Synthetic Approaches to Non-Tropane, Bridged, Azapolycyclic Ring Systems Containing Seven-Membered Carbocycles

Synthesis ◽  
2020 ◽  
Vol 53 (01) ◽  
pp. 65-78
Author(s):  
Daniel R. Griffith ◽  
Aaron H. Shoemaker
Keyword(s):  
Building Blocks ◽  
Short Review ◽  
Ring Expansion ◽  
Membered Ring ◽  
Biologically Active ◽  
Ring Systems ◽  
Ring Expansions ◽  
Carbocyclic Rings ◽  
Synthetic Approaches ◽  
Acyclic Precursor

AbstractThis Short Review highlights various synthetic approaches to bridged azabicyclic ring systems containing seven-membered carbocyclic rings. Such ring systems are common to a number of biologically active natural products. The seven-membered ring in such systems is generally formed in one of four ways: 1) cyclization of an acyclic precursor; 2) ring expansion or rearrangement of a different ring size; 3) cycloaddition; and 4) use of a synthetic building block with the seven-membered ring already present. Representative examples of each approach from both total synthesis and methodological studies are discussed, with an emphasis on work publishedin the last twenty years.1 Introduction2 Cyclization Reactions3 Ring Expansions and Rearrangements4 Cycloadditions5 Strategies Involving Seven-Membered Ring Building Blocks6 Conclusion

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.

scholarly journals Modern Approaches to the Synthesis and Transformations of Practically Valuable Benzothiazole Derivatives

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2190
Author(s):  
Larisa V. Zhilitskaya ◽  
Bagrat A. Shainyan ◽  
Nina O. Yarosh
Keyword(s):  
Green Chemistry ◽  
Building Blocks ◽  
Biologically Active ◽  
New Drugs ◽  
Synthesis Methods ◽  
Atom Economy ◽  
One Pot ◽  
Benzothiazole Derivatives ◽  
Pharmacologically Active ◽  
Synthetic Approaches

The review is devoted to modern trends in the chemistry of 2-amino and 2-mercapto substituted benzothiazoles covering the literature since 2015. The reviewed heterocycles belong to biologically active and industrially demanded compounds. Newly developed synthesis methods can be divided into conventional multistep processes and one-pot, atom economy procedures, realized using green chemistry principles and simple reagents. The easy functionalization of the 2-NH2 and 2-SH groups and the benzene ring of the benzothiazole moiety allows considering them as highly reactive building blocks for organic and organoelement synthesis, including the synthesis of pharmacologically active heterocycles. The review provides a summary of findings, which may be useful for developing new drugs and materials and new synthetic approaches and patterns of reactivity.

The formation of cycloheptenone and cycloheptadienones from bicyclo[3.2.0]heptanone derivatives. An acid-catalyzed, two carbon ring expansion reaction

1976 ◽  
Vol 54 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Kenneth E. Hine ◽  
Ronald F. Childs
Keyword(s):  
Ring Expansion ◽  
Membered Ring ◽  
Acid Solutions ◽  
Ring Expansions ◽  
Carbon Ring ◽  
Ether Mixture ◽  
Synthetic Utility ◽  
Acid Catalyzed ◽  
Ring Expansion Reaction ◽  
Strong Acids

In strong acids, such as FSO3H and 96% H2SO4, bicyclo[3.2.0]heptan-6-one and bicyclo[3.2.0]hept-2-en-7-one undergo a clean isomerization to form protonated cyclohept-2-enone and cyclohepta-2,4-dienone, respectively. Substituted derivatives undergo comparable ring expansions when dissolved in these strong acids. The seven-membered ring ketones can be recovered on quenching the acid solutions with a NaHCO3–ether mixture. In contrast, bicyclo[3.2.0]hept-2-en-6-one when dissolved in FSO3H rearranged to give protonated 1-acetylcyclopentadiene. The mechanism and synthetic utility of these reactions is discussed.

Synthetic approaches toward diversely substituted 1,2,2-triarylethanones

2021 ◽  
Vol 25 ◽  
Author(s):  
Rodrigo Abonia ◽  
Oscar Montoya
Keyword(s):  
Carbonyl Compounds ◽  
Bond Activation ◽  
Building Blocks ◽  
Biologically Active ◽  
Carbon Carbon Bond ◽  
Key Points ◽  
Carbon Carbon Bonds ◽  
Reported Data ◽  
Synthetic Approaches ◽  
Free Metal

: Carbon–carbon bond formation is the essence of organic synthesis, and for that, many strategies have been developed to accomplish this goal. Several of these strategies are conducted to form diverse structures bearing the α,α-diarylcarbonyl motif, in form of 1,2,2-triarylethanones, which are unities present in a number of natural products and biologically active compounds.These privileged carbonyl compounds have been used as building blocks or intermediates for the synthesis of dibenzo[a,c]phenanthridines, analogues of biologically active benzo[c]phenanthridine alkaloids, as well as, a useful synthon for Droloxifene and remarkably for Tamoxifen, the most widely used drug for the treatment of breast cancer. Focusing on the literature progress since 2000 to 2020 and considering the synthetic and biologically value of the aforementioned carbonyl compounds, the present review explores the diverse metal-free, metal-mediated, C–H bond activation, α-monoarylation, α,α-diarylation, umpolung processes, N-heterocyclic carbene (NHC), deoxygenation, among others,synthetic approaches directed to the synthesis of 1,2,2-triarylethanone derivatives. Moreover, several of their mechanistic proposals are also briefly discussed in this review. In view that most of these strategies are accompanied of carbon–carbon bonds formation through ketone-based α-arylation processes,the reported data are organized into concise Tables/Schemes to facilitate comparison, and to underscore the key points of this review.

