Investigations of the Copper‐Catalyzed Oxidative Cross‐Coupling of Tetrahydroisoquinolines with Diethylzinc by a Combination of Mass Spectrometric and Electrochemical Methods. Issue 11 (26th January 2018)

• Record Type: Journal Article
• Authors: Willms, J. Alexander; Gleich, Hermann; Schrempp, Michael; Menche, Dirk; Engeser, Marianne
• Is Part Of: Chemistry. Volume 24:Issue 11(2018)
• Page Start: 2663
• Page End: 2668
• Publication Date: 2018-01-26
• Subjects: cross-coupling -- Cu catalysis -- cyclic voltammetry -- electrospray mass spectrometry -- tetrahydroisoquinoline; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201704914
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: The aerobic oxidative cross‐coupling of tetrahydroisoquinolines (THIQs) with diethylzinc catalyzed by CuCl2 has been examined by means of electrospray mass spectrometry (ESI‐MS). Substrates, intermediates, and the product were readily detected. Particular emphasis has been placed on the role of CuCl2 . Formation of the intermediate iminium species has been investigated in more detail by ESI‐MS, electrochemistry‐coupled ESI mass spectrometry (EC‐MS), and cyclic voltammetry (CV). Our experiments have consistently revealed strong influences of the N‐substituent of the THIQ derivative and its oxidation stability with respect to CuCl2 . The results may help to expand the synthetic scope of the reaction, while also further establishing EC‐MS as a valuable technique for linking mass spectrometry with cyclic voltammetry in mechanistic studies of organic redox reactions. Abstract : Substrate screening beyond synthesis : Through a combination of electrospray mass spectrometry (ESI‐MS), online electrochemistry mass spectrometry (EC‐MS), and cyclic voltammetry (CV), mechanistic insight has been gained into the cross‐coupling of tetrahydroisoquinolines (THIQs) with diethylzinc.