Mandal, Tanmoy; Yadav, Sudha; Choudhury, Joyanta published their research in Journal of Organometallic Chemistry in 2021. The article was titled 《Steric effect of NHC ligands in Pd(II)-NHC-catalyzed non-directed C-H acetoxylation of simple arenes》.Application In Synthesis of 1,3-Dimesityl-1H-imidazol-3-ium chloride The article contains the following contents:
Herein, a series of well-defined discrete [Pd(NHCRR1)(py)I2] complexes I [R = Me, Cy, n-Bu, Mes; R1 = Me, Cy, n-Bu, Mes, t-Bu, Ph; RR1 = Me, Cy, n-Bu, Mes] with systematically varied degree of spatial congestion at the Pd center, exerted through the R and R1 substituents on the NHC ligand, were explored in controlling the activity as well as the site-selectivity of non-directed acetoxylation of representative monosubstituted and disubstituted simple arenes (such as toluene, iodobenzene and bromobenzene, naphthalene and 1,2-dichlorobenzene). The resulting best yields were found to be 75% for toluene and 65% for bromobenzene with [Pd(NHCPhMe)(py)I2], 75% for iodobenzene and 79% for naphthalene with [Pd(NHCMeMe)(py)I2], and 41% for 1,2-dichlorobenzene with [Pd(NHCCyCy)(py)I2]. Most importantly, with increasing the bulkiness of the NHC ligand in the complexes, the selectivity of the distal C-acetoxylated products in comparison to the proximal ones, was enhanced to a great extent in all cases. Considering the vast library of NHC ligands, this study underscores the future opportunity to develop more strategies to improve the activity and the crucial site-selectivity of C-H functionalization reactions in simple as well as complex organic mols. The experimental part of the paper was very detailed, including the reaction process of 1,3-Dimesityl-1H-imidazol-3-ium chloride(cas: 141556-45-8Application In Synthesis of 1,3-Dimesityl-1H-imidazol-3-ium chloride)
1,3-Dimesityl-1H-imidazol-3-ium chloride(cas: 141556-45-8) is a ligand for arylation of aldehydes and for carbene catalyzed intermolecular arylation of C-H bonds. It is used as a phosphine-free ligand in various metal-catalyzed coupling reactions, often with advantageous results in difficult cases.Application In Synthesis of 1,3-Dimesityl-1H-imidazol-3-ium chloride
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem