An unusual tert-butylamine mediated conversion of 6-aryl-7-formyl-2,4,5,8-tetrahydro-1,3-dioxa-5-azocines to 1,2,3,6-tetrahydropyrimidine derivatives

1990 ◽  
Vol 55 (10) ◽  
pp. 2502-2509 ◽  
Author(s):  
Ladislav Štibrányi ◽  
Lubor Fišera ◽  
Rastislav Káčer ◽  
Vladimír Oremus ◽  
Martina Mihulová
Keyword(s):  
Membered Ring ◽  
Dipolar Cycloaddition ◽  
Reaction Sequence ◽  
Pyrimidine Derivatives ◽  
Reaction Conditions ◽  
Photochemical Rearrangement ◽  
Tert Butylamine

An unexpected contraction of the 8-membered ring to a 6-membered one occurring when 6-aryl-7-formyl-2,4,5,8-tetrahydro-1,3-dioxa-5-azocines II were treated with tert-butylamine afforded 4-aryl-5-formyl-1-(1,1-dimethylethyl)-1,2,3,6-tetrahydropyrimidines III. Reaction conditions for the photorearrangement of chlorophenyl-substituted condensed isoxazolines I to II were worked out. The reaction sequence: 1,3-dipolar cycloaddition, photochemical rearrangement, treatment with tert-butylamine constitutes a new route to pyrimidine derivatives from 2H,4H,7H-1,3-dioxepine.

Synthesis and characterization of functional six-membered ring carbonates for the preparation of orthogonal couplers

e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Thorsten Anders ◽  
Helmut Keul ◽  
Martin Möller
Keyword(s):  
Membered Ring ◽  
Surface Coatings ◽  
Dipolar Cycloaddition ◽  
Ambient Conditions ◽  
Reaction Conditions ◽  
Ring Opening Reaction ◽  
Coupling Principle ◽  
Multifunctional Polymers ◽  
Nucleophilic Ring Opening

Abstract On the basis of commercially available trimethylolpropane (TMP) three six-membered ring carbonates were prepared, substituted with reactive side groups: a chloroformate (2a), an imidazolyl carbamate (2b) and a phenyl carbonate (2c). Their synthesis and characterizations are described and compared to known ring carbonates with reactive side groups. Starting from 2a-c orthogonal couplers 3a and 3b were synthesized for conversion under mild reaction conditions. In a model reaction 2-azidoethyl 2-N-acetylamino-2-deoxy- -D-glucopyranose and tertbutyl- N-(3-aminopropyl) carbamate were linked with coupler 3a via a 1,3-dipolar cycloaddition and a nucleophilic ring-opening reaction. This coupling principle can be used for the preparation of multifunctional polymers or surface coatings at ambient conditions.

Derivatives of tetrahydro-2H-pyridine from photorearranged cycloadducts of nitrile oxides

1990 ◽  
Vol 55 (2) ◽  
pp. 512-523 ◽  
Author(s):  
Lubor Fišera ◽  
Vladimír Ondruš ◽  
Hans-Joachim Timpe
Keyword(s):  
Reaction Mechanism ◽  
Double Bond ◽  
Quantum Yields ◽  
Dipolar Cycloaddition ◽  
Mercury Lamp ◽  
Reaction Sequence ◽  
Nitrile Oxides ◽  
Photochemical Rearrangement ◽  
Benzene Rings ◽  
Derivatives Of

1,3-Dipolar cycloaddition of methoxycarbonylnitrile, furannitrile and substituted benzene nitrile oxides (X = 4-CH3, 4-OCH3, 3-OCH3, 4-Cl, 3-Cl, 2,4-diCl, 4-F) to dimethyl 7-(diphenylmethylene)bicyclo[2.2.1]hept-2-ene-5,6-dicarboxylate (XII) led exclusively to exo cycloadducts IV, on irradiation with a low-pressure mercury lamp afforded the required 4-substituted derivatives of dimethyl 2,2-diphenyl-5-formyl-3-azabicyclo[4.3.0]nona-4,9-diene-7,8-dicarboxylate (XI) as sole products. Selectivity of the photorearrangement of isoxazolines IV to enaminoaldehydes XI is due to a stabilization of the biradical VII by the overlap of the radical-electron with π-electrons of the C=C double bond and by two benzene rings. Quantum yields of the photorearrangement, established from the deficit of the starting IV, were found to be greater than those for the analogous oxabicyclic derivatives XVI. The reaction mechanism is proposed and the dependence on various solvents is pointed out; this reaction sequence, viz. the 1,3-dipolar cycloaddition followed by a photochemical rearrangement provides a new method for obtaining derivatives of tetrahydro-2H-pyridine from the well available cyclopentadiene.

