Synthesis and Applications of Cyclopropanones and their Equivalents as Three-Carbon Building Blocks in Organic Synthesis

Synthesis ◽  
2021 ◽  
Author(s):  
Yujin Jang ◽  
Roger Machin-Rivera ◽  
Vincent Lindsay
Keyword(s):  
Organic Synthesis ◽  
Ring Opening ◽  
Building Blocks ◽  
Ring Expansion ◽  
Ring System ◽  
Small Ring ◽  
Future Directions ◽  
Highly Strained ◽  
And Storage

Cyclopropanone derivatives constitute highly strained cycloalkanones with promising applications as three-carbon building blocks in organic synthesis. Due to the presence of a ketone in such a small ring system, all C–C bonds and the carbonyl group are considered to be labile in suitable conditions, leading to a wide variety of synthetic disconnections, including nucleophilic addition, ring expansion, ring-opening and (formal) cycloaddition. Despite their synthetic potential, the widespread adoption of cyclopropanones as substrates has been considerably hampered by the difficulties associated with the preparation and storage of such unstable compounds, prompting the development of cyclopropanone surrogates that can equilibrate to parent ketone in situ via elimination. This review summarizes the syntheses and applications of cyclopropanone derivatives and their equivalents, and offers a perspective of the state of the field as well as its expected future directions.

scholarly journals Fluorinated cyclohexanes: Synthesis of amine building blocks of the all-cis 2,3,5,6-tetrafluorocyclohexylamine motif

2017 ◽  
Vol 13 ◽  
pp. 728-733 ◽  
Author(s):  
Tetiana Bykova ◽  
Nawaf Al-Maharik ◽  
Alexandra M Z Slawin ◽  
David O'Hagan
Keyword(s):  
Methyl Iodide ◽  
Ring Opening ◽  
Building Blocks ◽  
Ring System ◽  
Cyclohexane Ring ◽  
Birch Reduction ◽  
Methyl Group ◽  
Ring Opening Reactions

This paper reports the synthesis of three amine stereoisomers 5a–c of the tetrafluorocyclohexyl ring system, as building blocks for discovery chemistry programmes. The synthesis starts from a Birch reduction of benzonitrile, followed by an in situ methyl iodide quench. The resultant 2,5-cyclohexadiene was progressed via double epoxidations and then hydrofluorination ring opening reactions. The resultant fluorohydrin moieties were then converted to different stereoisomers of the tetrafluorocyclohexyl ring system, and then reductive hydrogenation of the nitrile delivered three amine stereoisomers. It proved necessary to place a methyl group on the cyclohexane ring in order to stabilise the compound against subsequent HF elimination. The two all-cis tetrafluorocyclohexyl isomers 5a and 5b constitute facially polarized cyclohexane rings, with fluorines on the electronegative face and hydrogens on the electropositive face.

Ring expansion and ring opening of 3-halooxindoles with N-alkoxycarbonyl-O-tosylhydroxylamines for divergent access to 4-aminoquinolin-2-ones and N-Cbz-N’-arylureas

2021 ◽  
Author(s):  
Wei-Cheng Yuan ◽  
Jian Zuo ◽  
Shu-Pei Yuan ◽  
Jian-Qiang Zhao ◽  
Zhen-Hua Wang ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Expansion

The reaction of N-alkoxycarbonyl-O-tosylhydroxylamines with indol-2-ones in situ generated from 3-halooxindoles has been developed for divergently accessing 4-aminoquinolin-2-ones and N-Cbz-N’-arylureas in good to excellent yields.

scholarly journals Cobalt-Catalyzed Multisubstituted Allylation of Chelation-Assisted C-H bond of (Hetero)arenes with Cyclopropenes

2021 ◽  
Author(s):  
Kuppan Ramachandran ◽  
Pazhamalai Anbarasan
Keyword(s):  
Organic Synthesis ◽  
Ring Opening ◽  
Highly Strained

Cyclopropenes are highly strained three-membered carbocycle, which offers unique reactivity in organic synthesis. Herein, Cp*CoIII-catalyzed ring-opening isomerization of cyclopropenes to cobalt vinylcarbene has been utilized for the synthesis of multisubstituted...

