Darzens Reaction Rate Enhancement Using Aqueous Media Leading to a High Level of Kinetically Controlled Diastereoselective Synthesis of Steroidal Epoxyketones

2014 ◽  
Vol 79 (17) ◽  
pp. 8271-8277 ◽  
Author(s):  
Bo Li ◽  
Chunbao Li
Keyword(s):  
Reaction Rate ◽  
Aqueous Media ◽  
Diastereoselective Synthesis ◽  
Darzens Reaction ◽  
Rate Enhancement ◽  
Kinetically Controlled ◽  
High Level

Sintered Glasses for High-Level Wastes

1996 ◽  
Vol 465 ◽  
Author(s):  
D. O. Russo ◽  
N. B. Messi de Bernasconi ◽  
M. E. Sterba ◽  
A. D. Heredia ◽  
M. Sanfilippo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Aqueous Media ◽  
Underground Water ◽  
Aqueous Corrosion ◽  
Γ Radiation ◽  
Sintered Glass ◽  
A Value ◽  
Aqueous Corrosion Resistance ◽  
High Level

ABSTRACTThe objective of the work was to evaluate the long-term capacity of sintered glass to retain high-level nuclear wastes (HLW) in near-repository conditions. We have studied the corrosion behavior of waste forms partially devitrified (43 vol.%) in different aqueous media. Devitrified samples were irradiated at doses (γ radiation from a Co 60 source) ranging from 1.4 × 106 Gy to 2.0 × 108 Gy, in order to study their aqueous corrosion resistance in simulated underground water. The results show little or no effect of irradiation on the density, microstructure and corrosion resistance. The global dissolution rate was almost constant around a value of 5×10−5 g. cm−2 d−1. Elemental dissolution rates were also unaffected by radiation.

scholarly journals On the existence of and mechanism for microwave-specific reaction rate enhancement

2015 ◽  
Vol 6 (4) ◽  
pp. 2144-2152 ◽  
Author(s):  
Gregory B. Dudley ◽  
Ranko Richert ◽  
A. E. Stiegman
Keyword(s):  
Reaction Rate ◽  
Specific Reaction Rate ◽  
Specific Chemical ◽  
Rate Enhancement ◽  
Specific Reaction ◽  
Selective Heating ◽  
Dipolar Molecules ◽  
Chemical Rate

Microwave-specific chemical rate enhancement originates from the selective heating and accumulation of energy by solvated dipolar molecules in solution.

Rate enhancement of PFP sulfonate ester aminolysis by chloride salts in organic and aqueous media

2005 ◽  
Vol 46 (44) ◽  
pp. 7637-7640 ◽  
Author(s):  
Jonathan D. Wilden ◽  
Duncan B. Judd ◽  
Stephen Caddick
Keyword(s):  
Aqueous Media ◽  
Rate Enhancement ◽  
Sulfonate Ester ◽  
Ester Aminolysis ◽  
Chloride Salts

Comparison of betaine and l-stachydrine as phase-transfer catalysts in Michael addition and Darzens reaction

2006 ◽  
Vol 60 (5) ◽  
Author(s):  
E. Veverková ◽  
R. Droppová ◽  
Š. Toma
Keyword(s):  
Microwave Irradiation ◽  
Michael Addition ◽  
Reaction Rate ◽  
Catalytic Effect ◽  
Phase Transfer ◽  
Liquid System ◽  
Darzens Reaction ◽  
Phase Transfer Catalysts ◽  
Solid Liquid

AbstractBetaine and l-stachydrine have been tested as phase-transfer catalysts in Michael and Darzens reactions. The catalytic effect of l-stachydrine was found comparable to that of betaine in Michael addition and even higher when considering Darzens reaction. The desired products have been obtained in higher yields in solid-liquid system than under liquid-liquid bi-phase conditions. The influence of microwave irradiation and ultrasound on the reaction rate has been studied.

scholarly journals Reaction rate enhancement by surface diffusion of adsorbates

1992 ◽  
Vol 43 (2) ◽  
pp. 117-137 ◽  
Author(s):  
Dong Wang ◽  
Shi-Yuan Gou ◽  
Daniel Axelrod
Keyword(s):  
Surface Diffusion ◽  
Reaction Rate ◽  
Rate Enhancement
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