S1 Cyclization Kinetics and Biological Evaluation of an Anticancer 1,2- Dialkynylimidazole Christophe Laroche, a Jing Li, a Cristina Gonzales, b Wendi M. David, b Sean M. Kerwin* a a Division of Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712, USA. *skerwin@mail.utexas.edu b Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX, 78666, USA Table of Contents: General Experimental p. S2 Optimization of the Copper-catalyzed coupling p. S2-S3 Characterization data for 1-3 p. S4–S5 1 H NMR Spectra for 1-3 p. S6–S8 13 C NMR Spectra for 1-3 p. S9–S10 X-ray crystallography of 3 p S11-S16 Cytotoxicity Studies of 3 p S17-19 Apoptosis assay p S20 DNA cleavage assay p S21 Peptide adduct assay p S22 Computational studies p S23-32 Kinetic studies p S33-S40 References p S41-S42