OXIDATION OF CIS- AND TRANS-1-AMINO-2,6-DIPHENYLPIPERIDINE. A NEW TYPE OF RING CLOSURE

1957 ◽  
Vol 79 (6) ◽  
pp. 1510-1511
Author(s):  
C. G. Overberger ◽  
Joseph G. Lombardino ◽  
Richard G. Hiskey
Keyword(s):  
Ring Closure ◽  
New Type ◽  
Cis And Trans

Stereochemical studies. Part 31. Ring closure reaction of cis- and trans-2-(bromomethyl)cycloalkylamines

1979 ◽  
pp. 1770-1773 ◽  
Author(s):  
György Göndös ◽  
Kornélia L. Láng ◽  
Andrea Szeghy ◽  
György Dombi ◽  
Gábor Bernáth
Keyword(s):  
Ring Closure ◽  
Cis And Trans

Theoretical Studies of the Physical Properties of Rodlike and Related Polymers

1988 ◽  
Vol 134 ◽  
Author(s):  
W. J. Welsh ◽  
J. E. Mark ◽  
Y. Yang ◽  
G. P. Das
Keyword(s):  
High Performance ◽  
Liquid Crystalline ◽  
Theoretical Work ◽  
Environmental Resistance ◽  
New Class ◽  
Protonated Forms ◽  
New Type ◽  
Electrooptical Properties ◽  
Cis And Trans ◽  
Strong Acids

ABSTRACTThis review focuses on a new type of para-catenated aromatic polymer being used in the preparation of high-performance films and fibers of exceptional strength, thermal stability, and environmental resistance, including inertness to essentially all common solvents. Polymers of this type include the cis- and trans-poly(p-phenylene benzobisoxazole) (PBO), the cis- and trans-forms of the corresponding poly(pphenylene benzobisthiazole) (PBT), and the structurally similar poly(5,5ʹ-bibenzoxazole-2.2ʹ-diyl-l,3-phenylene) (AAPBO) and poly(2,5-benzoxazole) (ABPBO) and their sulfurcontaining analogues. Because of their rigidity, these polymers become highly oriented in solution and some display liquid crystalline behavior. The purpose of this paper is to summarize the authorsʹ theoretical work on the structures, conformational energies, intermolecular interactions, electronic properties, electrical conductivity, and electrooptical properties of these chains, including, in some cases, the so-called articulated forms and the protonated forms known to exist in strong acids. The emphasis is on how such studies provide a molecular understanding of the unusual properties and processing characteristics of this new class of materials.

PYRAZOLINES: V. RING CLOSURE TO OXYGEN IN THE PYROLYSIS OF 3-ACETYL-Δ1-PYRAZOLINES

1965 ◽  
Vol 43 (5) ◽  
pp. 1398-1406 ◽  
Author(s):  
Donald E. McGreer ◽  
Norman W. K. Chiu ◽  
Magnus G. Vinje
Keyword(s):  
Ring Closure ◽  
Product Analysis ◽  
Pyrolysis Reaction ◽  
A Minor ◽  
Cis And Trans

The pyrolysis of 3-methyl-3-acetyl-Δ1-pyrazoline (IV) and cis- and trans-3,5-dimethyl-3-acetyl-Δ1-pyrazoline (V and VI) has been studied. Pyrolysis of IV gave 2,3-dimethyl-4,5-dihydrofuran (XI) as a minor product, indicating some ring closure to oxygen in these reactions. Pyrolysis of V gave 2,3,5-trimethyl-4,5-dihydrofuran (XVII) as 23% of the product, whereas VI yielded only a trace of XVII. This fact and other differences in the product analysis from isomers V and VI are discussed in terms of the possible mechanism for the pyrolysis reaction.

scholarly journals On a New Type of Rearrangement during Ring-closure.

1962 ◽  
Vol 16 ◽  
pp. 155-158 ◽  
Author(s):  
Salo Gronowitz ◽  
Pinchas Moses ◽  
Artturi I. Virtanen ◽  
K. Motzfeldt ◽  
Olof Theander ◽  
...  
Keyword(s):  
Ring Closure ◽  
New Type

ChemInform Abstract: RING CLOSURE REACTION OF CIS- AND TRANS-2-(BROMOMETHYL)CYCLOALKYLAMINES

1980 ◽  
Vol 11 (35) ◽  
Author(s):  
GY. GOENDOES ◽  
K. L. LANG ◽  
A. SZEGHY ◽  
GY. DOMBI ◽  
G. BERNATH
Keyword(s):  
Ring Closure ◽  
Cis And Trans

The Atetidine Ring-closure Reaction of cis- and trans-2-(Bromomethyl)cycloalkylamines

