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Mechanism of the Palladium‐Catalyzed Synthesis of Münchnones: The Role of Ligands in N ‐Acyl Iminium Salt Carbonylation
Author(s) -
Tjutrins Jevgenijs,
Dhawan Rajiv,
Lu Yingdong,
Arndtsen Bruce A.
Publication year - 2016
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201603400
Subject(s) - iminium , carbonylation , catalysis , mesoionic , chemistry , palladium , combinatorial chemistry , salt (chemistry) , organic chemistry , carbon monoxide
The palladium‐catalyzed carbonylative coupling of imines, acid chlorides, and dipolarophiles can provide efficient routes to prepare nitrogen‐containing heterocycles. One challenge in developing this reaction, and in the creation of more active catalyst systems, is the lack of data on how this complex transformation proceeds. To address this, we report here the results of our mechanistic studies on this system, and in particular the formation of mesoionic münchnones. This includes the synthesis of key catalytic intermediates, model reactions, and kinetic studies that support the role of these compounds in catalysis. Together, these studies provide a clear picture of the impact of catalyst structure, ligands, and palladium nanoparticles on facilitating the carbonylation of in situ generated iminium salts, and suggest an avenue for the creation of more active catalyst systems.