47 research outputs found
Trends in the incidence of venous stasis syndrome and venous ulcer: A 25-year population-based study
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An operationally simple sonogashira reaction for an undergraduate organic chemistry laboratory class
An operationally simple, reliable, and cheap Sonogashira
reaction suitable for an undergraduate laboratory class that can be completed within a day-long (8 h) laboratory session has been developed. Cross-coupling is carried out between 2-methyl-3-butyn-2-ol and various aryl iodides using catalytic amounts of bis-(triphenylphosphine)palladium(II) dichloride, with copper(I) iodide as a cocatalyst, in triethylamine at room temperature, so a range of products can be prepared within a single group and results compared. The coupling itself is usually complete within 1.5 h and is easily
monitored by TLC, leaving up to 6 h for purification and
characterization. Purification is by “mini flash column chromatography” through a plug of silica encased in the barrel of a plastic syringe, so the procedure is amenable to large class sizes