One-Step Preparation of N-Unprotected Aziridines from 2H-Azirines by Addition of Ketene Silyl Acetals Catalyzed by Lewis Acids

2021 ◽  
Author(s):  
Itaru Suzuki ◽  
Yuya Takenaka ◽  
Yoshitaka Morishita ◽  
Ikuya Shibata
Keyword(s):  
Lewis Acids ◽  
One Step ◽  
Silyl Acetals

Glycosyloxymethylfurfural (GMF) in Multicomponent Aza-Morita-Baylis-Hillman Reaction: Rapid Access to Highly Functionalized Carbohydrate Scaffolds

2018 ◽  
Vol 15 (3) ◽  
pp. 430-435 ◽  
Author(s):  
Jia-Neng Tan ◽  
Mohammed Ahmar ◽  
Yves Queneau
Keyword(s):  
Lewis Acids ◽  
Reaction Conditions ◽  
Dehydration Product ◽  
Carbonyl Derivatives ◽  
Michael Acceptor ◽  
One Step ◽  
The One ◽  
New Compounds ◽  
Optimized Conditions ◽  
Mbh Reaction

Aim and Objective: The use of glycosyloxymethylfurfural (GMF), the dehydration product of isomaltulose, in the one-step multicomponent aza-Morita-Baylis-Hillman (aza-MBH) reaction, was studied. Materials and Methods: The reaction conditions and scope were investigated with respect to solvent, combinations of catalysts (Lewis acids and nucleophilic base), and the nature of the amine and the acrylic partners. Results: The three-components one step aza-MBH reaction using GMF, sulfonamides and a Michael acceptor provides carbohydrate-based a-methylene-b-amino carbonyl derivatives in moderate to good yields. Optimized conditions are the use of La(OTf)3 and 3-HQD in methanol. The use of diphenylphosphinamide, though requiring the use of a protected GMF and a two-step protocol, offers alternatives in the type of activated imine involved the classical sulfonyl substitution. Conclusion: A wide structural range of adducts were obtained in fair to good yields, showing the synthetic efficiency of the strategy able to provide highly functionalized carbohydrate-containing new molecules in an unique step from very available starting materials. These explorations show that GMF can be transformed in very short sequences to rather elaborated new compounds using the MBH and aza-MBH strategy.

Alkylation of Ketene Silyl Acetals with Nitroolefins Mediated by Sterically Encumbered Lewis Acids

1997 ◽  
Vol 62 (13) ◽  
pp. 4370-4375 ◽  
Author(s):  
John A. Tucker ◽  
Terrance L. Clayton ◽  
Donald M. Mordas
Keyword(s):  
Lewis Acids ◽  
Silyl Acetals

ChemInform Abstract: Alkylation of Ketene Silyl Acetals with Nitroolefins Mediated by Sterically Encumbered Lewis Acids.

ChemInform ◽  
2010 ◽  
Vol 28 (48) ◽  
pp. no-no
Author(s):  
J. A. TUCKER ◽  
T. L. CLAYTON ◽  
D. M. MORDAS
Keyword(s):  
Lewis Acids ◽  
Silyl Acetals

An Interactive Minicomputer Program for the Indexing and Simulation of Electron Diffraction Patterns

1976 ◽  
Vol 34 ◽  
pp. 542-543
Author(s):  
R.P. Goehner ◽  
W.T. Hatfield ◽  
Prakash Rao
Keyword(s):  
Electron Diffraction ◽  
Real Time ◽  
Pattern Analysis ◽  
Flow Diagram ◽  
Hard Copy ◽  
Time Analysis ◽  
Real Time Analysis ◽  
Transmission Electron ◽  
One Step ◽  
Diffraction Patterns

Computer programs are now available in various laboratories for the indexing and simulation of transmission electron diffraction patterns. Although these programs address themselves to the solution of various aspects of the indexing and simulation process, the ultimate goal is to perform real time diffraction pattern analysis directly off of the imaging screen of the transmission electron microscope. The program to be described in this paper represents one step prior to real time analysis. It involves the combination of two programs, described in an earlier paper(l), into a single program for use on an interactive basis with a minicomputer. In our case, the minicomputer is an INTERDATA 70 equipped with a Tektronix 4010-1 graphical display terminal and hard copy unit.A simplified flow diagram of the combined program, written in Fortran IV, is shown in Figure 1. It consists of two programs INDEX and TEDP which index and simulate electron diffraction patterns respectively. The user has the option of choosing either the indexing or simulating aspects of the combined program.

Nutrient-regulated gene expression in eukaryotes

2006 ◽  
Vol 73 ◽  
pp. 85-96 ◽  
Author(s):  
Richard J. Reece ◽  
Laila Beynon ◽  
Stacey Holden ◽  
Amanda D. Hughes ◽  
Karine Rébora ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcriptional Control ◽  
Direct Interaction ◽  
Signalling Pathways ◽  
A Cell ◽  
One Step ◽  
Higher Eukaryotes ◽  
Regulated Gene Expression

The recognition of changes in environmental conditions, and the ability to adapt to these changes, is essential for the viability of cells. There are numerous well characterized systems by which the presence or absence of an individual metabolite may be recognized by a cell. However, the recognition of a metabolite is just one step in a process that often results in changes in the expression of whole sets of genes required to respond to that metabolite. In higher eukaryotes, the signalling pathway between metabolite recognition and transcriptional control can be complex. Recent evidence from the relatively simple eukaryote yeast suggests that complex signalling pathways may be circumvented through the direct interaction between individual metabolites and regulators of RNA polymerase II-mediated transcription. Biochemical and structural analyses are beginning to unravel these elegant genetic control elements.

CAD: One Step Forward, One Step Back

2010 ◽  
Vol 43 (18) ◽  
pp. 16
Author(s):  
MATTHEW R.G. TAYLOR
Keyword(s):  
One Step

One-Step Synthesis and Magnetic Phase Transformation of Ln-TM-B Alloy by Chemical Reduction

2007 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
C.W. Kim ◽  
Y.H. Kim ◽  
H.G. Cha ◽  
D.K. Lee ◽  
Y.S. Kang
Keyword(s):  
Phase Transformation ◽  
Magnetic Phase ◽  
Chemical Reduction ◽  
One Step
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