Tandem Sonogashira Coupling: An Efficient Tool for the Synthesis of Diarylalkynes, Zoltán Novák, Péter Nemes, András Kotschy, Org. Lett. 2005, 6, 4917-4920. DOI: 10.1021/ol047983f | [Full Text Link] [Supp. Info Link]
The tandem Sonogashira coupling reaction of aryl halides provides an efficient method for the synthesis of diarylalkynes. Several aryl halides were coupled with 2-methyl-3-butyn-2-ol as acetylene source in the presence of PdCl2(PPh3)2 and CuI. Following the deprotection of the acetylene moiety in the same pot using a strong base, the Sonogashira coupling of a second aryl halide led to the formation of the appropriate diarylakyne. The established protocoll was successfully extended to the preparation of compound libraries.