AbstractCatalytic systems combining ortho‐(dimesitylboryl)phenylphosphines and palladium precursors have been evaluated in the Suzuki–Miyaura couplings of chloro‐N‐heterocycles, in particular 2‐chloropyridines, with arylboronic acids. The Lewis basic character of the substrates does not interfere with the Lewis acidic site of the ligands, even for a substrate featuring free NH2 groups. The influence of several reaction parameters has been studied and the ortho‐dimesitylboryl moiety was actually found to substantially enhance the catalytic performance. The role of this group has been examined using preformed phosphine‐borane/Pd complexes and the formation of an original phosphine/η4‐boratabutadiene complex has been identified as a possible deactivation pathway. Regioselective coupling of 2,6‐dichloro‐3‐nitropyridine with phosphine‐borane/Pd catalysts has also been explored, and sequential double cross‐couplings were found to give a direct and efficient access to unsymmetrical 2,6‐diarylpyridines.magnified image
Cooperative Lewis acidity in borane-substituted fluorophosphonium cations
作者:Juri Möbus、Thorsten vom Stein、Douglas W. Stephan
DOI:10.1039/c6cc02607a
日期:——
A series of aryl-difluorophosphoranes are converted to give fluorophosphonium salts [C6X4(BR2)Ph2PF]+ (X = H, F; R = Cy, Mes). The proximity of the two weakly Lewis acidic fluorophosphonium and borane...
一系列芳基-二氟膦酸酯被转化为氟phosph盐[C6X4(BR2)Ph2PF] +(X = H,F; R = Cy,Mes)。两个弱路易斯酸性氟phosph和硼烷的相近...
A Hexanuclear Gold Cluster Supported by Three-Center-Two-Electron Bonds and Aurophilic Interactions
作者:Ekaterina S. Smirnova、Antonio M. Echavarren
DOI:10.1002/anie.201303336
日期:2013.8.19
A heart of gold: The first hexanucleargoldcluster formed exclusively by gold(I) centers (see picture; Au yellow, C black, P purple) has been shown to be catalytically active for the activation of alkynes under homogeneous conditions.
Fluoride Ion Chelation By a Bidentate Phosphonium/Borane Lewis Acid
作者:Todd W. Hudnall、Young-Min Kim、Magnus W. P. Bebbington、Didier Bourissou、François P. Gabbaï
DOI:10.1021/ja804492y
日期:2008.8.1
These results, which are supported by NBO and AIM analyses, show that the latent phosphorus-centered Lewis acidity of the phosphonium moiety in [2]+ can be exploited to enhance fluoride binding via chelation.
A new insight into ortho-(dimesitylboryl)diphenylphosphines: applications in Pd-catalyzed Suzuki–Miyaura couplings and evidence for secondary π-interaction
ortho-(Dimesitylboryl)phenylphosphines1 and 2 were applied in Pd-catalyzed Suzuki-Miyaura C-C couplings. Coordination studies were performed in order to rationalize the relationship between structure and reactivity. Full characterization of a Pd(0) complex derived from 1 has evidenced a new coordination mode for phosphine-arylboranes involving secondary pi-interaction between one of the mesityl groups at boron
Singletdioxygen is readily split by phosphine–boronates under mild conditions. The initially formed phosphine peroxides spontaneously rearrange by B→O migration. The resulting peroxoboronates have been structurally characterized, and their ability to undergo oxygen transferreactions substantiated.