scholarly journals Modified Nucleosides, Nucleotides and Nucleic Acids via Click Azide-Alkyne Cycloaddition for Pharmacological Applications

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3100
Author(s):  
Daniela Perrone ◽  
Elena Marchesi ◽  
Lorenzo Preti ◽  
Maria Luisa Navacchia
Keyword(s):  
Cancer Therapy ◽  
Nucleic Acids ◽  
Click Chemistry ◽  
Nucleoside Analogs ◽  
Modified Nucleosides ◽  
Biological Molecules ◽  
Dipolar Cycloaddition ◽  
Virus Diseases ◽  
Reaction Conditions ◽  
Hybrid Compounds

The click azide = alkyne 1,3-dipolar cycloaddition (click chemistry) has become the approach of choice for bioconjugations in medicinal chemistry, providing facile reaction conditions amenable to both small and biological molecules. Many nucleoside analogs are known for their marked impact in cancer therapy and for the treatment of virus diseases and new targeted oligonucleotides have been developed for different purposes. The click chemistry allowing the tolerated union between units with a wide diversity of functional groups represents a robust means of designing new hybrid compounds with an extraordinary diversity of applications. This review provides an overview of the most recent works related to the use of click chemistry methodology in the field of nucleosides, nucleotides and nucleic acids for pharmacological applications.

A Synthesis of 2-Amino-2,6-dideoxy-D-(and L-)galaetose (Fucosamine) and 2-Amino-2,6-dideoxy-D-(and L-)talose (Pneumosamine)

1973 ◽  
Vol 51 (6) ◽  
pp. 974-977 ◽  
Author(s):  
Malcolm B. Perry ◽  
Virginia Daoust
Keyword(s):  
Similar Reaction ◽  
Reaction Sequence ◽  
Reaction Conditions ◽  
Nef Reaction ◽  
Methanolic Ammonia

5-Deoxy-D-lyxose underwent base-catalyzed addition with nitromethane to give a mixture of 1,6-dideoxy-1-nitro-D-galactitol and 1,6-dideoxy-1-nitro-D-talitol (ca. 2:1). Acetylation of the crystalline 1,6-dideoxy-1-nitro-D-galactitol gave 2,3,4,5-tetra-O-acetyl-1,6-dideoxy-1-nitro-D-galactitol which on treatment with methanolic ammonia afforded 2-acetamido-1,2,6-trideoxy-1-nitro-D-talitol and 2-acetamido-1,2,6-trideoxy-1-nitro-D-galactitol (ca. 3:1) which under the modified Nef reaction conditions gave 2-acetamido-2,6-dideoxy-D-talose and 2-acetamido-2,6-dideoxy-D-galactose respectively. The glycoses were converted to 2-amino-2,6-dideoxy-D-talose hydrochloride and 2-amino-2,6-dideoxy-D-galactose hydrochloride on hydrolysis with hydrochloric acid.A similar reaction sequence applied to 5-deoxy-L-lyxose afforded the L-enantiomorphic intermediates, and gave 2-amino-2,6-dideoxy-L-talose hydrochloride and 2-amino-2,6-dideoxy-L-galactose hydrochloride as final products.

scholarly journals Synthesis and Antibacterial Activity of New Spiro[thiadiazoline-(pyrazolo[3,4-d]pyrimidine)] Derivatives

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Mohammed El Fal ◽  
Youssef Ramli ◽  
Abdelfettah Zerzouf ◽  
Ahmed Talbaoui ◽  
Youssef Bakri ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Spectroscopic Data ◽  
Heterocyclic Compounds ◽  
Dipolar Cycloaddition ◽  
Bacterial Strains ◽  
Pyrimidine Derivatives ◽  
H Nmr ◽  
Biological Interest ◽  
Mic Value

New heterocyclic compounds spiroderivatives of allopurinol of biological interest were prepared from allopurinol via thionation and 1,3-dipolar cycloaddition and were produced in high to excellent yields. These compounds were characterized on the basis of spectral and spectroscopic data (1H NMR,13C, IR, and MS). The antibacterial activity of the synthesized products was studied using bacterial strains:Staphylococcus aureus,Enterococcus faecalis,Escherichia coli, andPseudomonas aeruginosa. Compounds having an ethyl group showed the best activity with MIC value of 31.25 µg/mL againstStaphylococcus aureusandStreptococcus fasciens.

