scholarly journals Steric and Polar Factors Affecting Heteroring Opening of 2-[2-carboxy-3,4,5,6-tetrachloro]phenyl-4H-3,1-Benzoxazin-4-one by Nitrogen and Carbon Nucleophiles

2009 ◽  
Vol 5 (2) ◽  
pp. 661-668
Author(s):  
Jehan Mahmoud Morsy ◽  
Maher Abdel Aziz El-Hashash
Keyword(s):  
Ring Opening ◽  
Reaction Conditions ◽  
Factors Affecting ◽  
Carbon Nucleophiles ◽  
Nitrogen Nucleophiles

The behavior of 2-[2-carboxy-3,4,5,6-tetrachloro]phenyl-4H-3,1-Benzoxazin-4-  one towards Nitrogen nucleophiles and Carbon nucleophiles under Friedel–Crafts' reaction conditions has been investigated and steric versus polar factors affecting ring opening has been studied.

scholarly journals Ring-Opening Copolymerization of Cyclohexene Oxide and Cyclic Anhydrides Catalyzed by Bimetallic Scorpionate Zinc Catalysts

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1651
Author(s):  
Felipe de la Cruz-Martínez ◽  
Marc Martínez de Sarasa Buchaca ◽  
Almudena del Campo-Balguerías ◽  
Juan Fernández-Baeza ◽  
Luis F. Sánchez-Barba ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Reaction Mechanism ◽  
Catalytic System ◽  
Phthalic Anhydride ◽  
Ring Opening ◽  
High Selectivity ◽  
Zinc Complexes ◽  
Cyclohexene Oxide ◽  
Reaction Conditions ◽  
Cyclic Anhydrides

The catalytic activity and high selectivity reported by bimetallic heteroscorpionate acetate zinc complexes in ring-opening copolymerization (ROCOP) reactions involving CO2 as substrate encouraged us to expand their use as catalysts for ROCOP of cyclohexene oxide (CHO) and cyclic anhydrides. Among the catalysts tested for the ROCOP of CHO and phthalic anhydride at different reaction conditions, the most active catalytic system was the combination of complex 3 with bis(triphenylphosphine)iminium as cocatalyst in toluene at 80 °C. Once the optimal catalytic system was determined, the scope in terms of other cyclic anhydrides was broadened. The catalytic system was capable of copolymerizing selectively and efficiently CHO with phthalic, maleic, succinic and naphthalic anhydrides to afford the corresponding polyester materials. The polyesters obtained were characterized by spectroscopic, spectrometric, and calorimetric techniques. Finally, the reaction mechanism of the catalytic system was proposed based on stoichiometric reactions.

N-Chlorinative Ring Contraction of 1,4-Dimethoxyphthalazines via a Bicyclization/Ring-Opening Mechanism

Synthesis ◽  
2020 ◽  
Author(s):  
Jeong Kyun Im ◽  
Ilju Jeong ◽  
Jun-Ho Choi ◽  
Won-jin Chung ◽  
ByeongDo Yang ◽  
...  
Keyword(s):  
Ring Opening ◽  
Reaction Conditions ◽  
Ring Contraction ◽  
Silyl Group ◽  
Favorskii Rearrangement ◽  
Mechanistic Analysis ◽  
Group A ◽  
Overall Efficiency ◽  
Trichloroisocyanuric Acid

AbstractAn unprecedented N-chlorinative ring contraction of 1,2-diazines was discovered and investigated with an electrophilic chlorinating reagent, trichloroisocyanuric acid (TCICA). Through optimization and mechanistic analysis, the assisting role of n-Bu4NCl as an exogenous nucleophile was identified, and the optimized reaction conditions were applied to a range of 1,4-dimethoxyphthalazine derivatives. Also, an improvement of overall efficiency was demonstrated by the use of a labile O-silyl group. A bicyclization/ring-opening mechanism, inspired by the Favorskii rearrangement, was proposed and supported by the DFT calculations. Furthermore, the efforts on scope expansion as well as the evaluation of other electrophilic promoters revealed that the newly developed ring contraction reactivity is a unique characteristic of 1,4-dimethoxyphthalazine scaffold and TCICA.

