1-Heteroaromatic-Substituted Tetraphenylboroles: π–π Interactions Between Aromatic and Antiaromatic Rings Through a B–C Bond
摘要:
A series of 2,3,4,5-tetraphenylboroles substituted with different aromatic heterocycles (thiophene, furan, pyrrole, and dithiophene) in the 1-position were synthesized and characterized by means of NMR, elemental analysis, and X-ray crystallography. In contrast to known 2,3,4,5-tetraphenylboroles, X-ray diffraction revealed a nearly coplanar arrangement of the aromatic heterocycles and the antiaromatic borole scaffold as a result of pi-conjugation, which could be substantiated by DFT calculations. Furthermore, the 2,2'-dithiophene-bridged bisborole (14) exhibits a large bathochromic shift in the absorption spectrum, demonstrating the exceptional Lewis acidity of the nonannulated borolyl moiety.
Adducts of the Parent Boraphosphaketene H
<sub>2</sub>
BPCO and their Decarbonylative Insertion Chemistry
作者:Stephan Hagspiel、Felipe Fantuzzi、Rian D. Dewhurst、Annalena Gärtner、Felix Lindl、Anna Lamprecht、Holger Braunschweig
DOI:10.1002/anie.202103521
日期:2021.6.7
cyclodimers are prepared. One of these adducts is shown to undergo mild decarbonylation and phosphinidene insertion into a B−C bond of a borole, forming very rare examples of 1,2-phosphaborinines, B/P isosteres of benzene. The strong donor properties of these 1,2-phosphaborinines are confirmed by the synthesis of their π complexes with the Group 6 metals.
Scope of the Thermal Ring-Expansion Reaction of Boroles with Organoazides
作者:Holger Braunschweig、Mehmet Ali Celik、Theresa Dellermann、Gernot Frenking、Kai Hammond、Florian Hupp、Hauke Kelch、Ivo Krummenacher、Felix Lindl、Lisa Mailänder、Jonas H. Müssig、Annika Ruppert
DOI:10.1002/chem.201700749
日期:2017.6.12
steric factors have been investigated in the thermal ring expansion of boroles with organic azides, a reaction that provides access to highly arylated 1,2-azaborinines, BN analogues of benzene. Reactions of a variety of boroles and organic azides demonstrate that the synthetic method is quite general in furnishing 1,2-azaborinines, but the respective reaction rates reveal a strong dependence on the substituents
A new isomer of borepin, identified as 2‐borabicyclo[3.2.0]hepta‐3,6‐diene by single‐crystal X‐ray diffraction and heteronuclear NMR spectroscopy, was obtained by reaction of 1‐mesityl‐2,3,4,5‐tetraphenylborole with the diaminoalkyne bis(piperidyl)acetylene. Analogous reactions of the alkyne with other borole derivatives generated seven‐membered borepins, in which a second equivalent of the alkyne