Variability of Rhodium(III)-Catalyzed Reactions of Aromatic Oximes with Alkenes

Synlett ◽  
2020 ◽  
Vol 31 (11) ◽  
pp. 1117-1120 ◽  
Author(s):  
Dmitry S. Perekalin ◽  
Evgeniya A. Trifonova ◽  
Alina A. Komarova ◽  
Denis Chusov
Keyword(s):  
Double Bond ◽  
Functional Groups ◽  
Rhodium Catalyst ◽  
The Other ◽  
Chiral Catalyst ◽  
Enantiomeric Ratio ◽  
Other Hand ◽  
Terminal Alkenes ◽  
Catalyzed Reactions ◽  
Acetophenone Oxime

Acetophenone oxime reacts with various alkenes in the presence of the rhodium catalyst [Cp*RhCl2]2 (2.5 mol%; Cp* = pentamethylcyclopentadienyl) and 1,1,1,3,3,3-hexafluoropropan-2-ol as an important cosolvent. Styrene, aliphatic terminal alkenes, and strained cyclic alkenes gave the corresponding substituted dihydroisoquinolines in yields of 50–99%. On the other hand, alkenes containing functional groups close to the double bond gave a variety of different products. The reactions of acetophenone oxime with styrene or dec-1-ene in the presence of the chiral catalyst [(C5H2 t Bu2CH2 t Bu)RhI2]2 provided the corresponding dihydroisoquinolines with improved regioselectivity but a low enantiomeric ratio (61:39 in both cases).

Covalent Addition of Bisulfite Ion to N-Alkylated Uracils and Thiouracils

1979 ◽  
Vol 32 (3) ◽  
pp. 545 ◽  
Author(s):  
IH Pitman ◽  
NB Jain
Keyword(s):  
Double Bond ◽  
Equilibrium Constants ◽  
The Other ◽  
Small Reduction ◽  
Other Hand ◽  
Alkyl Substitution ◽  
Covalent Adduct ◽  
Covalent Adducts

Rate and equilibrium constants at 25� and I 1.0 M have been calculated for the covalent additon of bisulfite ion across the C6=C5 double bond of uracil, 1-methyluracil, 1,3-dimethyluracil, uridine, uridine-5'-diphosphate (dianion), adenylyl(3'-5')uridine, uridylyl(3'-5')adenosine, 2-thiouracil and 1,3-dimethyl-2-thiouracil. Substitution of either uncharged (e.g. ribose) or charged (e.g. ribose 5'-diphosphate dianion) groups for the N1 proton of uracil resulted in a small reduction in both the rate and equilibrium constants for the formation of the adduct but had very little effect on the rate of elimination of bisulfite ion from the adduct. On the other hand, substitution at N3 of uracil substantially reduced both the rates of formation and decomposition of the covalent adduct. The rates of formation of the covalent adducts of 2-thiouracils were faster than those of the uracil adducts but alkyl substitution produced similar decreases in the magnitudes of rate and equilibrium constants.

Pd-Catalyzed Domino Reactions Involving Alkenes To Access Substituted Indole Derivatives

Synthesis ◽  
2020 ◽  
Vol 52 (19) ◽  
pp. 2731-2760
Author(s):  
Egle M. Beccalli ◽  
Michael S. Christodoulou ◽  
Francesca Foschi ◽  
Sabrina Giofrè
Keyword(s):  
Double Bond ◽  
The Other ◽  
Indole Derivatives ◽  
Domino Reactions ◽  
Recent Advances ◽  
Other Hand ◽  
Palladium Catalyzed ◽  
Intermolecular Reactions

