Multidentate NHC complexes of group IX metals featuring carbon-based tethers: Synthesis and applications

Self-Isomerized–Cyclometalated Rhodium NHC Complexes as Active Catalysts in the Hydrosilylation of Internal Alkynes

“…Transition-metal complexes containing N-heterocyclic carbenes (NHCs) have been powerful tools in catalysis for the past 20 years, − with a wide variety of applications illustrating the general versatility of the metal NHC complexes. Even though rhodium is currently the most expensive member of the group IX transition metals, it is one of the most studied due to its high activity and stability . Of the group IX metals, rhodium has proven to be the most active for C–H activation − in addition to being active for C–O, − C–C, and C–N , activation reactions. , This was also observed in the work we describe herein, where a tandem isomerization/cyclometalation occurred via C–H bond activation of the N -tethered β-methyl allyl group on the NHC ligand.…”

“…Even though rhodium is currently the most expensive member of the group IX transition metals, it is one of the most studied due to its high activity and stability. 5 Of the group IX metals, rhodium has proven to be the most active for C−H activation 6−13 in addition to being active for C−O, 14−16 C−C, 17 and C−N 18,19 activation reactions. 5,20 This was also observed in the work we describe herein, where a tandem isomerization/cyclometalation occurred via C−H bond activation of the N-tethered βmethyl allyl group on the NHC ligand.…”

“…5 Of the group IX metals, rhodium has proven to be the most active for C−H activation 6−13 in addition to being active for C−O, 14−16 C−C, 17 and C−N 18,19 activation reactions. 5,20 This was also observed in the work we describe herein, where a tandem isomerization/cyclometalation occurred via C−H bond activation of the N-tethered βmethyl allyl group on the NHC ligand. Inspired by these results, we decided to apply these complexes to one of the lesser studied hydrogenation reactions: namely, the hydrosilylation of internal alkynes.…”

Synthesis, characterization and biological evaluation of Bis-benzimidazolium salts and their silver(I)-N-heterocyclic carbene complexes

“…Since the synthesis of rst N-heterocyclic carbene by Öfele and Wanzlick in 1968 [1,2] and the isolation of rst stable NHC by Arduengo in 1991 [3], the synthesis of new N-heterocyclic carbenes and their complexes gained a great research interest. It is an attractive research eld where a range of new metal-NHC complexes involving main group elements and transition metals have been synthesized and applied in different areas of interest [4][5][6][7]. NHCs are similar to phosphine ligands in how they coordinate with metals.…”

Rhodium and Iridium Mediated C-H and O-H Bond Activation of Two Schiff Base Ligands: Synthesis, Characterization and Catalytic Properties of the Organometallic Complexes

“…The chemistry of rhodium and iridium has been receiving considerable current attention ( Chi et al, 2017 ; Colombo et al, 2020 ; Mao et al, 2020 ; Shaikh et al, 2020 ; Alsalahi and Trzeciak, 2021 ; Davison et al, 2021 ; Monti et al, 2021 ; Vuuren et al, 2021 ), largely because of the interesting properties exhibited by the complexes of these metals. As properties of the complexes are dictated primarily by the coordination environment around the metal center, complexation of rhodium by ligands of selected types has been of significant importance, and the present work has originated from our interest in this area ( Dutta et al, 2000a ; Dutta et al, 2000b ; Das et al, 2002 ; Dutta et al, 2002 ; Acharyya et al, 2004a ; Acharyya et al, 2004b ; Acharyya et al, 2005 ; Acharyya et al, 2006 ; Basu et al, 2006 ; Baksi et al, 2007a ; Basu et al, 2007 ; Baksi et al, 2007b ; Dasgupta et al, 2008 ; GuhaRoy et al, 2008 ; Acharyya et al, 2009 ; GuhaRoy et al, 2009 ; Baksi et al, 2010 ; Basu et al, 2010 ; Majumder et al, 2011 ; Seth and Bhattacharya, 2011 ; Bhattacharya et al, 2012 ; Paul and Bhattacharya, 2012 ; Sengupta and Bhattacharya, 2013 ; Paul et al, 2014 ).…”