Reductive Cyclization of Amino α-Keto Esters. A General Method for the Synthesis of Nitrogen-Heterocyclics Having Fused Five- and Six-Membered Rings

1950 ◽  
Vol 72 (7) ◽  
pp. 2980-2985 ◽  
Author(s):  
Nelson J. Leonard ◽  
Joseph H. Boyer
Keyword(s):  
Reductive Cyclization ◽  
Keto Esters ◽  
General Method

Formation of quaternary centres via iron allyl cations. Rapid entry into spirocyclic ring systems

1997 ◽  
Vol 75 (7) ◽  
pp. 965-974 ◽  
Author(s):  
M. Anne Charlton ◽  
James R. Green
Keyword(s):  
Reductive Cyclization ◽  
Cyclization Reactions ◽  
Dicarbonyl Compounds ◽  
Enol Ethers ◽  
Ring Systems ◽  
Silyl Enol Ethers ◽  
Keto Esters ◽  
Condensation Products ◽  
Ketene Acetals ◽  
Silyl Ketene Acetals

Ester-substituted allyltetracarbonyliron cations react with cycloalkylidene-type silyl enol ethers, silyl ketene acetals, and β-keto-esters to give 1,6-dicarbonyl compounds containing a newly formed quaternary centre. Selected condensation products are converted by enolate chemistry into spirocyclic [4.4], [4.5], and [4.6] systems. Acyloin and other reductive cyclization reactions are employed to convert the condensation products into spirocyclic [4.5], [5.5], and [5.6] systems. Keywords: allyliron complexes, umpolung synthesis, 1,6-dicarbonyls, spirocycle synthesis.

A General Method for the Enantioselective Hydrogenation of β-Keto Esters using Monodentate Binaphthophosphepine Ligands

2005 ◽  
Vol 347 (15) ◽  
pp. 1978-1986 ◽  
Author(s):  
Bernhard Hagemann ◽  
Kathrin Junge ◽  
Stephan Enthaler ◽  
Manfred Michalik ◽  
Thomas Riermeier ◽  
...  
Keyword(s):  
Enantioselective Hydrogenation ◽  
Keto Esters ◽  
General Method

A General Method for Spectrometer Design in the Scoff Approximation

1976 ◽  
Vol 34 ◽  
pp. 538-539
Author(s):  
J. R. Fields
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Energy Analysis ◽  
Incident Beam ◽  
Scanning Transmission Electron Microscope ◽  
Chemical Identification ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
General Method

The energy analysis of electrons scattered by a specimen in a scanning transmission electron microscope can improve contrast as well as aid in chemical identification. In so far as energy analysis is useful, one would like to be able to design a spectrometer which is tailored to his particular needs. In our own case, we require a spectrometer which will accept a parallel incident beam and which will focus the electrons in both the median and perpendicular planes. In addition, since we intend to follow the spectrometer by a detector array rather than a single energy selecting slit, we need as great a dispersion as possible. Therefore, we would like to follow our spectrometer by a magnifying lens. Consequently, the line along which electrons of varying energy are dispersed must be normal to the direction of the central ray at the spectrometer exit.

Phase behavior of cationic and anionic surfactants at low concentrations

1992 ◽  
Vol 50 (1) ◽  
pp. 694-695
Author(s):  
E. Naranjo
Keyword(s):  
Phase Behavior ◽  
Structural Characterization ◽  
Dynamic Systems ◽  
Anionic Surfactants ◽  
Intermolecular Forces ◽  
Stable Form ◽  
Surfactant Mixtures ◽  
Low Concentrations ◽  
Cationic And Anionic Surfactants ◽  
General Method

Equilibrium vesicles, those which are the stable form of aggregation and form spontaneously on mixing surfactant with water, have never been demonstrated in single component bilayers and only rarely in lipid or surfactant mixtures. Designing a simple and general method for producing spontaneous and stable vesicles depends on a better understanding of the thermodynamics of aggregation, the interplay of intermolecular forces in surfactants, and an efficient way of doing structural characterization in dynamic systems.

Caricaturing as a general method to improve poor face recognition: Evidence from low-resolution images, other-race faces, and older adults.

2019 ◽  
Vol 25 (2) ◽  
pp. 256-279 ◽  
Author(s):  
Amy Dawel ◽  
Tsz Ying Wong ◽  
Jodie McMorrow ◽  
Callin Ivanovici ◽  
Xuming He ◽  
...  
Keyword(s):  
Older Adults ◽  
Face Recognition ◽  
Low Resolution ◽  
General Method ◽  
Low Resolution Images
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