ChemInform Abstract: A New Approach to the Efficient Indole Synthesis by Allene Intramolecular Cycloaddition.

1986 ◽  
Vol 17 (36) ◽  
Author(s):  
K. HAYAKAWA ◽  
T. YASUKOUCHI ◽  
K. KANEMATSU
Keyword(s):  
New Approach ◽  
Intramolecular Cycloaddition ◽  
Indole Synthesis

A new approach to the efficient indole synthesis by allene intramolecular cycloaddition

1986 ◽  
Vol 27 (16) ◽  
pp. 1837-1840 ◽  
Author(s):  
Kenji Hayakawa ◽  
Takanori Yasukouchi ◽  
Ken Kanematsu
Keyword(s):  
New Approach ◽  
Intramolecular Cycloaddition ◽  
Indole Synthesis

A Simple BF3•Et2O-mediated Cycloaddition Reaction to the Formation of Cyclic Monoterpenoid Pyrano[3,2-a]carbazole Alkaloids

2020 ◽  
Vol 17 ◽  
Author(s):  
Siow-Ping Tan ◽  
Mohd Azlan Nafiah
Keyword(s):  
Cytotoxic Activity ◽  
Cancer Cells ◽  
Lewis Acid ◽  
Cycloaddition Reaction ◽  
2D Nmr ◽  
Cytotoxic Effects ◽  
New Approach ◽  
Intramolecular Cycloaddition ◽  
Ic50 Values ◽  
Carbazole Alkaloids

Abstract: A Lewis acid BF3•Et2O-mediated intramolecular cycloaddition reaction of mahanimbine (1) is described. Three cycloadducts, bicyclomahanimbine (2), cyclomahanimbine (3) and murrayazolinine (4) were obtained. The structural char-acterization of these compounds were determined by 1D and 2D NMR experiments. These compounds showed no cytotoxic activity against human MRC-5 cells (IC50 > 60 μg/mL). Compound 3 showed the highest inhibition cytotoxic effects against HeLa and HL-60 cancer cells with IC50 values of 10.0 and 28.7 μg/mL, respectively. This strategy opens a new approach for the synthesis of biologically significant cyclic monoterpenoid pyrano[3,2-a]carbazole alkaloids

A new approach to polycyclic azaarenes: visible-light photolysis of vinyl azides in the synthesis of diazabenzopyrene and diazaperylene

2016 ◽  
Vol 4 (30) ◽  
pp. 7269-7276 ◽  
Author(s):  
J. A. Schneider ◽  
D. F. Perepichka
Keyword(s):  
Visible Light ◽  
Fluorescence Sensing ◽  
Dual Mode ◽  
New Approach ◽  
Sensing Properties ◽  
Vinyl Azides ◽  
Indole Synthesis

The Hemetsberger indole synthesis was repurposed for the preparation of luminescent electron-deficient azaarenes which display dual-mode pH fluorescence sensing properties.

The O–C diagrams of minor planets − a new approach to modelling the rotation

1999 ◽  
Vol 173 ◽  
pp. 185-188
Author(s):  
Gy. Szabó ◽  
K. Sárneczky ◽  
L.L. Kiss
Keyword(s):  
Error Analysis ◽  
Time Dependence ◽  
Theoretical Work ◽  
Minor Planet ◽  
Minor Planets ◽  
New Approach ◽  
Preliminary Results ◽  
Ccd Observations

AbstractA widely used tool in studying quasi-monoperiodic processes is the O–C diagram. This paper deals with the application of this diagram in minor planet studies. The main difference between our approach and the classical O–C diagram is that we transform the epoch (=time) dependence into the geocentric longitude domain. We outline a rotation modelling using this modified O–C and illustrate the abilities with detailed error analysis. The primary assumption, that the monotonity and the shape of this diagram is (almost) independent of the geometry of the asteroids is discussed and tested. The monotonity enables an unambiguous distinction between the prograde and retrograde rotation, thus the four-fold (or in some cases the two-fold) ambiguities can be avoided. This turned out to be the main advantage of the O–C examination. As an extension to the theoretical work, we present some preliminary results on 1727 Mette based on new CCD observations.

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