Reaction of CO and tert-butyl isocyanide with the cluster [(C5Me5)3Co3(µ2-H)3(µ3-H)] facile hydrogen transfer to isocyanide forms [(C5Me5)3Co3(µ-H)(µ3-η2-HCNCMe3)]

1993 ◽  
pp. 1692-1694 ◽  
Author(s):  
Charles P. Casey ◽  
Ross A. Widenhoefer ◽  
Susan L. Hallenbeck ◽  
James A. Gavney
Keyword(s):  
Hydrogen Transfer ◽  
Tert Butyl

The long and winding road to new porphycenes

2012 ◽  
Vol 16 (05n06) ◽  
pp. 589-602 ◽  
Author(s):  
Igor Czerski ◽  
Arkadiusz Listkowski ◽  
Jan Nawrocki ◽  
Natalia Urbańska ◽  
Hubert Piwoński ◽  
...  
Keyword(s):  
Fluorescence Polarization ◽  
Hydrogen Transfer ◽  
Single Molecules ◽  
Tert Butyl ◽  
Tautomeric Forms ◽  
By Products ◽  
Double Hydrogen

We describe attempts — not always successful — made over the years to improve the efficiency of porphycene synthesis and to produce novel compounds, custom-designed for specific purposes. New porphycenes are reported, some of them obtained rather unexpectedly as by-products of the planned reactions. Structure and energy computations of possible tautomeric forms in porphycenes substituted by one, two, three, and four tert-butyl groups lead to predictions regarding the kinetics and mechanisms of intramolecular double hydrogen transfer. The occurrence of tautomerization in single molecules of tert-butylsubstituted porphycenes is demonstrated by using fluorescence polarization techniques.

Asymmetric calixarene derivatives as potential hosts in chiral recognition processes

2015 ◽  
Vol 87 (4) ◽  
pp. 415-439 ◽  
Author(s):  
Catalin V. Maftei ◽  
Elena Fodor ◽  
Peter G. Jones ◽  
M. Heiko Franz ◽  
Corneliu M. Davidescu ◽  
...  
Keyword(s):  
Chiral Recognition ◽  
Hydrogen Transfer ◽  
Amide Bond ◽  
Transfer Reactions ◽  
Ester Bond ◽  
X Ray ◽  
Tert Butyl ◽  
Asymmetric Catalytic ◽  
Catalytic Hydrogen ◽  
Derivatives Of

AbstractNew chiral derivatives of 15,35,55,75-tetra-tert-butyl-1,3,5,7(1,3)-tetrabenzenacyclooctaphane-12,32,52,72-tetraol [(1); tert-butyl-calix[4]-arene] were synthesized by coupling modified chiral quinuclidines derived from the natural-product-based alkaloids quincorine and quincoridine with the calix[4]arene 1 via either an ester bond or an amide bond. X-ray analyses of two products were performed. Applications of the products in asymmetric catalytic hydrogen transfer reactions are described. A protocol is presented to multi-substitute calix[4]arene at the methylene bridges, resulting in, e.g., 2,6-carboxyl-all-tert-butyl all-methoxy-calix[4]arene.

Effect of Niacin on Mitochondria of Allium Cepa Root Cells

1967 ◽  
Vol 25 ◽  
pp. 78-79
Author(s):  
M. Arif Hayat
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Hydrogen Transfer ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Root Tips ◽  
Root Cells ◽  
Transfer Processes ◽  
Standard Procedures ◽  
A Cell ◽  
Critical Interest

Although it is recognized that niacin (pyridine-3-carboxylic acid), incorporated as the amide in nicotinamide adenine dinucleotide (NAD) or in nicotinamide adenine dinucleotide phosphate (NADP), is a cofactor in hydrogen transfer in numerous enzyme reactions in all organisms studied, virtually no information is available on the effect of this vitamin on a cell at the submicroscopic level. Since mitochondria act as sites for many hydrogen transfer processes, the possible response of mitochondria to niacin treatment is, therefore, of critical interest.Onion bulbs were placed on vials filled with double distilled water in the dark at 25°C. After two days the bulbs and newly developed root system were transferred to vials containing 0.1% niacin. Root tips were collected at ¼, ½, 1, 2, 4, and 8 hr. intervals after treatment. The tissues were fixed in glutaraldehyde-OsO4 as well as in 2% KMnO4 according to standard procedures. In both cases, the tissues were dehydrated in an acetone series and embedded in Reynolds' lead citrate for 3-10 minutes.

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