Pd(OAc)2-Catalyzed Ligand-Free Suzuki Reaction in Ethylene Glycol at Room Temperature

Addition reactions of multi-functional amine, polyethylene imine (PEI) or diethylenetriamine (DETA), and poly(ethylene glycol) diglycidyl ether (PEGDE) or poly(ethylene glycol) diacrylate (PEGDA), have been investigated to obtain network polymers in H2O, dimethyl sulfoxide (DMSO), and ethanol (EtOH). Ring opening addition reaction of the multi-functional amine and PEGDE in H2O at room temperature or in DMSO at 90 °C using triphenylphosphine as a catalyst yielded gels. Aza-Michael addition reaction of the multi-functional amine and PEGDA in DMSO or EtOH at room temperature also yielded corresponding gels. Compression test of the gels obtained with PEI showed higher Young’s modulus than those with DETA. The reactions of the multi-functional amine and low molecular weight PEGDA in EtOH under the specific conditions yielded porous polymers induced by phase separation during the network formation. The morphology of the porous polymers could be controlled by the reaction conditions, especially monomer concentration and feed ratio of the multi-functional amine to PEGDA of the reaction system. The porous structure was formed by connected spheres or a co-continuous monolithic structure. The porous polymers were unbreakable by compression, and their Young’s modulus increased with the increase in the monomer concentration of the reaction systems. The porous polymers absorbed various solvents derived from high affinity between the polyethylene glycol units in the network structure and the solvents.

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ChemInform Abstract: A Highly Efficient Copper and Ligand Free Protocol for the Room Temperature Sonogashira Reaction.

ChemInform ◽

10.1002/chin.201521096 ◽

2015 ◽

Vol 46 (21) ◽

pp. no-no

Author(s):

Ankur Gogoi ◽

Anindita Dewan ◽

Utpal Bora

Keyword(s):

Room Temperature ◽

Sonogashira Reaction ◽

Highly Efficient ◽

Ligand Free

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The effects of osmotic pressure changes on the germination of Dictyostelium discoideum spores

Canadian Journal of Microbiology ◽

10.1139/m77-176 ◽

1977 ◽

Vol 23 (9) ◽

pp. 1170-1177 ◽

Cited By ~ 15

Author(s):

David A. Cotter

Keyword(s):

Ethylene Glycol ◽

Dictyostelium Discoideum ◽

Room Temperature ◽

Thermal Inactivation ◽

Sucrose Concentration ◽

Lag Phase ◽

Activation Process ◽

Sucrose Solutions ◽

Spore Population ◽

Pressure Changes

Polyalcohols such as ethylene glycol and glycerol at 3 M penetrate and activate spores of Dictyostelium discoideum incubated at room temperature. Higher concentrations of ethylene glycol result in lysis upon suspension of spores in dilute phosphate buffer. Erythritol and arabitol at 3 M do not penetrate or activate D. discoideum spores.Air-dried spores or those incubated in 2 M sucrose solutions are not activated with the usual heat treatment of 45 °C for 30 min. The plasmolyzed spores are activated at temperatures above 45 °C when heated in the presence of 2 M sucrose for 30 min. The temperature for maximum activation and the temperature for thermal inactivation of spores are raised 7–10 °C in high sucrose concentrations. Long-term incubation of heat-activated spores in 2 M sucrose solutions does not result in a return to dormancy.Moderate sucrose concentrations near 0.2 M do not block the heat-induced activation process but must be removed from the spore population to prevent a return to dormancy within 6 h. Other polyhydric compounds at 0.25 M concentration also cause spore deactivation within 6 h of room temperature incubation. Oxygen uptake of spores undergoing deactivation in 0.18 M sucrose is inhibited as compared to control levels. Moderate concentrations of sucrose do not block the early events of postactivation lag and the spores accumulate at the end of the lag phase. The longer the spores remain unswollen at the end of the postactivation lag phase, the greater the percentage of spores which return to dormancy. The effects of moderate sucrose concentration (lowered water activity) are not duplicated by the same quantity of Ficoll, indicating that the colligative properties of the sucrose solutions are responsible for deactivation.

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