scholarly journals Regio- and stereoselective synthesis of new ensembles of diversely functionalized 1,3-thiaselenol-2-ylmethyl selenides by a double rearrangement reaction

2020 ◽  
Vol 16 ◽  
pp. 515-523 ◽  
Author(s):  
Svetlana V Amosova ◽  
Andrey A Filippov ◽  
Nataliya A Makhaeva ◽  
Alexander I Albanov ◽  
Vladimir A Potapov
Keyword(s):  
Nucleophilic Substitution ◽  
Nucleophilic Addition ◽  
Stereoselective Synthesis ◽  
Ring Expansion ◽  
Nucleophilic Attack ◽  
Substitution Reactions ◽  
Ring Contraction ◽  
Rearrangement Reaction ◽  
High Yields ◽  
Alkyl Propiolates

The reaction of 2-(bromomethyl)-1,3-thiaselenole with potassium selenocyanate proceeded via a rearrangement with ring expansion, leading to a six-membered 2,3-dihydro-1,4-thiaselenin-2-yl selenocyanate (kinetic product) which in turn underwent rearrangement with ring contraction to a 1,3-thiaselenol-2-ylmethyl selenocyanate (thermodynamic product). These rearrangements occurred by a nucleophilic attack of the selenocyanate anion at two different carbon atoms of the seleniranium intermediate. The efficient regioselective synthesis of alkyl, allyl, 2-propynyl, benzyl, 4-fluorobenzyl, and 2-pyridinylmethyl 1,3-thiaselenol-2-ylmethyl selenides was developed based on the generation of sodium 1,3-thiaselenol-2-ylmethylselenolate from 1,3-thiaselenol-2-ylmethyl selenocyanate or bis(1,3-thiaselenol-2-ylmethyl) diselenide followed by nucleophilic substitution reactions. Sodium 1,3-thiaselenol-2-ylmethylselenolate underwent nucleophilic addition to alkyl propiolates in a regio- and stereoselective manner affording 1,3-thiaselenol-2-ylmethyl vinyl selenides in high yields predominantly with Z-configuration. Not a single representative of the 1,3-thiaselenol-2-ylmethyl selenide scaffold has been previously described in the literature.

scholarly journals Efficient Synthesis of a New Family of 2,6-Disulfanyl-9-Selenabicyclo[3.3.1]Nonanes

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2849
Author(s):  
Maxim V. Musalov ◽  
Vladimir A. Potapov ◽  
Svetlana V. Amosova
Keyword(s):  
Nucleophilic Substitution ◽  
Nucleophilic Addition ◽  
Triple Bond ◽  
Efficient Synthesis ◽  
New Family ◽  
Stereoselective Addition ◽  
Benzyl Halides ◽  
High Yields ◽  
Derivatives Of ◽  
Alkyl Propiolates

The efficient synthesis of a new family of 2,6-disulfanyl-9-selenabicyclo[3.3.1]nonanes in high yields has been developed based on 9-selenabicyclo[3.3.1]nonane-2,6-dithiolate anion generated from bis-isothiouronium salt of 2,6-dibromo-9-selenabicyclo[3.3.1]nonane. The derivatives of 2,6-disulfanyl-9-selenabicyclo[3.3.1]nonane containing alkyl, allyl and benzyl moieties have been prepared in 90–99% yields by nucleophilic substitution of 9-selenabicyclo[3.3.1]nonane-2,6-dithiolate anion with alkyl, allyl and benzyl halides. The reaction of nucleophilic addition of 9-selenabicyclo[3.3.1]nonane-2,6-dithiolate anion to alkyl propiolates afforded 2,6-di(vinylsulfanyl)-9-selenabicyclo[3.3.1]nonanes. The conditions for regio- and stereoselective addition of 9-selenabicyclo[3.3.1]nonane-2,6-dithiolate anion to a triple bond of alkyl propiolates have been found. To date, not a single representative of 2,6-disulfanyl-9-selenabicyclo[3.3.1]nonanes has been described in the literature.

Stereoselective Synthesis of Multisubstituted α-fluoro-β-lactams

2020 ◽  
Vol 24 (18) ◽  
pp. 2169-2180
Author(s):  
Atsushi Tarui ◽  
Yukiko Karuo ◽  
Kazuyuki Sato ◽  
Kentaro Kawai ◽  
Masaaki Omote
Keyword(s):  
Nucleophilic Substitution ◽  
Substitution Reaction ◽  
Stereoselective Synthesis ◽  
Nucleophilic Substitution Reaction ◽  
Nucleophilic Attack ◽  
Type Reaction ◽  
Lactam Ring ◽  
Metal Catalyzed ◽  
Cyclic Compounds ◽  
Nucleophilic Acyl Substitution

β-Lactams, found in β -lactam antibiotics, are the structurally distorted cyclic compounds being subjected to nucleophilic acyl substitution reaction. α-Fluorination of β -lactams is a simple and expedient approach to control the reactivity of β-lactam ring toward nucleophilic attack, which would hopefully lead to the new design of future antibiotics. From the viewpoint of obtaining multisubstituted α -fluoro-β-lactams, α -bromo-α- fluoro-β-lactams are considered as key compounds for structure functionalization, including nucleophilic substitution reaction, aldol-type reaction and metal-catalyzed crosscoupling reaction. All the reactions can be conducted smoothly to afford a variety of multisubstituted α-fluoro-β-lactams. During the course of the examination, chiral α,α-difluoro- β-lactams and α -bromo-β-fluoro-α-lactams are successfully obtained, which are considered potent precursors for making stereocontrolled multisubstituted α-fluoro-β-lactams.

