1286737-75-4Relevant academic research and scientific papers
Synthesis and characterization of new ruthenium N-heterocyclic carbene Hoveyda II-type complexes. Study of reactivity in ring closing metathesis reactions
Merino, Estibaliz,Poli, Evelyne,Diaz, Urbano,Brunel, Daniel
, p. 10913 - 10918 (2012)
This manuscript describes the synthesis and structural study of new second generation Hoveyda-Grubbs catalysts: 1,3-dimesityl-acenaphthylenyl-4,5- imidazolin-2-ylidene (BIAN-NHC) ruthenium isopropoxybenzylidene dichloride 3 and 1,3-bis(2,6-dimethylphenyl)
Mild negishi cross-coupling reactions catalyzed by acenaphthoimidazolylidene palladium complexes at low catalyst loadings
Liu, Zelong,Dong, Ningning,Xu, Mizhi,Sun, Zheming,Tu, Tao
, p. 7436 - 7444 (2013/09/02)
Considering that the strong σ-donor property of ylidenes derived from π-extended imidazolium salts is conducive to increasing the catalytic activity of the resulting palladium N-heterocyclic carbene complexes, robust acenaphthoimidazol-ylidene palladium complexes 3a-c with varying bulky substituted groups were prepared from the corresponding acenaphthoimidazolium chlorides by heating with PdCl2 and K2CO3 in neat 3-chloropyridine in satisfactory yields. Even at a catalyst loading as low as 0.25 mol %, complex 3a exhibited extremely high catalytic activity toward Negishi cross-coupling of alkylzinc reagents with a wide range of (hetero)aryl halides under mild reaction conditions within 30 min. Besides a great number of bromoarenes, various less expensive and inactive (hetero)aryl chlorides were coupled successfully with the alkyl- and arylzinc reagents, in which active functional groups (such as -NH2) were well tolerated even in one-pot dicoupling transformations without protection. In addition, in the case of coupling with secondary alkylzinc reagents, undesired β-hydride elimination leading to isomerized linear products was efficaciously suppressed. The catalyst system also displayed superiority in the construction of heterobiaryls through the coupling of heteroarylzinc reagents and heterocylic chloroarenes which were hardly accessible from the corresponding organoboron reagents by Suzuki-coupling reactions. Therefore, the protocol described in this paper represents a mild, general, and scalable approach to access various structurally intriguing and functionalized (hetero)aryls.
Robust acenaphthoimidazolylidene palladium complexes: Highly efficient catalysts for suzuki-miyaura couplings with sterically hindered substrates
Tu, Tao,Sun, Zheming,Fang, Weiwei,Xu, Mizhi,Zhou, Yunfei
experimental part, p. 4250 - 4253 (2012/10/07)
Robust acenaphthoimidazolylidene palladium complexes have been demonstrated as highly efficient and general catalysts for the sterically hindered Suzuki-Miyaura cross-coupling reactions in excellent yields even with low catalyst loadings under mild reaction conditions. The high catalytic activity of these complexes highlights that, besides the "flexible steric bulky" concept, σ-donor properties of the NHC ligands are also crucial to accelerate the transformations.