Palladium-catalyzed domino reactions are advanced tools in achieving various nitrogen-containing heterocycles in an efficient and economical manner due to the reduced number of steps in the process. This review highlights recent advances in domino processes aimed at the synthesis of indole derivatives and polycyclic systems containing the indole nucleus in intra/intra- or intra/intermolecular reactions. In particular, we consider domino processes that involve a double bond in a step of the sequence, which allow the issue of regioselectivity in the cyclization to be faced and overcome. The different sections in this review focus on the synthesis of the indole nucleus and functionalization of the scaffold starting from different substrates that have been identified as activated starting materials, which involve a halogenated moiety or unactivated unsaturated systems. In the former case, the reaction is under Pd(0) catalysis, and in the second case a Pd(II) catalytic species is required and then an oxidant is necessary to reconvert the Pd(0) into the active Pd(II) species. On the other hand, the second method has the advantage that it uses easy available and inexpensive substrates.1 Introduction2 Indole Scaffold Synthesis2.1 Activated Substrates2.2 Unactivated Substrates3 Functionalization of Indole Scaffold3.1 Activated Substrates3.2 Unactivated Substrates4 Conclusions

scholarly journals Сharms and spells from a dislocation in the oral tradition of the Middle Irtysh region

2019 ◽  
pp. 26-32
Author(s):  
V. A. Moskvina
Keyword(s):  
Functional Groups ◽  
Oral Tradition ◽  
The Body ◽  
The Other ◽  
Structural Elements ◽  
Other Hand ◽  
The One ◽  
The Way

The article deals with the spells of one functional-thematic group recorded in the Middle Irtysh region. The features of existence of these spells in the regional tradition of the Middle Irtysh region and versification of their plots are re- vealed. The prevalence of spells in cause of a wrench in the two Northern districts of Omsk region is caused by the settle- ment of Belarusians in these places in the late XIX – early XX centuries. This suggests that the place of the exodus tra- dition of the spells from a wrench is in Belarus. The analysis of the plots of these spells confirms this assumption. The method of examining the Siberian plots is based on the systematization of structural elements of plots proposed by T. A. Agapkina and A. L. Toporkov which researchers call episodes. The article compares the episodes of the second Mersebourg spell in Belarusian spells with Siberian texts. The comparison shows that the language of this spells being subjected to Russification. On the one hand, this leads to the loss of some motives and formulas, i.e. the violation of the integrity of the plot, on the other hand, the rhythm of the text is enhanced, the rhyme appears. These processes open the way to the penetration of verbal components from other functional groups into the considered spells. As the result, one can observe the extension of ideas that this disease is not necessarily associated with the violation of integrity of the body.

From phosphatriafulvenes to phosphabenzenes and stable six-membered phosphaallenes

2000 ◽  
Vol 72 (9) ◽  
pp. 1769-1772 ◽  
Author(s):  
Michael A. Hofmann ◽  
Uwe Bergsträßer ◽  
Manfred Regitz
Keyword(s):  
Double Bond ◽  
Phosphorus Atom ◽  
The Other ◽  
Dipolar Cycloaddition ◽  
Other Hand ◽  
The One

Phosphatriafulvenes readily react with kinetically stabilized phosphaalkynes. Depending on the substituent at the phosphorus atom of the phosphatriafulvene, different six-membered phosphaheterocycles can be isolated. On the one hand, 1,3-diphosphabenzenes are formed, which can be isomerized thermally to diphospha dewarbenzenes or complexed by Cr(CO)3. On the other hand, 1,3-diphosphaisobenzenes are thus available. They are converted to bicyclic six-membered allenes via 1,3-dipolar cycloaddition to the P/C double bond.

OPTICAL PROPERTIES OF FUNCTIONALIZED POLYTHIOPHENES

2005 ◽  
Vol 19 (32) ◽  
pp. 4645-4676 ◽  
Author(s):  
N. SOMANATHAN ◽  
S. RADHAKRISHNAN
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Functional Groups ◽  
Thiophene Ring ◽  
Point Of View ◽  
The Other ◽  
Emission Characteristics ◽  
Polymeric Structure ◽  
Other Hand

This review focuses on the interrelation between the influences of polymeric structure on the optical properties of polythiophene — a versatile polymer for opto-electronic applications. From the application's point of view, the polymer should either be melt- or solution-processible. Functionalization of polythiophenes really helps for the above. On the other hand, the functionalization at the 3 and/or 4 position of the thiophene ring modifies the band gap of the polymer, which in turn, modifies photo absorption, photo- and electro-emission characteristics of polythiophenes. The present work reviews the influence of the optical properties of polythiophene on the different functional groups present in the thiophene ring.