Pyridinophane Bridging Group Chemistry: Synthesis and Reactions of 1,2,9,10-Tetra-chloro[ 2,2](2,6)pyridinophane-1,9-diene

1979 ◽  
Vol 32 (6) ◽  
pp. 1241 ◽  
Author(s):  
HJJB Martel ◽  
S McMahon ◽  
M Rasmussen
Keyword(s):  
Nucleophilic Addition ◽  
Good Yield ◽  
Substitution Reactions ◽  
Valence Tautomerism ◽  
Vacuum Pyrolysis ◽  
High Yields

Oxidation and polychlorination of 2,11-dithia[3,3](2,6)pyridinophane (II) gives high yields of the corresponding octachloro bissulfone (14) which, on vacuum pyrolysis, readily loses SO2 and Cl2 sequentially, giving eventually a good yield of orange 1,2,9,10-tetrachloro[2,2](2,6)pyridinophane-1,9-diene (4). Nucleophilic addition and substitution reactions of the dichloroethene bridges of (4) are described. None of the [2,2]metacyclophane diene systems undergoes spontaneous or photoinduced valence tautomerism to a 10b,10c-diazapyrene (2).

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>

The unexpected reactivity of 9-iodo-nido-carborane: from nucleophilic substitution reactions to the synthesis of tricobalt tris(dicarbollide) Na[4,4′,4′′-(MeOCH2CH2O)3-3,3′,3′′-Co3(μ3-O)(μ3-S)(1,2-C2B9H10)3]

2021 ◽  
Vol 50 (7) ◽  
pp. 2671-2688
Author(s):  
Marina Yu. Stogniy ◽  
Sergey A. Anufriev ◽  
Akim V. Shmal'ko ◽  
Sergey M. Antropov ◽  
Aleksei A. Anisimov ◽  
...  
Keyword(s):  
Nucleophilic Substitution ◽  
Substitution Reactions ◽  
Nucleophilic Substitution Reactions

An unusual reactivity of 9-iodo-nido-carborane [9-I-7,8-C2B9H11]− towards nucleophiles under strong basic conditions was revealed.

scholarly journals Synthesis and Antiproliferative Activity of Phosphorus Substituted 4-Cyanooxazolines, 2-Aminocyanooxazolines, 2-Iminocyanooxazolidines and 2-Aminocyanothiazolines by Rearrangement of Cyanoaziridines

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4265
Author(s):  
Victor Carramiñana ◽  
Ana M. Ochoa de Ochoa de Retana ◽  
Francisco Palacios ◽  
Jesús M. de los de los Santos
Keyword(s):  
Ring Opening ◽  
Human Lung ◽  
Ring Expansion ◽  
Moderate Activity ◽  
A549 Cell Line ◽  
One Pot ◽  
Acidic Conditions ◽  
Lung Adenocarcinoma A549 ◽  
High Yields

Several phosphorus-substituted N-acylated cyanoaziridines 2 and N-carbamoylated cyanoziridines 5 were prepared in good to high yields. N-Acylated cyanoaziridines 2 were used, after ring expansion, in an efficient synthesis of oxazoline derivative 3a and in a completely regio-controlled reaction in the presence of NaI. Conversely, N-carbamoyl cyanoaziridines 5 reacted with NaI to obtain a regioisomeric mixture of 2-aminocyanooxazolines 7. Mild acidic conditions can be used for the isomerization of N-thiocarbamoyl cyanoaziridine 6a into a 2-aminocyanothiazoline derivative 8a by using BF3·OEt2 as a Lewis acid. Likewise, a one pot reaction of NH-cyanoaziridines 1 with isocyanates obtained 2-iminocyanooxazolidines 9 regioselectively. This synthetic methodology involves the addition of isocyanates to starting cyanoaziridines to obtain N-carbamoyl cyanoaziridines 5, which after the ring opening, reacts with a second equivalent of isocyanate to give the final 2-imino cyanooxazolidines 9. In addition, the cytotoxic effect on the cell lines derived from human lung adenocarcinoma (A549) was also screened. 2-Iminooxazolidines 9 exhibited moderate activity against the A549 cell line in vitro. Furthermore, a selectivity towards cancer cells (A549) over non-malignant cells (MCR-5) was detected.

Sign in / Sign up

Export Citation Format

Share Document