Acyclic diaminocarbenes (ADCs) as a promising alternative to N-heterocyclic carbenes (NHCs) in transition metal catalyzed organic transformations

Starting from the first reported application of complexes bearing acyclic diaminocarbene (ADC) ligands as catalysts ca. 5 years ago, these compounds have been successfully employed for several useful organic transformations, viz, cross-coupling reactions (Suzuki-Miyaura, Heck, Sonogashira. Buchwald-Hartwig. and Kumada) and some cyclizations/additions to substrates having the C C and C=C bonds. In these processes, ADC-metal complexes behave as an attractive alternative to extremely popular N-heterocyclic carbenes (NHCs). This review attempts to systematize studies published until now and to explain various observations and initial ideas on mechanisms and driving forces of ADC-based catalysts as well as to draw attention to the potential and the advantages that application of ADCs gives to synthetic organometallic and organic chemistry. (C) 2012 Elsevier B.V. All rights reserved.