144432-80-4Relevant articles and documents
Multimetallic catalysed cross-coupling of aryl bromides with aryl triflates
Ackerman, Laura K. G.,Lovell, Matthew M.,Weix, Daniel J.
, p. 454 - 457 (2015)
The advent of transition-metal catalysed strategies for forming new carbon-carbon bonds has revolutionized the field of organic chemistry, enabling the efficient synthesis of ligands, materials, and biologically active molecules. In cases where a single metal fails to promote a selective or efficient transformation, the synergistic cooperation of two distinct catalysts - multimetallic catalysis - can be used instead. Many important reactions rely on multimetallic catalysis, such as the Wacker oxidation of olefins and the Sonogashira coupling of alkynes with aryl halides, but this approach has largely been limited to the use of metals with distinct reactivities, with only one metal catalyst undergoing oxidative addition. Here, we demonstrate that cooperativity between two group 10 metal catalysts - (bipyridine)nickel and (1,3-bis(diphenylphosphino)propane)palladium - enables a general cross-Ullmann reaction (the cross-coupling of two different aryl electrophiles). Our method couples aryl bromides with aryl triflates directly, eliminating the use of arylmetal reagents and avoiding the challenge of differentiating between multiple carbon-hydrogen bonds that is required for direct arylation methods. Selectivity can be achieved without an excess of either substrate and originates from the orthogonal reactivity of the two catalysts and the relative stability of the two arylmetal intermediates. While (1,3-bis(diphenylphosphino)propane)palladium reacts preferentially with aryl triflates to afford a persistent intermediate, (bipyridine)nickel reacts preferentially with aryl bromides to form a transient, reactive intermediate. Although each catalyst forms less than 5 per cent cross-coupled product in isolation, together they are able to achieve a yield of up to 94 per cent. Our results reveal a new method for the synthesis of biaryls, heteroaryls, and dienes, as well as a general mechanism for the selective transfer of ligands between two metal catalysts. We anticipate that this reaction will simplify the synthesis of pharmaceuticals, many of which are currently made with pre-formed organometallic reagents, and lead to the discovery of new multimetallic reactions.
Sequential dehydrogenation-arylation of diisopropylamine-borane complex catalyzed by palladium nanoparticles
Guerrand, Hélène D.S.,Marciasini, Ludovic D.,Gendrineau, Thomas,Pascu, Oana,Marre, Samuel,Pinet, Sandra,Vaultier, Michel,Aymonier, Cyril,Pucheault, Mathieu
, p. 6156 - 6161 (2014)
Palladium nanoparticles have been prepared using different techniques, CO2-assisted microfluidics coflow or thermolysis using ionic liquids. Both techniques displayed interesting activities in dehydrogenation of diisopropylamine-borane complex, and allowed performing a dehydrogenation-arylation sequence with the creation of a carbon-boron bond.
Unreactive C-N Bond Activation of Anilines via Photoinduced Aerobic Borylation
Ji, Shuohan,Qin, Shengxiang,Yin, Chunyu,Luo, Lu,Zhang, Hua
supporting information, p. 64 - 68 (2021/12/27)
Unreactive C-N bond activation of anilines was achieved by photoinduced aerobic borylation. A diverse range of tertiary and secondary anilines were converted to aryl boronate esters in moderate to good yields with wide functional group tolerance under simple and ambient photochemical conditions. This transformation achieved the direct and facile C-N bond activation of unreactive anilines, providing a convenient and practical route transforming widely available anilines into useful aryl boronate esters.
Photoinduced Deaminative Borylation of Unreactive Aromatic Amines Enhanced by CO2
Shiozuka, Akira,Sekine, Kohei,Kuninobu, Yoichiro
supporting information, p. 4774 - 4778 (2021/06/28)
Herein, direct unreactive C-N borylation of aromatic amines by a photocatalyst was achieved. The C-N borylation of aromatic amines with bis(pinacolato)diboron (B2pin2) proceeded using a pyrene catalyst under light irradiation to afford desired borylated products and aminoborane as a byproduct. The yield of the borylated product improved under a CO2 atmosphere which probably reduced the inhibitory effect of aminoborane. Mechanistic studies suggested that the C-N bond cleavage and C-B bond formation proceeded via a concerted pathway.
