Cargando…

Synthesis, bridgehead functionalization, and photoisomerization of 9,10-diboratatriptycene dianions

9,10-Diboratatriptycene salts M(2)[RB(μ-C(6)H(4))(3)BR] (R = H, Me; M(+) = Li(+), K(+), [n-Bu(4)N](+)) have been synthesized via [4 + 2] cycloaddition between doubly reduced 9,10-dihydro-9,10-diboraanthracenes M(2)[DBA] and benzyne, generated in situ from C(6)H(5)F and C(6)H(5)Li or LiN(i-Pr)(2). [H...

Descripción completa

Detalles Bibliográficos
Autores principales: Prey, Sven E., Gilmer, Jannik, Teichmann, Samira V., Čaić, Luis, Wenisch, Mischa, Bolte, Michael, Virovets, Alexander, Lerner, Hans-Wolfram, Fantuzzi, Felipe, Wagner, Matthias
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society of Chemistry 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10207881/
https://www.ncbi.nlm.nih.gov/pubmed/37234897
http://dx.doi.org/10.1039/d3sc00555k
Descripción
Sumario:9,10-Diboratatriptycene salts M(2)[RB(μ-C(6)H(4))(3)BR] (R = H, Me; M(+) = Li(+), K(+), [n-Bu(4)N](+)) have been synthesized via [4 + 2] cycloaddition between doubly reduced 9,10-dihydro-9,10-diboraanthracenes M(2)[DBA] and benzyne, generated in situ from C(6)H(5)F and C(6)H(5)Li or LiN(i-Pr)(2). [HB(μ-C(6)H(4))(3)BH](2−) reacts with CH(2)Cl(2) to form quantitatively the bridgehead-derivatized [ClB(μ-C(6)H(4))(3)BCl](2−), while twofold H(−) abstraction with B(C(6)F(5))(3) in the presence of SMe(2) leads cleanly to the diadduct (Me(2)S)B(μ-C(6)H(4))(3)B(SMe(2)). Photoisomerization of K(2)[HB(μ-C(6)H(4))(3)BH] (THF, medium-pressure Hg lamp) provides facile access to diborabenzo[a]fluoranthenes, a little explored form of boron-doped polycyclic aromatic hydrocarbons. According to DFT calculations, the underlying reaction mechanism consists of three main steps: (i) photoinduced di-π-borate rearrangement, (ii) “walk reaction” of a BH unit, and (iii) boryl anion-like C–H activation.