scholarly journals Vinylphosphonium and 2-aminovinylphosphonium salts – preparation and applications in organic synthesis

2017 ◽  
Vol 13 ◽  
pp. 2710-2738 ◽  
Author(s):  
Anna Kuźnik ◽  
Roman Mazurkiewicz ◽  
Beata Fryczkowska

The main synthetic routes towards vinylphosphonium salts and their wide applications in organic synthesis are discussed in this review. Particular attention is paid to the use of these compounds as building blocks for the synthesis of carbo- and heterocyclic systems after their prior transformation into the corresponding phosphorus ylides, followed by the intramolecular Wittig reaction with various types of nucleophiles containing a carbonyl function in their structures.

2020 ◽  
Vol 17 (3) ◽  
pp. 297-308
Author(s):  
Nidhi Singh ◽  
Jaya Pandey

: Henry reaction is an important reaction employing carbonyls which furnishes β-nitro alcohol, nitroalkene, α-nitro ketones, β-amino alcohol as products and byproducts that may be transfigured as building blocks for other synthetic reactions. This paper focuses on various synthetic routes for Henry reaction, a versatile reaction of high significance in organic synthesis. The paper discusses the chemistry and plausible products of the reaction, along with the various available synthetic routes for the same, ranging from classical conventional methods to modern methods of green chemistry trends. Use of various catalysts as rate enhancer as well as use of various catalysts as enantioselective frontman for stereoselective reactions, have been described in this work.


1977 ◽  
Vol 55 (12) ◽  
pp. 2442-2449 ◽  
Author(s):  
John M. McIntosh ◽  
Richard S. Steevensz

The preparation of a series of vinyltriphenylphosphonium salts, all of which bear a substituent on the carbon attached to phosphorus, is described. Yields are generally poor unless a symmetrical secondary allylic halide can be used. The use of these salts in the preparation of substituted 2,5-dihydrothiophenes has been examined. In general, reaction times are increased and product yields decreased relative to the reactions of the unsubstituted salts previously reported. This result is ascribed to steric inhibition of the intramolecular Wittig reaction.


2002 ◽  
Vol 2002 (9) ◽  
pp. 465-466 ◽  
Author(s):  
Abbas Ali Esmaeili ◽  
Hajar Kheybari

The addition of a dialkyl acetylenedicarboxylate to 3-chloroindole-2-carboxaldehyde in the presence of triphenylphosphine leads initially to a vinylphosphonium salt, which undergoes an intramolecular Wittig reaction to produce the title compounds in fairly good yields.


2019 ◽  
Author(s):  
De-Wei Gao ◽  
Yang Gao ◽  
Huiling Shao ◽  
Tian-Zhang Qiao ◽  
Xin Wang ◽  
...  

Enantioenriched <i>α</i>-aminoboronic acids play a unique role in medicinal chemistry and have emerged as privileged pharmacophores in proteasome inhibitors. Additionally, they represent synthetically useful chiral building blocks in organic synthesis. Recently, CuH-catalyzed asymmetric alkene hydrofunctionalization has become a powerful tool to construct stereogenic carbon centers. In contrast, applying CuH cascade catalysis to achieve reductive 1,1-difunctionalization of alkynes remains an important, but largely unaddressed, synthetic challenge. Herein, we report an efficient strategy to synthesize <i>α</i>-aminoboronates <i>via </i>CuH-catalyzed hydroboration/hydroamination cascade of readily available alkynes. Notably, this transformation selectively delivers the desired 1,1-heterodifunctionalized product in favor of alternative homodifunctionalized, 1,2-heterodifunctionalized, or reductively monofunctionalized byproducts, thereby offering rapid access to these privileged scaffolds with high chemo-, regio- and enantioselectivity.<br>


2020 ◽  
Vol 24 (21) ◽  
pp. 2475-2497
Author(s):  
Andrea Verónica Rodríguez-Mayor ◽  
German Jesid Peralta-Camacho ◽  
Karen Johanna Cárdenas-Martínez ◽  
Javier Eduardo García-Castañeda

