Ruthenium Catalysts for Hydrogenation of Aromatic and Aliphatic Esters: Make Use of Bidentate Carbene Ligands
作者:Felix A. Westerhaus、Bianca Wendt、Andreas Dumrath、Gerrit Wienhöfer、Kathrin Junge、Matthias Beller
DOI:10.1002/cssc.201200825
日期:2013.6
Committed carbenes: The convenient application of bidentatecarbeneligands is described for the hydrogenation of carboxylic acid esters. The ligand precursors are easily synthesized through the dimerization of N‐substituted imidazoles with diiodomethane. The catalyst is generated in situ and exhibits good activity and functional group tolerance for the hydrogenation of aromatic and aliphatic carboxylic
The phenol countdown: Novel imidazole‐based phosphineligands are synthesized on scales up to 100 g by a convenient lithiation–phosphorylation method. The phosphines are stable towards air and moisture and are successfully applied as ligands in the palladium‐catalyzed selectivehydroxylation of arylhalides (see scheme, dba=dibenzylideneacetone).
Metal-Free Selective Borylation of Arenes by a Diazadiborinine via C–H/C–F Bond Activation and Dearomatization
作者:Yuanting Su、Dinh Cao Huan Do、Yongxin Li、Rei Kinjo
DOI:10.1021/jacs.9b06022
日期:2019.9.4
A newly developed annulated 5-chlorinated 1,3,2,5-diazadiborinine derivative (4) selectively activates a C‒Hbond of benzene (C6H6) and 1,3-di(trifluoromethyl)benzene, as well as, a C‒F bond in par-tially fluorinated arenes, to furnish borylation products under the catalyst-, metal-, and irradiation-free condition. Moreover, (4) readily undergoes a reversible dearomative coupling reaction with polycyclic
Deprotonation of 1‐mesityl‐4,5‐diphenyl‐2‐imidazole 1 with nBuLi, followed by salt metathesis reaction with GeCl2·dioxane complex, led to the formation of the chlorogermyliumylidene 2 bearing two Ge–Cl units, which has been isolated and fully characterized by standard spectroscopic and X‐ray diffraction analysis. Structural and NMR spectroscopic data as well as computational studies revealed that the
Oxidative addition of elemental selenium to 1,4,2,5-diazadiborinine
作者:Gillian Kor Hwee Goh、Yongxin Li、Rei Kinjo
DOI:10.1039/c9dt01081e
日期:——
synthesized and fully characterized. Computational studies revealed that compound 3 features a relatively small HOMO–LUMO gap (2.61 eV). When 3 was treated with elemental grey selenium (Se), oxidativeaddition of Se proceeded regioselectively at the boron centres of 3 to give a bicyclo[2.2.2] molecule 4 involving a B–Se–Se–B unit, which can be deemed a heavier analogue of dibora-peroxide.