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Indexed by:期刊论文

Date of Publication:2018-06-21

Journal:CHEMCATCHEM

Included Journals:SCIE

Volume:10

Issue:12

Page Number:2686-2692

ISSN No.:1867-3880

Key Words:carbodicarbene; carbon dioxide fixation; cyclization; homogeneous catalysis; synthetic methods

Abstract:Four CO2 adducts of carbodicarbenes (CDCs) were first synthesized and structurally characterized by means of NMR spectroscopy, high-resolution mass spectrometry, and FTIR spectroscopy. The introduction of C-13-labelled CO2 confirmed the formation of the corresponding carboxylated species. Thermogravimetric analysis (TGA) provided detailed information on their thermal decarboxylation processes. The novel CDC-CO2 adducts were subsequently applied as robust and versatile organocatalysts for the carboxylative cyclization of CO2 with aziridines, epoxides, or propargylic alcohols, affording 2-oxazolidinones and cyclic carbonates in good to excellent yields (51-99%) and high functional group tolerance. TGA results together with control experiments indicate that the insitu formed free CDC by decarboxylation of the corresponding CDC-CO2 adducts plays the key role to activate the substrates by its strong Lewis basicity.