Recent Progress in the Synthesis of Pyrimidine Heterocycles: A Review

2020 ◽  
Vol 24 (10) ◽  
pp. 1055-1096
Author(s):  
Pradip Kumar Maji
Keyword(s):  
Broad Spectrum ◽  
Recent Progress ◽  
Biological Activities ◽  
Building Blocks ◽  
Heterocyclic Ring ◽  
Antibacterial Activities ◽  
Review Article ◽  
Biologically Active ◽  
Synthetic Strategy ◽  
Synthetic Approaches

Pyrimidine heterocycles are proven to be biologically active heterocycles, found in many biological systems, displaying a broad spectrum of biological activities including anticancer, anxiolytic, antioxidant, antiviral, antifungal, anticonvulsant, antidepressant and antibacterial activities. Recently, various synthetic approaches, synthetic strategy, the variation of substrates and study devoted towards the evaluation of biological activities for the pyrimidine heterocycles have been reported in the literature. This review article describes the synthesis of various biologically interesting pyrimidine heterocyclic ring systems using various nitrogen building blocks.

scholarly journals The chemistry of thujone. XV. A versatile route to antifeedants of the polygodial family

1990 ◽  
Vol 68 (10) ◽  
pp. 1698-1708 ◽  
Author(s):  
James P. Kutney ◽  
Krystyna Piotrowska ◽  
Yong-Huang Chen ◽  
Kwok-Ping Norman Cheng ◽  
Zhenyong Gao ◽  
...  
Keyword(s):  
Cyclopropane Ring ◽  
Ring Expansion ◽  
Ring System ◽  
Membered Ring ◽  
Ring Systems ◽  
Tertiary Carbon ◽  
Key Features

Utilizing thujone-derived intermediates, efficient routes to the natural polygodial family of antifeedants as well as novel analogues within this family are described. One of the key features of this study involves the insertion of an oxygen function into a tertiary carbon center adjacent to a cyclopropane ring system thus providing convenient intermediates for subsequent elaboration. An interesting ring expansion of five-membered to six-membered ring systems by means of tri-n-butyltin hydride is also described. Keywords: antifeedants, polygodial, thujone.

Catalytic Synthesis of Cyclic Guanidines via Hydrogen Atom Transfer and Radical-Polar Crossover

2020 ◽  
Author(s):  
Shunya Ohuchi ◽  
Hiroki Koyama ◽  
Hiroki Shigehisa
Keyword(s):  
Hydrogen Atom ◽  
Functional Group ◽  
Hydrogen Atom Transfer ◽  
Catalytic Synthesis ◽  
Membered Ring ◽  
Biologically Active ◽  
Atom Transfer ◽  
Powerful Method ◽  
Protective Groups ◽  
The Common

A catalytic synthesis of cyclic guanidines, which are found in many biologically active compounds and natu-ral products, was developed, wherein transition-metal hydrogen atom transfer and radical-polar crossover were employed. This mild and functional-group tolerant process enabled the cyclization of alkenyl guanidines bearing common protective groups, such as Cbz and Boc. This powerful method not only provided the common 5- and 6-membered rings but also an unusual 7-membered ring. The derivatization of the products afforded various heterocycles. We also investigated the se-lective cyclization of mono-protected or hetero-protected (TFA and Boc) alkenyl guanidines and their further derivatiza-tions.

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>

Synthesis and Biological Potentials of Quinoline Analogues: A Review of Literature

2019 ◽  
Vol 16 (7) ◽  
pp. 653-688 ◽  
Author(s):  
Leena Kumari ◽  
Salahuddin ◽  
Avijit Mazumder ◽  
Daman Pandey ◽  
Mohammad Shahar Yar ◽  
...  
Keyword(s):  
Biological Activity ◽  
Heterocyclic Compounds ◽  
Building Blocks ◽  
Vital Role ◽  
Review Of Literature ◽  
Drug Discovery Process ◽  
Active Compounds ◽  
Lead Compounds ◽  
Synthetic Approaches ◽  
Derivatives Of

Heterocyclic compounds are well known for their different biological activity. The heterocyclic analogs are the building blocks for synthesis of the pharmaceutical active compounds in the organic chemistry. These derivatives show various type of biological activity like anticancer, antiinflammatory, anti-microbial, anti-convulsant, anti-malarial, anti-hypertensive, etc. From the last decade research showed that the quinoline analogs plays a vital role in the development of newer medicinal active compounds for treating various type of disease. Quinoline reported for their antiviral, anticancer, anti-microbial and anti-inflammatory activity. This review will summarize the various synthetic approaches for synthesis of quinoline derivatives and to check their biological activity. Derivatives of quinoline moiety plays very important role in the development of various types of newer drugs and it can be used as lead compounds for future investigation in the field of drug discovery process.

Sign in / Sign up

Export Citation Format

Share Document