Heterocycles ◽  
1978 ◽  
Vol 9 (10) ◽  
pp. 1519
Author(s):  
Gy. Göndös ◽  
K. L. Láng ◽  
G. Bernáth
Keyword(s):  
Ring Closure ◽  
Cis And Trans

ChemInform Abstract: STEREOCHEMICAL STUDIES. PART 31. RING CLOSURE REACTION OF CIS- AND TRANS-2-(BROMOMETHYL)CYCLOALKYLAMINES

1979 ◽  
Vol 10 (43) ◽  
Author(s):  
G. GOENDOES ◽  
K. L. LANG ◽  
A. SZEGHY ◽  
G. DOMBI ◽  
G. BERNATH
Keyword(s):  
Ring Closure ◽  
Cis And Trans

scholarly journals Stereoselective Synthesis and Antiproliferative Activity of Steviol-Based Diterpen Aminodiols

2019 ◽  
Vol 21 (1) ◽  
pp. 184
Author(s):  
Dániel Ozsvár ◽  
Viktória Nagy ◽  
István Zupkó ◽  
Zsolt Szakonyi
Keyword(s):  
Antiproliferative Activity ◽  
Ring Opening ◽  
Stereoselective Synthesis ◽  
Click Reaction ◽  
Substituent Effects ◽  
Ring Closure ◽  
Secondary Amines ◽  
Structure Activity ◽  
Cis And Trans ◽  
Benzyl Substituent

A library of steviol-based trifunctional chiral ligands was developed from commercially available natural stevisoide and applied as chiral catalysts in the addition of diethylzinc to benzaldehyde. The key intermediate steviol methyl ester was prepared according to literature procedure. Depending on the epoxidation process, both cis- and trans-epoxyalcohols were obtained. Subsequent oxirane ring opening with primary and secondary amines afforded 3-amino-1,2-diols. The ring opening with sodium azide followed by a “click” reaction with alkynes resulted in dihydroxytriazoles. The regioselective ring closure of N-substituted aminodiols with formaldehyde was also investigated. The resulting steviol-type aminodiols were tested against a panel of human adherent cancer cell lines (A2780, SiHa, HeLa, and MDA-MB-231). It was consistently found that the N-benzyl substituent is an essential part within the molecule and the ring closure towards N-benzyl substituted oxazolidine ring system increased the antiproliferative activity to a level comparable with that of cisplatine. In addition, structure–activity relationships were examined by assessing substituent effects on the aminodiol systems.

Novel mixed-ligand Pt(II) complexes: Synthesis, multinuclear magnetic resonance, and crystal structures of cis- and trans-Pt(R2SO)(pyrazine)Cl2

2004 ◽  
Vol 82 (5) ◽  
pp. 649-658 ◽  
Author(s):  
Fernande D Rochon ◽  
Julien RL Priqueler
Keyword(s):  
Crystal Structure ◽  
Magnetic Resonance ◽  
Ir Spectroscopy ◽  
Crystal Structures ◽  
Mixed Ligand ◽  
The Other ◽  
Coupling Constant ◽  
New Type ◽  
Cis And Trans ◽  
Multinuclear Magnetic Resonance

A new type of mixed-ligand Pt(II) complexes, Pt(R2SO)(pyrazine)Cl2, was synthesized from the aqueous reaction of K[Pt(R2SO)Cl3] with pyrazine. The compounds were characterized mainly by IR and multinuclear magnetic resonance spectroscopies (1H, 13C, and 195Pt) and crystallography. Compounds with dimethylsulfoxide, tetramethylenesulfoxide, di-n-propylsulfoxide, di-n-butylsulfoxide, dibenzylsulfoxide, and diphenylsulfoxide were studied. IR spectroscopy suggested a cis geometry for the di-n-propylsulfoxide complex and trans geometry for the other compounds. The 195Pt NMR resonances of the complexes were observed between –3042 and –3121 ppm, with that of the diphenylsulfoxide complex being at higher field than those of the others. The pyrazine 3J(195Pt-1H) coupling constant was observed for the DMSO compound (33 Hz), suggesting a trans geometry. No J(195Pt-13C) coupling could be detected. The crystal structures of trans-Pt(tetramethylenesulfoxide)(pyrazine)Cl2 and of cis-Pt(di-n-propylsulfoxide)(pyrazine)Cl2 were determined and confirmed the geometry suggested by IR and NMR spectroscopies. The compound with di-n-butylsulfoxide could not be isolated, because it rapidly formed the pyrazine-bridged dimer. Key words: platinum, sulfoxide, pyrazine, crystal structure, NMR, IR.

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