Gold-catalyzed dual C–C bond cleavage of biphenylenes bearing a pendant alkyne at ambient temperature

Abstract

<p>We report a catalytic skeletal rearrangement of biphenylenes with a pendant alkyne moiety at room temperature by a cationic gold catalyst, which involves the cleavage of two bonds: the C-C...</p>

Unusual Scaffold Rearrangement in Polyaromatic Hydrocarbons Driven by Concerted Action of Single Gold Atoms on a Gold Surface

“…In fact, only Au I -catalyzed ring opening of the strained biphenylenes has been reported so far. [23][24][25][26] Presumably, the whole process should be facilitated by participation of several single gold atoms on the Au(111) surface. This is supported by recent observations that the gold-catalyzed processes in solutions require concomitant participation of several gold atoms; for example, dinuclear gold catalysis.…”

“…Although small clusters of gold atoms can catalyze various chemical transformations, [20–22] the role of single gold‐adatoms in C−C bond activation and cleavage reactions is essentially unexplored. In fact, only Au I ‐catalyzed ring opening of the strained biphenylenes has been reported so far [23–26] . Presumably, the whole process should be facilitated by participation of several single gold atoms on the Au(111) surface.…”

Room-Temperature C–C σ-Bond Activation of Biphenylene Derivatives on Cu(111)

“… 38 In addition, high temperatures are usually required to break the C–C bond due to its strength. 13 Although C–C σ-bond metalation has been observed at room temperature, 12 , 14 achieving it with an earth-abundant metal such as Cu would open the field to more environmentally friendly metal catalysts, especially because the quasi-simultaneous cleavage and metal insertion into aryl C–C σ-bonds afford large atom economies 10 , 11 in multistep synthesis.…”

“…The unique structure of biphenylene, with two benzene rings fused to a strained antiaromatic cyclobutadiene (Scheme ), makes it an excellent candidate for C–C activation and further incorporation of the resulting 2,2′-biphenyl moiety into more complex polycyclic aromatic systems. ,,, Precious metals such as Au, − Pt, , Pd, ,, Ir, − and Rh − have been shown to cleave and insert onto the biphenylene σ-bond, generating active species for a diverse set of reactions , that includes dimerization, formal [4+2] or [4+1] cycloadditions, , or coupling reactions . Although this has also been observed by using earth-abundant metals such as Fe, , Co, Ni, − and Al to the best of our knowledge, biphenylene C–C bond activation has not yet been observed for Cu at room temperature.…”

“…38 In addition, high temperatures are usually required to break the C−C bond due to its strength. 13 Although C−C σ-bond metalation has been observed at room temperature, 12,14 achieving it with an earth-abundant metal Meanwhile, in the context of nanoscience, biphenylene remains largely untapped as a precursor in the blooming field of on-surface synthesis 39−43 (OSS) despite its rich solutionphase chemistry described above. OSS has produced and characterized graphenic 41 nanostructures with the aid of stateof-the-art scanning probe techniques.…”