Ambler, Brett R.Peddi, SantoshAltman, Ryan A.2017-03-232017-03-232015-05-17Ambler, B. R., Peddi, S., & Altman, R. A. (2015). Ligand-controlled Regioselective Cu-Catalyzed Trifluoromethylation to Generate Trifluoromethylallenes. Organic Letters, 17(10), 2506–2509. http://doi.org/10.1021/acs.orglett.5b01027https://hdl.handle.net/1808/23474“Cu–CF3” species have been used historically for a broad spectrum of nucleophilic trifluoromethylation reactions. Although recent advancements have employed ligands to stabilize and harness the reactivity of this key organometallic intermediate, the ability of a ligand to differentiate a regiochemical outcome of a Cu–CF3-mediated or -catalyzed reaction has not been previously reported. Herein, we report the first example of a Cu-catalyzed trifluoromethylation reaction in which a ligand controls the regiochemical outcome. More specifically, we demonstrate the ability of bipyridyl-derived ligands to control the regioselectivity of the Cu-catalyzed nucleophilic trifluoromethylation reactions of propargyl electrophiles to generate trifluoromethylallenes. This method provides a variety of di-, tri- and tetra-substituted trifluoromethylallenes, which can be further modified to generate complex fluorinated substructures.This document is the Accepted Manuscript version of a Published Work that appeared in final form in Organic Letters, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/acs.orglett.5b01027.Article10.1021/acs.orglett.5b01027openAccess