... Please enable JavaScript to use all the features on this page. Tetrahedron Letters. Volume 54, Issue 48, 27 November 2013, Pages 6524–6528. Cover image Cover image. A copper-free, cross-coupling of terminal alkynes with hetaryl halides. ... 2013. Abstract. Substituted ethynyl heterocycles and heteroarylbutenynes are synthesized efficiently in good yields via a copper-free, cross-coupling reaction. Graphical abstract. ... Tetrahedron Lett., 46 (2005), pp. 3557– ...