful choice of reaction conditions. These rare spiro compounds were further functionalized to rigidified unnatural amino acid derivatives by a subsequent gas-free Pd(0)-catalyzed alkoxycarbonylation, followed by selective O- and N-deprotections.

Stereoselective Synthesis of Vinyl Iodides through Copper(I)-Catalyzed Finkelstein-Type Halide-Exchange Reaction

Synthesis ◽  
2017 ◽  
Vol 49 (12) ◽  
pp. 2727-2732 ◽  
Author(s):  
Xiujuan Feng ◽  
Haixia Zhang ◽  
Wenbo Lu ◽  
Yoshinori Yamamoto ◽  
Abdulrahman Almansour ◽  
...  
Keyword(s):  
Exchange Reaction ◽  
Potassium Iodide ◽  
Efficient Method ◽  
Stereoselective Synthesis ◽  
Copper Catalyst ◽  
Reaction Conditions ◽  
Halide Exchange ◽  
Vinyl Iodides

An efficient method for the stereoselective synthesis of vinyl iodides is described. The reactions of vinyl bromides with potassium iodide proceed smoothly in the presence of a copper catalyst under mild reaction conditions to produce the corresponding vinyl iodides stereospecifically and in satisfactory to excellent yields.

scholarly journals Functional Poly(dihalopentadiene)s: Stereoselective Synthesis, Aggregation-Enhanced Emission and Sensitive Detection of Explosives

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 821 ◽  
Author(s):  
Ting Han ◽  
Yun Zhang ◽  
Benzhao He ◽  
Jacky Lam ◽  
Ben Tang
Keyword(s):  
Stereoselective Synthesis ◽  
Aqueous Media ◽  
Wavelength Region ◽  
Polymeric Materials ◽  
High Refractive Index ◽  
Fluorescent Chemosensors ◽  
Reaction Conditions ◽  
Film Forming ◽  
Detection Of Explosives ◽  
Novel Structures

The development of polymeric materials with novel structures and unique properties and functionalities is of both academic and industrial significance. In this work, functional poly(dihalopentadiene)s were synthesized by boron trihalide-mediated multicomponent polymerization routes in a stereoselective manner. The polymerizations of tetraphenylethylene-containing diyne, BX3 (X = Cl, Br) and p-tolualdehyde proceed smoothly in dichloromethane under mild conditions to afford high molecular weight poly(dihalopentadiene)s with a predominant (Z,Z)-configuration in moderate to good yields. The reaction conditions and the boron trihalide used were found to have great effects on the stereochemistry of the resulting polymer structures. The obtained poly(1,5-dihalo-(Z,Z)-1,4-pentadiene)s possess high thermal stability and good film-forming ability. Their thin films show high refractive index of 1.9007–1.6462 in a wide wavelength region of 380–890 nm with low optical dispersion. The polymers are weakly emissive in dilute solutions but become highly emissive upon aggregated, demonstrating a unique phenomenon of aggregation-enhanced emission. Their nanoaggregates in aqueous media can serve as sensitive fluorescent chemosensors for the detection of explosives with a superamplification effect and a low detection limit.

A novel Prins cascade process for the stereoselective synthesis of oxa-bicycles

2015 ◽  
Vol 13 (9) ◽  
pp. 2669-2672 ◽  
Author(s):  
B. V. Subba Reddy ◽  
A. Venkateswarlu ◽  
B. Sridevi ◽  
Kanakaraju Marumudi ◽  
A. C. Kunwar ◽  
...  
Keyword(s):  
Stereoselective Synthesis ◽  
Cascade Process ◽  
Mild Conditions ◽  
Excellent Selectivity

E- and Z-9-Methyldeca-3,8-dien-1-ols undergo smooth cyclization with aldehydes in the presence of 20 mol% AgSbF6 under extremely mild conditions to generate the corresponding oxa-bicycles in good yields with excellent selectivity.

Cyclizations using Selenium Chemistry for Substituted 3-Hydroxypiperidines and 3-Hydroxypyrrolidines

2011 ◽  
Vol 64 (10) ◽  
pp. 1327 ◽  
Author(s):  
Matthew A. Cooper ◽  
A. David Ward
Keyword(s):  
Stereoselective Synthesis ◽  
Nitrogen Heterocycles ◽  
Kinetic Control ◽  
Current Interest ◽  
Reaction Conditions ◽  
Hydroxide Ion ◽  
New Methods ◽  
Electrophilic Activation ◽  
Related Compounds

The development of new methods for the stereoselective synthesis of nitrogen heterocycles is of current interest because of increasing demands for the syntheses of biologically important alkaloids and related compounds. It is shown that selenium-induced cyclization of 4-hydroxy-5-pentenylamines occurs regio- and stereo-selectively to afford cis-3-hydroxy-2-phenylselenomethylpyrrolidines, whereas 5-hydroxy-6-hexenylamines cyclize and give trans-3-hydroxy-2-phenylselenomethylpiperidines, with some compounds forming stable hydrates. In all cases cyclization proceeds regioselectively to give only the exo adducts with moderate to good diastereoselectivity. The reaction appeared to be under kinetic control as product ratios did not alter with time and the separated diastereomers did not interconvert when resubjected to the reaction conditions. These phenylseleno-substituted compounds could be transformed to diols by substitution of the corresponding selenone with a hydroxide ion. Substituted pyrrolidines and piperidines were thus afforded from unsaturated protected amines by electrophilic activation with SeII, followed by oxidation of the intermediate to SeVI and substitution with nucleophiles.

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