Ring-opening Addition Reactions of 1-tert-Butoxycarbonyl-3,4- epoxypiperidine with Amine Nucleophiles

2010 ◽  
Vol 65 (2) ◽  
pp. 197-202 ◽  
Author(s):  
Boja Poojary ◽  
Lim Hee-Jong
Keyword(s):  
Ring Opening ◽  
Addition Reactions ◽  
Reaction Conditions ◽  
Different Types

Ring-opening addition reactions of 1-tert-butoxycarbonyl-3,4-epoxypiperidine leading to the formation of the corresponding regioisomeric trans-β -aminoalcohols were carried out with three different types of amine nucleophiles under different reaction conditions with a view to study the reactivity and regioselectivity.

Régiosélectivité d'additions de nucléophiles sur des dialkoxycarbonyle quinoxalinotropones

1983 ◽  
Vol 61 (8) ◽  
pp. 1806-1812 ◽  
Author(s):  
Alain Turck ◽  
Roland Boutte ◽  
Guy Quéguiner
Keyword(s):  
Sodium Methoxide ◽  
Carbon Nucleophiles ◽  
Ethyl Malonate ◽  
Nitrogen Nucleophiles ◽  
Substituted Hydrazines

We have studied the regioselectivity of Michael type additions on tropones attached to quinoxalines, i.e. dialkoxycarbonyl quinoxalinotropones. We used carbon nucleophiles (ethyl malonate and malononitrile), oxygen nucleophiles (sodium methoxide), sulphur nucleophiles (methyl and benzyl mercaptans), and nitrogen nucleophiles (methyl and phenylhydrazine, aniline). We have shown that, in general, these reactions lead to 1,4-monoadditions or to bridged products arising from a bis-1,4-addition process. We have determined the structures of the complexes obtained by comparison to the work of Fohlisch etal. in the homoaromatic series. For the case of substituted hydrazines, we present some evidence on the rearrangement mechanisms proposed by these authors. [Journal translation]

Regioselective ring opening of thiomalic acid anhydrides by carbon nucleophiles. Synthesis and X-ray structure elucidation of novel thiophenone derivatives

Tetrahedron ◽  
2009 ◽  
Vol 65 (18) ◽  
pp. 3711-3716 ◽  
Author(s):  
Stefanos Kikionis ◽  
Vickie McKee ◽  
John Markopoulos ◽  
Olga Igglessi-Markopoulou
Keyword(s):  
Ring Opening ◽  
Structure Elucidation ◽  
X Ray ◽  
Carbon Nucleophiles ◽  
Acid Anhydrides

Cycloaddition reactions. Addition of dimethyl acetylenedicarboxylate to 1-dimethylaminoindene

1970 ◽  
Vol 48 (11) ◽  
pp. 1633-1638 ◽  
Author(s):  
Terrence W. Doyle
Keyword(s):  
Ring Opening ◽  
Cycloaddition Reactions ◽  
Dimethyl Acetylenedicarboxylate ◽  
Reaction Conditions

The cycloaddition of 1-dimethylaminoindene (2) to dimethyl acetylenedicarboxylate to form a fused cyclobutene system 3 is discussed. Compound 3 underwent two modes of ring opening to yield either the indene–maleate system 4 or the benzocycloheptatriene system 5 depending on reaction conditions. The synthesis of a number of multifunctional benzotropones from 5 is discussed.

scholarly journals Rapid transformation of sulfinate salts into sulfonates promoted by a hypervalent iodine(III) reagent

2018 ◽  
Vol 14 ◽  
pp. 1203-1207 ◽  
Author(s):  
Elsa Deruer ◽  
Vincent Hamel ◽  
Samuel Blais ◽  
Sylvain Canesi
Keyword(s):  
Ring Opening ◽  
Hypervalent Iodine ◽  
Cyclic Ethers ◽  
Reaction Conditions ◽  
Alternative Method ◽  
Aromatic Systems ◽  
Mediated Oxidation ◽  
Rapid Transformation

An alternative method for forming sulfonates through hypervalent iodine(III) reagent-mediated oxidation of sodium sulfinates has been developed. This transformation involves trapping reactive sulfonium species using alcohols. With additional optimization of the reaction conditions, the method appears extendable to other nucleophiles such as electron-rich aromatic systems or cyclic ethers through a ring opening pathway.

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