An operationally simple sonogashira reaction for an undergraduate organic chemistry laboratory class

Cranwell, P. ORCID: https://orcid.org/0000-0001-7156-5576, Peterson, A.M., Littlefield, B. and Russell, A. (2015) An operationally simple sonogashira reaction for an undergraduate organic chemistry laboratory class. Journal of Chemical Education. ISSN 0021-9584 doi: 10.1021/acs.jchemed.5b00030

Abstract/Summary

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.