Photoimaging Materials Based on Base-amplifying Silicone Resins Having Phenylsulfonylethyl Groups

2006 ◽  
Vol 961 ◽  
Author(s):  
Satoru Inoue ◽  
Koji Arimitsu ◽  
Takahiro Gunji ◽  
Yoshimoto Abe ◽  
Kunihiro Ichimura
Keyword(s):  
Uv Curing ◽  
Exposure Dose ◽  
The Other ◽  
Secondary Amines ◽  
Quantum Yields ◽  
Amino Groups ◽  
Other Hand ◽  
Primary Amino ◽  
Secondary Amino ◽  
Catalyzed Reactions

ABSTRACTRecently, the large number of investigations concerning acid-catalyzed photopolymer systems such as chemically amplified photoresists and UV-curing materials has been reported. On the other hand, analogous systems utilizing base-catalyzed reactions have received far less attention, because low quantum yields for photobase generation to lead to low photosensitivity of these systems. To improve this problem, we proposed introduction of the concept of base proliferation reactions into the photopolymer systems using base-catalyzed reactions. The concept involves the autocatalytic base-catalyzed decomposition of a compound, referred to as a base amplifier which releases a newborn amine, leading to its autocatalytic decomposition. In fact, the addition of the base amplifiers such as 9-fluorenylmethyl carbamate, phenylsulfonylethyl carbamate, and 3-nitropentane-2-yl carbamate to a photopolymer consisting of an epoxy polymer sensitized and a photobase generator (PBG) resulted in the marked improvement of photosensitivity.However, these base amplifiers with low molecular weight are not suitable for photopatterning because of the volatility and the excessive diffusion of amines proliferated in polymer films. We report here novel base-amplifying silicone resins tethering phenylsulfonylethyl carbamoyl groups which proliferate primary amino groups or secondary amino groups in their side chains.Base-catalyzed decomposition behavior of films of these resins containing PBG was evaluated by UV absorption measurements. A film consisting of the resin proliferating primary amino groups and 10 wt% of PBG decomposed immediately in a nonlinear manner by 365 nm irradiation and subsequent heat treatment at 120oC for 6 min. On the other hand, this film without UV irradiation was thermally stable for 18 min at 120oC. These results indicate that photoinduced base proliferation reaction of the resin proceeded. A film consisting of the resin generating secondary amino groups and PBG decomposed in a way similar to that of the resin proliferating primary amino groups. Furthermore, lithographic evaluation of the film comprising the resin to generate secondary amines and PBG obtained 7ÊS positive images with an exposure dose of 75 mJ/cm2 which shows higher sensitivity when compared to conventional base-catalyzed photopolymers.

Boron Trifluoride Mediated Addition of Nucleophiles to endo- and exo-Substituted Norbornene Derivatives

2004 ◽  
Vol 59 (1) ◽  
pp. 109-118
Author(s):  
Alper İşleyen ◽  
Tuğmac Sayraç ◽  
Özdemir Doğan
Keyword(s):  
Double Bond ◽  
Boron Trifluoride ◽  
Substituent Effects ◽  
The Other ◽  
Other Hand ◽  
Regioselective Addition ◽  
Remote Substituent ◽  
Norbornene Derivatives

Abstract Remote substituent effects on the regioselectivity and stereoselectivity in the boron trifluoride mediated addition of nucleophiles (iodide and bromide) to endo- and exo-2-substituted norbornene derivatives have been investigated. The main products of the reactions resulted from the regioselective addition of nucleophiles to the double bond of norbornene derivatives. Products resulting from the Wagner-Meerwein type rearrangement were also isolated in considerable amounts. All of the reactions gave the addition products in reasonably good yields with high regioselectivity. The endo/exo selectivity, on the other hand, changed depending on the nucleophile and the substrate.