Electrophilic Ring Opening of Small Heterocycles

Synthesis ◽  
2017 ◽  
Vol 49 (24) ◽  
pp. 5307-5319 ◽  
Author(s):  
Chuan Wang
Keyword(s):  
Ethylene Oxide ◽  
Functional Groups ◽  
Organic Synthesis ◽  
Ring Opening ◽  
Building Blocks ◽  
Nickel Titanium ◽  
Ring Opening Reactions ◽  
Palladium Catalyzed ◽  
Ring Opening Of Epoxides ◽  
Nucleophilic Ring Opening

Small heterocycles, such as epoxides, aziridines, and ox­etanes are among the most useful building blocks in organic synthesis. Through electrophilic ring opening of these molecules, various electrophilic functional groups can be installed, which cannot be achieved via classic nucleophilic ring-opening reactions. In this review, the developments of electrophilic ring opening of small heterocycles are surveyed and organized according to the types of metal promoters.1 Introduction2 Electrophilic Ring Opening of Small Heterocycles Using Stoichiometric Metals2.1 Lithium-Mediated Electrophilic Ring Opening of Epoxides and Oxetanes2.2 Chromium-Mediated Electrophilic Ring Opening of Vinyl Epoxides2.3 Tin-Mediated Electrophilic Ring Opening of Vinyl Epoxides2.4 Samarium-Mediated Electrophilic Ring Opening of Vinyl and Alkynyl Epoxides2.5 Titanium-Mediated Electrophilic Ring Opening of Epoxides2.6 Platinum, Palladium, and Nickel-Mediated Electrophilic Ring Opening of 1,1-Dimethyl Ethylene Oxide3 Catalytic Electrophilic Ring Opening of Small Heterocycles3.1 Titanium-Catalyzed Electrophilic Ring Opening of Epoxides3.2 Palladium-Catalyzed Electrophilic Ring Opening of Vinyl and Alkynyl Small Heterocycles3.3 Iron-Catalyzed Electrophilic Ring Opening of Oxetanes3.4 Scandium-Catalyzed Electrophilic Ring Opening of Vinyl Epoxides3.5 Iridium-Catalyzed Electrophilic Ring Opening of 2-Methyl 2-Vinyl­oxiranes3.6 Nickel-Catalyzed Electrophilic Ring Opening of Epoxides and Aziridines3.7 Nickel–Titanium-Cocatalyzed Electrophilic Ring Opening of Epoxides4 Summary

scholarly journals Ring-Opening of Cyclodextrins: An Efficient Route to Pure Maltohexa-, Hepta-, and Octaoses

Organics ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 287-305
Author(s):  
Matthieu Pélingre ◽  
Dindet Steve-Evanes Koffi Teki ◽  
Jamal El-Abid ◽  
Vincent Chagnault ◽  
José Kovensky ◽  
...  
Keyword(s):  
Functional Groups ◽  
Organic Synthesis ◽  
Ring Opening ◽  
Building Blocks ◽  
Reaction Conditions ◽  
Strong Potential ◽  
Efficient Route ◽  
Biotechnological Processes

Many preparations of maltooligosaccharides have been described in literature, essentially using enzymatic or biotechnological processes. These compounds, derived from starch, are well-known as prebiotic agents. The use of maltohexa-, hepta-, and octaoses as synthons in organic synthesis was also well documented in literature. They can indeed be obtained as single compounds by the cyclodextrins’ ring-opening. This reaction has been studied for many years, varying the protecting and functional groups and the reaction conditions, leading to functionalized oligomaltoses. These compounds are of wide interest in various fields. They have a strong potential as scaffolds for multivalence in chemobiology, as building blocks for the production of biomimetic pseudo-glycopeptides, as well as monomers for the preparation of materials. In view of the importance of these oligomaltoses, this review focuses on the different methodologies allowing access to them via chemical and enzymatic ring-opening of cyclodextrins.

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