Rare Medium-Sized Rings Prepared via Hydrolytic Imidazoline Ring Expansion (HIRE)

2018 ◽  
Vol 83 (17) ◽  
pp. 9707-9717 ◽  
Author(s):  
Angelina Osipyan ◽  
Alexander Sapegin ◽  
Alexander S. Novikov ◽  
Mikhail Krasavin
Keyword(s):  
Ring Expansion ◽  
Imidazoline Ring

An attempt at the hydrated imidazoline ring expansion (HIRE) of diarene-fused [1,4]diazepinones delivers selective dopamine D2 receptor ligands

Synthesis ◽  
2021 ◽  
Author(s):  
Sergey Grintsevich ◽  
Alexander V. Sapegin ◽  
Andrzej Bojarski ◽  
Beata Duszyńska ◽  
Mikhail Krasavin
Keyword(s):  
Dopamine D2 Receptor ◽  
D2 Receptor ◽  
Ring Expansion ◽  
Side Chain ◽  
Receptor Ligands ◽  
Structure Activity Relationships ◽  
Dopamine D2 ◽  
Structure Activity ◽  
Imidazoline Ring ◽  
Selective Dopamine

Attempts to extend the hydrated imidazoline ring expansion (HIRE) strategy to a series of diarene-fused [1,4]diazepinones (earlier applied successfully to bis-pyrido substrate nevirapine) resulted in no ring expansion but rather 2-aminoethyl side chain expulsion. This seeming setback (setting the limitations to the HIRE methodology substrate scope) led to the discovery of selective dopamine D2 ligands with elements of structure-activity relationships.

Zooming in on the hydrated imidazoline ring expansion: Factors influencing the rate of N → N′ aroyl migration in N-aroyl-N-(hetero)aryl ethylenediamines

2020 ◽  
Vol 61 (42) ◽  
pp. 152423
Author(s):  
Kseniya Lavit ◽  
Elena Reutskaya ◽  
Sergey Grintsevich ◽  
Alexander Sapegin ◽  
Mikhail Krasavin
Keyword(s):  
Ring Expansion ◽  
Factors Influencing ◽  
Imidazoline Ring

scholarly journals Structurally diverse arene-fused ten-membered lactams accessed via hydrolytic imidazoline ring expansion

2017 ◽  
Vol 15 (14) ◽  
pp. 2906-2909 ◽  
Author(s):  
Alexander Sapegin ◽  
Angelina Osipyan ◽  
Mikhail Krasavin
Keyword(s):  
Medicinal Chemistry ◽  
Ring Expansion ◽  
Membered Ring ◽  
Synthetic Methods ◽  
Ring Systems ◽  
New Hire ◽  
Imidazoline Ring

A facile approach to hitherto unknown ten-membered ring systems via a hydrolytic imidazoline ring expansion (HIRE) is described. Medium-sized rings are scarce in the contemporary medicinal chemistry toolbox. The new HIRE strategy broadens the arsenal of synthetic methods to obtain such scaffolds.

An Alternative Approach to the Hydrated Imidazoline Ring Expansion (HIRE) of Diarene-Fused [1.4]Oxazepines

2020 ◽  
Author(s):  
Sergey Grintsevich ◽  
Alexander Sapegin ◽  
Elena Reutskaya ◽  
Stefan Peintner ◽  
Máté Erdélyi ◽  
...  
Keyword(s):  
Ring Expansion ◽  
Alternative Approach ◽  
Imidazoline Ring

Rethinking Hydrolytic Imidazoline Ring Expansion: A Common Approach to the Preparation of Medium-Sized Rings via Side-Chain Insertion into [1.4]Oxa- and [1.4]Thiazepinone Scaffolds

2018 ◽  
Vol 84 (4) ◽  
pp. 1693-1705 ◽  
Author(s):  
Elena Reutskaya ◽  
Angelina Osipyan ◽  
Alexander Sapegin ◽  
Alexander S. Novikov ◽  
Mikhail Krasavin
Keyword(s):  
Ring Expansion ◽  
Side Chain ◽  
Imidazoline Ring

scholarly journals Front Cover: An Alternative Approach to the Hydrated Imidazoline Ring Expansion (HIRE) of Diarene‐Fused [1.4]Oxazepines (Eur. J. Org. Chem. 35/2020)

2020 ◽  
Vol 2020 (35) ◽  
pp. 5635-5635
Author(s):  
Sergey Grintsevich ◽  
Alexander Sapegin ◽  
Elena Reutskaya ◽  
Stefan Peintner ◽  
Máté Erdélyi ◽  
...  
Keyword(s):  
Ring Expansion ◽  
Front Cover ◽  
Alternative Approach ◽  
Imidazoline Ring

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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