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Salt‐Free Strategy for the Insertion of CO 2 into C−H Bonds: Catalytic Hydroxymethylation of Alkynes
Author(s) -
Wendling Timo,
Risto Eugen,
Krause Thilo,
Gooßen Lukas J.
Publication year - 2018
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.201800526
Subject(s) - catalysis , salt (chemistry) , chemistry , amine gas treating , alkyne , carboxylate , rhodium , copper , base (topology) , inorganic chemistry , polymer chemistry , organic chemistry , mathematical analysis , mathematics
Abstract A copper(I) catalyst enables the insertion of carbon dioxide into alkyne C−H bonds by using a suitable organic base with which hydrogenation of the resulting carboxylate salt with regeneration of the base becomes thermodynamically feasible. In the presence of catalytic copper(I) chloride/4,7‐diphenyl‐1,10‐phenanthroline, polymer‐bound triphenylphosphine, and 2,2,6,6‐tetramethylpiperidine as the base, terminal alkynes undergo carboxylation at 15 bar CO 2 and room temperature. After filtration, the ammonium alkynecarboxylate can be hydrogenated to the primary alcohol and water at a rhodium/molybdenum catalyst, regenerating the amine base. This demonstrates the feasibility of a salt‐free overall process, in which carbon dioxide serves as a C1 building block in a C−H functionalization.