ChemInform Abstract: Phosphane-Catalyzed [3 + 3] Annulation of C,N-Cyclic Azomethine Imines with Ynones: A Practical Method for Tricyclic Dinitrogen-Fused Heterocycles.

ChemInform ◽  
2016 ◽  
Vol 47 (43) ◽  
Author(s):  
Zhen Li ◽  
Hao Yu ◽  
Yang Liu ◽  
Leijie Zhou ◽  
Zhanhu Sun ◽  
...  
Keyword(s):  
Practical Method ◽  
Fused Heterocycles ◽  
Azomethine Imines

Phosphane-Catalyzed [3+3] Annulation of C,N-Cyclic Azomethine Imines with Ynones: A Practical Method for Tricyclic Dinitrogen-Fused Heterocycles

2016 ◽  
Vol 358 (12) ◽  
pp. 1880-1885 ◽  
Author(s):  
Zhen Li ◽  
Hao Yu ◽  
Yang Liu ◽  
Leijie Zhou ◽  
Zhanhu Sun ◽  
...  
Keyword(s):  
Practical Method ◽  
Fused Heterocycles ◽  
Azomethine Imines

Further Synthetic Applications of Functionalized 1,3-Dipoles

1975 ◽  
Vol 53 (24) ◽  
pp. 3782-3790 ◽  
Author(s):  
J. William Lown ◽  
B. Erik Landberg
Keyword(s):  
Ring Closure ◽  
Ethyl Diazoacetate ◽  
Fused Heterocycles ◽  
Leaving Group ◽  
Nitrile Imines ◽  
Azomethine Imines

Reactions of nitrile imines, azomethine imines, and ethyl diazoacetate (as representatives of functionalized 1,3-dipoles) with reactive olefins lead to a series of novel fused heterocycles after suitable ring closure. The influence of the nature of the heterocyclic leaving group and the substituents in the phenacyl residue in a group of phenacylimidazolium salts on the course of their reaction to produce 1,2-dihydrofurans and perhydropyrazolopyrroles is investigated.

CuI-Catalyzed [3+2] Cycloaddition of Hindered Vinylidenebisphosphonates (VBP) with Azomethine Imines for Highly Regioselective Access to Dinitrogen-Heterobicycle-Containing Bisphosphonates

Synthesis ◽  
2018 ◽  
Vol 50 (13) ◽  
pp. 2601-2607
Author(s):  
Zhongxiang Zhu ◽  
Qinghe Wang ◽  
Dulin Kong ◽  
Tiao Huang ◽  
Mingshu Wu
Keyword(s):  
Biological Activity ◽  
Low Cost ◽  
Cycloaddition Reaction ◽  
Dipolar Cycloaddition ◽  
Atom Economy ◽  
Mild Conditions ◽  
Synthetic Strategy ◽  
Fused Heterocycles ◽  
Azomethine Imines ◽  
High Stereoselectivity

A concise, atom-economic, and highly regioselective synthetic strategy for the construction of several dinitrogen-fused heterocycles bearing bisphosphonates by 1,3-dipolar cycloaddition reaction of azomethine imines with tetraethyl vinylidene-1,1-bisphosphonate in the presence of CuI in toluene media has been developed. The targeted compounds were obtained in good yields and with excellent regioselectivity. This method for the synthesis of gem-bisphosphonates (BPs) is particularly attractive due to features such as low cost, mild conditions, atom economy, high stereoselectivity, and potential biological activity of the product.

Thermal [3+2] cycloaddition reaction of azomethine imines with allenoates for dinitrogen-fused heterocycles

Tetrahedron ◽  
2012 ◽  
Vol 68 (10) ◽  
pp. 2349-2356 ◽  
Author(s):  
Risong Na ◽  
Honglei Liu ◽  
Zhen Li ◽  
Bo Wang ◽  
Jun Liu ◽  
...  
Keyword(s):  
Cycloaddition Reaction ◽  
Fused Heterocycles ◽  
Azomethine Imines

DABCO-catalyzed [3+2] cycloaddition reactions of azomethine imines with N -aryl maleimides: facile access to dinitrogen-fused heterocycles

2015 ◽  
Vol 56 (52) ◽  
pp. 7150-7153 ◽  
Author(s):  
Qianfa Jia ◽  
Lei Chen ◽  
Gongming Yang ◽  
Jian Wang ◽  
Jia Wei ◽  
...  
Keyword(s):  
Cycloaddition Reactions ◽  
Fused Heterocycles ◽  
Azomethine Imines

ChemInform Abstract: Thermal [3 + 2] Cycloaddition Reaction of Azomethine Imines with Allenoates for Dinitrogen-Fused Heterocycles.

ChemInform ◽  
2012 ◽  
Vol 43 (30) ◽  
pp. no-no
Author(s):  
Risong Na ◽  
Honglei Liu ◽  
Zhen Li ◽  
Bo Wang ◽  
Jun Liu ◽  
...  
Keyword(s):  
Cycloaddition Reaction ◽  
Fused Heterocycles ◽  
Azomethine Imines

The role of differential phase contrast in electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 176-177
Author(s):  
E.M. Waddell ◽  
J.N. Chapman ◽  
R.P. Ferrier
Keyword(s):  
Phase Contrast ◽  
Practical Method ◽  
Position Vector ◽  
Differential Phase ◽  
Pure Phase ◽  
Differential Phase Contrast ◽  
The Difference ◽  
Image Position ◽  
First Moment

Dekkers and de Lang (1977) have discussed a practical method of realising differential phase contrast in a STEM. The method involves taking the difference signal from two semi-circular detectors placed symmetrically about the optic axis and subtending the same angle (2α) at the specimen as that of the cone of illumination. Such a system, or an obvious generalisation of it, namely a quadrant detector, has the characteristic of responding to the gradient of the phase of the specimen transmittance. In this paper we shall compare the performance of this type of system with that of a first moment detector (Waddell et al.1977).For a first moment detector the response function R(k) is of the form R(k) = ck where c is a constant, k is a position vector in the detector plane and the vector nature of R(k)indicates that two signals are produced. This type of system would produce an image signal given bywhere the specimen transmittance is given by a (r) exp (iϕ (r), r is a position vector in object space, ro the position of the probe, ⊛ represents a convolution integral and it has been assumed that we have a coherent probe, with a complex disturbance of the form b(r-ro) exp (iζ (r-ro)). Thus the image signal for a pure phase object imaged in a STEM using a first moment detector is b2 ⊛ ▽ø. Note that this puts no restrictions on the magnitude of the variation of the phase function, but does assume an infinite detector.

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