Glycoproteins and glycopeptides are an interesting focus of research, because of their potential use as therapeutic agents, since they are related to carbohydrate-carbohydrate, carbohydrate-protein, and carbohydrate-lipid interactions, which are commonly involved in biological processes. It has been established that natural glycoconjugates could be an important source of templates for the design and development of molecules with therapeutic applications. However, isolating large quantities of glycoconjugates from biological sources with the required purity is extremely complex, because these molecules are found in heterogeneous environments and in very low concentrations. As an alternative to solving this problem, the chemical synthesis of glycoconjugates has been developed. In this context, several methods for the synthesis of glycopeptides in solution and/or solid-phase have been reported. In most of these methods, glycosylated amino acid derivatives are used as building blocks for both solution and solid-phase synthesis. The synthetic viability of glycoconjugates is a critical parameter for allowing their use as drugs to mitigate the impact of microbial resistance and/or cancer. However, the chemical synthesis of glycoconjugates is a challenge, because these molecules possess multiple reaction sites and have a very specific stereochemistry. Therefore, it is necessary to design and implement synthetic routes, which may involve various protection schemes but can be stereoselective, environmentally friendly, and high-yielding. This review focuses on glycopeptide synthesis by recapitulating the progress made over the last 15 years.


2019 ◽  
Vol 23 (19) ◽  
pp. 2102-2121
Author(s):  
Hiroyuki Kawafuchi ◽  
Lijian Ma ◽  
Md Imran Hossain ◽  
Tsutomu Inokuchi

O-Acylated 2,2,6,6-tetramethylpiperidine-N-oxyls (abbr. O-AcylTEMPOs) are easily available and stable carboxylic derivatives, but their utility in organic synthesis is unexplored in contrast to analogues, such as the N-methoxy-N-methylamides, known as Weinreb amides. Especially, the O–N unit of the O-acylTEMPOs dictates a fairly electronwithdrawing character for the carbonyl function. This enhances the reactivity and stability of the resulting enolate ions. Accordingly, O-acylTEMPOs allow various transformations and this review encompasses seven topics: (1) Reactivity of O-acylTEMPOs towards nucleophiles and chemoselective transformations, (2) Reactivity of anionic species derived from O-acylTEMPOs, (3) E-Selective Knoevenagel condensation of acetoacetylTEMPOs and synthesis of furans, (4) Electrocyclization of 2,4-dienones derived from acetoacetic derivatives and 2-substituted enals, (5) Diastereoselective addition of amide anion to O-(2-alkenoyl)TEMPOs and &#946;-amino acid synthesis, (6) Thermolysis of O-acylTEMPOs, and (7) Applications for Umpolung reactions using O-benzoylTEMPOs, useful for the electrophilic amination of alkenes and alkynes.


2020 ◽  
Vol 17 (7) ◽  
pp. 540-547
Author(s):  
Chun-Hui Yang ◽  
Cheng Wu ◽  
Jun-Ming Zhang ◽  
Xiang-Zhang Tao ◽  
Jun Xu ◽  
...  

Background: The sulfinic esters are important and useful building blocks in organic synthesis. Objective: The aim of this study was to develop a simple and efficient method for the synthesis of sulfinic esters. Materials and Methods: Constant current electrolysis from thiols and alcohols was selected as the method for the synthesis of sulfinic esters. Results and Discussion: A novel electrochemical method for the synthesis of sulfinic esters from thiophenols and alcohols has been developed. Up to 27 examples of sulfinic esters have been synthesized using the current methods. This protocol shows good functional group tolerance as well as high efficiency. In addition, this protocol can be easily scaled up with good efficiency. Notably, heterocycle-containing substrates, including pyridine, thiophene, and benzothiazole, gave the desired products in good yields. A plausible reaction mechanism is proposed. Conclusion: This research not only provides a green and efficient method for the synthesis of sulfinic esters but also shows new applications of electrochemistry in organic synthesis. It is considered that this green and efficient synthetic protocol used to prepare sulfinic esters will have good applications in the future.


1999 ◽  
Vol 23 (8) ◽  
pp. 512-513
Author(s):  
Issa Yavari ◽  
Farahnaz Nourmohammadian

Tetraalkyl cyclobutene-1,2,3,4-tetracarboxylates, prepared by intramolecular Wittig reaction between a vinylphosphonium salt and diethyl 2-oxobutanedioate, undergo electrocyclic ring-opening reactions, in boiling toluene, to produce highly electron-deficient 1,3-dienes.


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