Intramolecular cyclization–decyclization of new sterically hindered diiminophenol. Synthesis and coordination abilities

RSC Advances ◽  
2014 ◽  
Vol 4 (28) ◽  
pp. 14495-14500 ◽  
Author(s):  
Gleb A. Abakumov ◽  
Nikolay O. Druzhkov ◽  
Elena N. Egorova ◽  
Tatiana N. Kocherova ◽  
Andrey S. Shavyrin ◽  
...  
Keyword(s):  
Intramolecular Cyclization ◽  
The Novel ◽  
Cadmium Complexes ◽  
Coordination Type ◽  
Sterically Hindered

The novel benzoxazole I undergoes a fast intramolecular decyclization and demonstrates either a neutral or anionic coordination type in cadmium complexes.

Nucleophilic Substitution Reactions of Tetrabutylammonium aci-Nitronates with p-Substituted Nitrobenzenes

1979 ◽  
Vol 32 (11) ◽  
pp. 2413 ◽  
Author(s):  
RK Norris ◽  
D Randles
Keyword(s):  
Dimethyl Sulfoxide ◽  
Nucleophilic Substitution ◽  
Lithium Salts ◽  
Methyl Groups ◽  
The Novel ◽  
Substitution Reactions ◽  
Nucleophilic Substitution Reactions ◽  
Sterically Hindered

The reactions of tetrabutylammonium aci-nitronates with p-dinitrobenzene in dimethyl sulfoxide, benzene or acetone proceed far more rapidly than the reactions of the corresponding lithium salts and give, in unhindered cases, good yields of C-arylates, e.g. p-(1-methyl-1-nitroethyl)nitrobenzene (in 73-89% yields) and p-nitro(l,3,3-trimethyl-1-nitrobuty1)benene (in 70% yield). With more sterically hindered nitronates, O-arylation increases, giving phenols and ketoxime O-p-nitrophenyl ethers, presumably derived from the novel, intermediate p-nitrophenyl aci-nitronate esters. aci-Nitronate ions with more than two β-methyl groups gave no C-arylation. Similar results were obtained with p-fluoronitrobenzene and p-nitrobenzonitrile, A mechanism for the conversion of the intermediate aci-nitronate esters into the ketoxime ethers is proposed.

scholarly journals Annulation of a 1,3-dithiole ring to a sterically hindered o-quinone core. Novel ditopic redox-active ligands

2021 ◽  
Vol 17 ◽  
pp. 273-282 ◽  
Author(s):  
Sergey V Norkov ◽  
Anton V Cherkasov ◽  
Andrey S Shavyrin ◽  
Maxim V Arsenyev ◽  
Viacheslav A Kuropatov ◽  
...  
Keyword(s):  
Metal Ions ◽  
Spin Density ◽  
Functional Groups ◽  
Quinone Methide ◽  
Redox Activity ◽  
The Novel ◽  
Redox Active Ligands ◽  
Redox Active ◽  
Sterically Hindered ◽  
Quinone Derivative

The fused 1,3-dithiole spacer seems to be very suitable for the functionalization of sterically hindered o-quinones with additional groups capable of coordination of metal ions and/or possessing a redox activity. An effective method for the synthesis of sterically hindered o-quinones containing 1,3-diketonate, dinitrile and p-quinone-methide functional groups at the periphery of the ligand has been developed. The novel compounds have rigid and conjugated structures and exhibit properties typical of o-quinones. A study of their monoreduced semiquinone derivatives reveal that the spin density is delocalized across the whole molecule, including peripheral fragments. The first stable o-quinone derivative bearing an annulated thiete heterocycle has been isolated and characterized.

Total Synthesis of ( ± )-α-Cubebene and ( ± )-β-Cubebene

1971 ◽  
Vol 49 (1) ◽  
pp. 12-19 ◽  
Author(s):  
Edward Piers ◽  
Ronald W. Britton ◽  
William De Waal
Keyword(s):  
Total Synthesis ◽  
Intramolecular Cyclization ◽  
High Yield ◽  
Cupric Sulfate ◽  
The Novel

An efficient total synthesis of the racemic forms of the novel tricyclic sesquiterpenes α-cubebene (1) and β-cubebene (2) is described. The key step of this synthesis involved the cupric sulfate catalyzed intramolecular cyclization of the olefinic diazoketone 3, which produced, in high yield, ( ± )-β-cubebene norketone (24) and ( ± )-1,6-epi-β-cubebene norketone (25), in a ratio of approximately 3:5, respectively.

scholarly journals In vitro circumvention of cisplatin resistance by the novel sterically hindered platinum complex AMD473

1998 ◽  
Vol 77 (3) ◽  
pp. 366-373 ◽  
Author(s):  
J Holford ◽  
SY Sharp ◽  
BA Murrer ◽  
M Abrams ◽  
LR Kelland
Keyword(s):  
Cisplatin Resistance ◽  
Platinum Complex ◽  
The Novel ◽  
Sterically Hindered

New functionalized sterically hindered o-aminophenols: Reversible intramolecular cyclization

2013 ◽  
Vol 448 (2) ◽  
pp. 44-48
Author(s):  
V. K. Cherkasov ◽  
N. O. Druzhkov ◽  
T. N. Kocherova ◽  
E. N. Egorova ◽  
A. S. Shavyrin
Keyword(s):  
Intramolecular Cyclization ◽  
Sterically Hindered

An unexpected formation of the novel 7-oxa-2-azabicyclo[2.2.1]hept-5-ene skeleton during the reaction of furfurylamine with maleimides and their bioprospection using a zebrafish embryo model

2013 ◽  
Vol 11 (3) ◽  
pp. 407-411 ◽  
Author(s):  
Carlos E. Puerto Galvis ◽  
Vladimir V. Kouznetsov
Keyword(s):  
Green Synthesis ◽  
Intramolecular Cyclization ◽  
Zebrafish Embryo ◽  
The Novel ◽  
Unexpected Formation ◽  
Novel Strategy

An unexpected intramolecular cyclization during the reaction of furfurylamine with maleimides is reported as a novel strategy for the efficient green synthesis of the 7-oxa-2-azabicyclo[2.2.1]hept-5-ene skeleton.

Synthesis of new condensed and cyclized coumarin derivatives

2007 ◽  
Vol 61 (3) ◽  
Author(s):  
S. Dekić ◽  
V. Dekić ◽  
B. Dekić ◽  
M. Dekić
Keyword(s):  
Acid Hydrolysis ◽  
Intramolecular Cyclization ◽  
13C Nmr ◽  
Catalytic Amount ◽  
The Novel ◽  
Coumarin Derivatives ◽  
1H And 13C Nmr

AbstractCondensation of 4-chloro-2-oxo-2H-chromene-3-carbonitrile with selected heteroarylamines in acetonitrile containing a catalytic amount of triethylamine, followed by intramolecular cyclization, gave the new coumarin derivatives with yields ranging from 43 % to 78 %. The novel compounds were subjected to acid hydrolysis giving the corresponding oxo derivatives in 66–70 % yield. The structural assignments of the synthesized compounds were based on elemental, IR, 1H and 13C NMR analyses.

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