scholarly journals Biocidal Amidic Natural Products

2008 ◽  
Vol 3 (11) ◽  
pp. 1934578X0800301
Author(s):  
Vernon G. S. Box
Keyword(s):  
Natural Products ◽  
Molecular Modeling ◽  
Functional Groups ◽  
Structural Features ◽  
The Other ◽  
Potential Toxicity ◽  
Other Hand ◽  
Biocidal Properties

Some of the more potent, and interesting, natural products that have marked biocidal properties have one, or more, amide functional groups. On the other hand, there are countless amides that are non-toxic. Thus, there is a need to try to identify the structural features of biocidal amides that could indicate their potential toxicity. A review of the structures of some of these toxic amides, using the molecular modeling program STR3DI32, has established that these amide groups are non-delocalized.

Recent Advances in Radical Nitration Using tert-Butyl Nitrite

Synthesis ◽  
2020 ◽  
Vol 52 (06) ◽  
pp. 796-806 ◽  
Author(s):  
Si-Zhe Song ◽  
Youren Dong ◽  
Guo-Ping Ge ◽  
Qiang Li ◽  
Wen-Ting Wei
Keyword(s):  
Functional Groups ◽  
Reaction Mechanisms ◽  
Nitro Compounds ◽  
The Other ◽  
Tert Butyl ◽  
Mild Conditions ◽  
Recent Advances ◽  
Other Hand ◽  
The One

Nitro compounds serve as valuable intermediates for pharmaceuticals, agrochemicals, dyes, and polymers. In recent years, radical nitration using tert-butyl nitrite (t-BuONO) has attracted wide attention and desirable progress has been made. On the one hand, t-BuONO is a potential active nitro radical source and can react with various functional groups. On the other hand, as a green and novel nitration reagent, t-BuONO has relatively low price and can easily produce a radical under mild conditions, which undoubtedly provides a simple and efficient way for nitration reactions. To date, some important reviews are available that summarize the synthesis of nitro compounds. To the best of our knowledge, however, there is still no review that exclusively discusses the synthesis of nitro compounds using t-BuONO through a radical strategy. Therefore, this review aims to highlight the recent advances in radical nitration using t-BuONO as nitration reagent. The main progress in this area has been presented according to the type of reaction substrates. Special attention has been paid discussion of the reaction mechanisms and selected examples of substrates have been given. We hope this paper will be a useful reference and inspiration for those who are exploring the synthesis of nitro compounds using t-BuONO.1 Introduction2 Radical Nitration of Alkenes3 Radical Nitration of Aromatics4 Radical Nitration of Alkynes5 Radical Nitration of 1,n-Enynes6 Radical Nitration of Alkanes7 Summary and Perspective

scholarly journals Site Selectivity in Pd-Catalyzed Reactions of α-Diazo-α-(methoxycarbonyl)acetamides: Effects of Catalysts and Substrate Substitution in the Synthesis of Oxindoles and β-Lactams

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3551 ◽  
Author(s):  
Daniel Solé ◽  
Ferran Pérez-Janer ◽  
Arianna Amenta ◽  
M.-Lluïsa Bennasar ◽  
Israel Fernández
Keyword(s):  
Dft Calculations ◽  
Reaction Mechanisms ◽  
The Other ◽  
Oxidation States ◽  
Other Hand ◽  
Site Selectivity ◽  
Catalyst Type ◽  
Catalyzed Reactions ◽  
Insight Into

The Pd-catalyzed intramolecular carbene C–H insertion of α-diazo-α-(methoxycarbonyl)acetamides to prepare oxindoles as well as β-lactams was studied. In order to identify what factors influence the selectivity of the processes, we explored how the reactions are affected by the catalyst type, using two oxidation states of Pd and a variety of ligands. It was found that, in the synthesis of oxindoles, ((IMes)Pd(NQ))2 can be used as an alternative to Pd2(dba)3 to catalyze the carbene CArsp2–H insertion, although it was less versatile. On the other hand, it was demonstrated that the Csp3–H insertion leading to β-lactams can be effectively promoted by both Pd(0) and Pd(II) catalysts, the latter being most efficient. Insight into the reaction mechanisms involved in these transformations was provided by DFT calculations.

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