Heterocyclische Carbene – Synthese und Koordinationschemie

Abstract

Die Chemie der heterocyclischen Carbene hat sich in den letzten Jahren stürmisch entwickelt. Nach den Imidazolin‐2‐ylidenen wurden weitere cyclische Diaminocarbene mit unterschiedlichen Ringgrößen beschrieben. Neben den Diaminocarbenen sind auch P‐heterocyclische Carbene sowie Derivate mit nur einem oder gar keinem Heteroatom im Carbenring bekannt. Gleichzeitig sind zahlreiche neue Methoden zur Synthese von Komplexen heterocyclischer Carbene, wie die oxidative Addition oder die Cyclisierung von β‐funktionalisierten Isocyaniden an einem Metalltemplat, etabliert worden. Dieser Aufsatz fasst die Fortschritte bei der Synthese von heterocyclischen Carbenen und ihren Komplexen zusammen.

Study on the Reactivity of Aldehydes in Electrolyzed Ionic Liquids: Benzoin Condensation – Volatile Organic Compounds (VOCs) vs. Room Temperature Ionic Liquids (RTILs)

“…have been emphasized. [8] In the last years, we have reported an alternative electrochemical procedure, able to produce N-heterocyclic carbenes in the absence of bases as well of VOCs. [9] 1-Butyl-3-methylimidazol-2-ylidene has been obtained by cathodic reduction of 1-butyl-3-methylimidazolium cation.…”

Appel reagent as novel promoter for the synthesis of polysubstituted imidazoles

“…These compounds act as organic catalysts, 1 precursors of ionic liquids 2 and carbene ligands, 3 building blocks of complex meaningful molecules and natural products, 4 and ligands in metalloenzymes. 5 The imidazole core exists in many compounds with pharmaceutical and biological activity such as losartan, eprosartan, carnosinemia, histamine, and histidine.…”

An Efficient and Green Synthesis of Imidazoles Using Natural Organic Acids as Promoter under Solvent-Free Condition

“…[16] and also as pesticides [17]. Recent advances in green chemistry and organometallic catalysis has extended the application of imidazoles as ionic liquids [18] and N-heterocyclic carbenes [19]. Due to their wide range of pharmacological activity, industrial and synthetic applications, a number of methods [20][21][22] have been reported for the synthesis of imidazoles and its derivatives.…”