Stereospecific Consecutive Epoxide Ring Expansion with Dimethylsulfoxonium Methylide

2010 ◽  
Vol 75 (18) ◽  
pp. 6229-6235 ◽  
Author(s):  
Ekaterina D. Butova ◽  
Anastasiya V. Barabash ◽  
Anna A. Petrova ◽  
Christian M. Kleiner ◽  
Peter R. Schreiner ◽  
...  
Keyword(s):  
Ring Expansion ◽  
Epoxide Ring ◽  
Dimethylsulfoxonium Methylide

ChemInform Abstract: Stereospecific Consecutive Epoxide Ring Expansion with Dimethylsulfoxonium Methylide.

ChemInform ◽  
2010 ◽  
Vol 42 (3) ◽  
pp. no-no
Author(s):  
Ekaterina D. Butova ◽  
Anastasiya V. Barabash ◽  
Anna A. Petrova ◽  
Christian M. Kleiner ◽  
Peter R. Schreiner ◽  
...  
Keyword(s):  
Ring Expansion ◽  
Epoxide Ring ◽  
Dimethylsulfoxonium Methylide

Synthesis of cyclic ethers via 5-exo iodonium assisted epoxide ring expansion.

1988 ◽  
Vol 29 (17) ◽  
pp. 2093-2096 ◽  
Author(s):  
Eleuterio Alvarez ◽  
Eduardo Manta ◽  
Julio D Martin ◽  
Matias L Rodriguez ◽  
Catalina Ruiz-Perez
Keyword(s):  
Ring Expansion ◽  
Epoxide Ring ◽  
Cyclic Ethers

scholarly journals Remarkable Influence of Cobalt Catalysis on Epoxide Ring-Opening with Sulfoxonium Ylides

Synthesis ◽  
2017 ◽  
Vol 49 (17) ◽  
pp. 3952-3956 ◽  
Author(s):  
Megan Jamieson ◽  
Nicola Brant ◽  
Margaret Brimble ◽  
Daniel Furkert
Keyword(s):  
Transition Metal ◽  
Ring Opening ◽  
Ring Expansion ◽  
Transition Metal Catalysts ◽  
Current Understanding ◽  
Epoxide Ring ◽  
Epoxide Ring Opening ◽  
Homoallylic Alcohols ◽  
Mechanistic Analysis ◽  
Oxetane Ring

Cobalt demonstrates a remarkable ability to catalytically divert the course of epoxide to oxetane ring expansion via reaction with a sulfoxonium ylide. An expanded survey of transition-metal catalysts has confirmed that cobalt salts uniquely instead deliver homoallylic alcohol products from epoxides, with retention of the original epoxide stereochemistry. The reaction is an unusual example of cobalt-catalysed epoxide­ ring-opening by a carbon nucleophile. A tandem Corey–Chaykovsky/epoxide olefination sequence giving homoallylic alcohols from aldehydes is further demonstrated along with preliminary mechanistic analysis. This communication summarises current understanding and ongoing studies into this intriguing new cobalt-mediated reactivity.

Synthesis of cyclic ethers via bromine assisted epoxide ring expansion

1986 ◽  
pp. 1277 ◽  
Author(s):  
Stephen G. Davies ◽  
Mario E. C. Polywka ◽  
Susan E. Thomas
Keyword(s):  
Ring Expansion ◽  
Epoxide Ring ◽  
Cyclic Ethers

ChemInform Abstract: Synthesis of Cyclic Ethers via 5-Exo Iodonium Assisted Epoxide Ring Expansion.

ChemInform ◽  
1988 ◽  
Vol 19 (40) ◽  
Author(s):  
E. ALVAREZ ◽  
E. MANTA ◽  
J. D. MARTIN ◽  
M. L. RODRIGUEZ ◽  
C. RUIZ-PEREZ
Keyword(s):  
Ring Expansion ◽  
Epoxide Ring ◽  
Cyclic Ethers

Synthesis, Structure and Reactivities of Pentacoordinated Phosphorus–Boron Bonded Compounds

2020 ◽  
Author(s):  
Nathan O'Brien ◽  
Naokazu Kano ◽  
Nizam Havare ◽  
Ryohei Uematsu ◽  
Romain Ramozzi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ring Expansion ◽  
Bicyclic Compound ◽  
Compound A ◽  
Ligand System ◽  
Large Bulk ◽  
Rearrangement Reaction ◽  
Hydride Abstraction ◽  
Pentacoordinated Phosphorus ◽  
Acids And Bases

<div>The isolation and reactivities of two pentacoordinated phosphorus–tetracoordinated boron bonded compounds were</div><div>explored. A strong Lewis acidic boron reagent and electron-withdrawing ligand system were required to form the</div><div>pentacoordinated phosphorus state of the P–B bond. The first compound, a phosphoranyl-trihydroborate, gave a THF</div><div>stabilised phosphoranyl-borane intermediate upon a single hydride abstraction in THF. This compound could undergo a</div><div>unique rearrangement reaction, that involved a two-fold ring expansion, to give an unusual fused bicyclic compound or it</div><div>could act as a mono-hydroboration reagent. The hydroboration reactivity of the intermediate was found to be more reactive</div><div>towards alkynes over alkenes with good to moderate regioselectivity towards the terminal carbon. The second compound,</div><div>a phosphoranyl-triarylborate, was found to have a vastly different reactivity to the trihydroborate as it was highly stable</div><div>towards acids and bases. This is thought to be due to the large bulk around the P–B bond as shown in the crystal structure</div>

Concise Synthesis of GB22 by Endo-Selective Siloxycyclopropane Arylation

2019 ◽  
Author(s):  
Hannah E. Burdge ◽  
Takuya Oguma ◽  
Takahiro Kawajiri ◽  
Ryan Shenvi
Keyword(s):  
Intramolecular Cyclization ◽  
Cross Coupling ◽  
Building Blocks ◽  
Ring Expansion ◽  
Dual Catalysis ◽  
Acid Labile

<div><div><div><p>The first synthesis of GB22 was accomplished by a con- cise, modular route. Two building blocks converged in a novel sp3-sp2 attached-ring coupling that used Ir/Ni dual-catalysis to reverse the regioselectivity of siloxycy- clopropane arylation. This cross-coupling proved general to access β-substituted tetralones via ring-expansion of indanone-derived siloxycyclopropanes. The congested, bridging rings of the GB alkaloids were completed using an aluminum-HFIP complex that effected intramolecular cyclization of an acid-labile substrate.</p></div></div></div>

Concise Synthesis of GB22 by Endo-Selective Siloxycyclopropane Arylation

2019 ◽  
Author(s):  
Hannah E. Burdge ◽  
Takuya Oguma ◽  
Takahiro Kawajiri ◽  
Ryan Shenvi
Keyword(s):  
Intramolecular Cyclization ◽  
Cross Coupling ◽  
Building Blocks ◽  
Ring Expansion ◽  
Dual Catalysis ◽  
Acid Labile

<div><div><div><p>The first synthesis of GB22 was accomplished by a con- cise, modular route. Two building blocks converged in a novel sp3-sp2 attached-ring coupling that used Ir/Ni dual-catalysis to reverse the regioselectivity of siloxycy- clopropane arylation. This cross-coupling proved general to access β-substituted tetralones via ring-expansion of indanone-derived siloxycyclopropanes. The congested, bridging rings of the GB alkaloids were completed using an aluminum-HFIP complex that effected intramolecular cyclization of an acid-labile substrate.</p></div></div></div>

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