ChemInform Abstract: Unexpected 1,3-Dipolar Cycloaddition Reaction of Thiazolo[3,2-a]pyrimidine Derivatives and Nitrilimine.

ChemInform ◽  
2011 ◽  
Vol 42 (35) ◽  
pp. no-no
Author(s):  
Xiaofang Li ◽  
Haochong Liu ◽  
Bin Liu ◽  
Aiting Zheng ◽  
Guobin Li ◽  
...  
Keyword(s):  
Cycloaddition Reaction ◽  
Dipolar Cycloaddition ◽  
Pyrimidine Derivatives

scholarly journals Appel-reagent-mediated transformation of glycosyl hemiacetal derivatives into thioglycosides and glycosyl thiols

2013 ◽  
Vol 9 ◽  
pp. 974-982 ◽  
Author(s):  
Tamashree Ghosh ◽  
Abhishek Santra ◽  
Anup Kumar Misra
Keyword(s):  
Reaction Sequence ◽  
Reaction Conditions ◽  
One Pot ◽  
Carbon Tetrabromide

A series of glycosyl hemiacetal derivatives have been transformed into thioglycosides and glycosyl thiols in a one-pot two-step reaction sequence mediated by Appel reagent (carbon tetrabromide and triphenylphosphine). 1,2-trans-Thioglycosides and β-glycosyl thiol derivatives were stereoselectively formed by the reaction of the in situ generated glycosyl bromides with thiols and sodium carbonotrithioate. The reaction conditions are reasonably simple and yields were very good.

Probing the Reactivity of 2,4-Dichlorofuro[3,4-d]pyrimidin-7-one: A Versatile and Underexploited Scaffold to Generate Substituted or Fused Pyrimidine Derivatives

Synlett ◽  
2019 ◽  
Vol 30 (17) ◽  
pp. 2010-2014
Author(s):  
Paolo Vincetti ◽  
Gabriele Costantino ◽  
Maria Grazia Martina ◽  
Marco Radi
Keyword(s):  
Chemical Reactivity ◽  
Pyrimidine Derivatives ◽  
Reaction Conditions ◽  
One Pot ◽  
Microwave Assisted ◽  
Set Up

Herein, we describe the results of our investigation on the chemical reactivity and versatility of a poorly explored scaffold: 2,4-dichlorofuro[3,4-d]pyrimidin-7-one (3). Highly functionalized pyrimidines can be obtained with a divergent approach by reacting the key intermediate 3 with different amine nucleophiles under carefully controlled reaction conditions. The set-up of a microwave-assisted one-pot, two- or three-step protocol to rapidly generate 2,4,5,6-tetrasubstituted or fused pyrimidines is also reported.

Photoinduced, strain-promoted cycloadditions of trans-cycloheptenones and azides

2020 ◽  
Vol 22 (20) ◽  
pp. 7023-7030
Author(s):  
Hongzhi Yang ◽  
Tianying Zeng ◽  
Shuang Xi ◽  
Shengkun Hu ◽  
Yunfei Wu ◽  
...  
Keyword(s):  
Oxidation Reaction ◽  
Aerobic Oxidation ◽  
Dipolar Cycloaddition ◽  
Reaction Sequence ◽  
Metal Free

Metal-free cycloadditions of cycloheptenones with azides have been developed, hinging on a photoisomerization/1,3-dipolar cycloaddition/aerobic oxidation reaction sequence.

scholarly journals Enantioselective 1,3-Dipolar Cycloaddition Reaction of Nitrones with α-(Acyloxy)acroleins Catalyzed by Dipeptide-Derived Chiral Tri- or Diammonium Salts

Synlett ◽  
2019 ◽  
Vol 30 (15) ◽  
pp. 1835-1839 ◽  
Author(s):  
Chihiro Kidou ◽  
Haruki Mizoguchi ◽  
Tatsuo Nehira ◽  
Akira Sakakura
Keyword(s):  
Cycloaddition Reaction ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Reaction Conditions

Organoammonium salts of dipeptide-derived chiral triamines or diamines with TfOH catalyzed the enantioselective 1,3-dipolar cycloaddition reactions of α-acyloxyacroleins with nitrones to give the corresponding adducts in good yields (up to 96%) and with high diastereo- and enantioselectivities (up to 89% ee). Although α-(p-methoxybenzoyloxy)acrolein is rather unstable under the reaction conditions, α-(3-pyrroline-1-carbonyloxy)acrolein is stable enough to be smoothly converted into the corresponding adducts with the aid of the chiral organoammonium salt catalysts.

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