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Diverse Reactivity of Dienes with Pentaphenylborole and 1‐Phenyl‐2,3,4,5‐Tetramethylborole Dimer
Author(s) -
Baker J. J.,
Al Furaiji Khadilah H. M.,
Liyanage O. Tara,
Wilson David J. D.,
Dutton Jason L.,
Martin Caleb D.
Publication year - 2019
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201805151
Subject(s) - diene , moiety , reactivity (psychology) , monomer , dimer , cycloaddition , chemistry , bicyclic molecule , polymer chemistry , medicinal chemistry , stereochemistry , organic chemistry , polymer , catalysis , medicine , natural rubber , alternative medicine , pathology
The reactions of a monomeric borole and a dimeric borole with 2,3‐dimethyl‐1,3‐butadiene and 1,3‐cyclohexadiene were investigated. The monomeric borole reacted at ambient temperature whereas heat was required to crack the dimer to form the monomer and induce reactivity. 2,3‐Dimethyl‐1,3‐butadiene reacts to give diverse products resulting from a cycloaddition process with the B−C moiety of the boroles acting as a dienophile, followed by rearrangements to furnish bicyclic species. For 1,3‐cyclohexadiene, a [4+2] process is observed in which 1,3‐cyclohexadiene serves as the dienophile and the boroles as the diene partner. The experimental results are corroborated with mechanistic theoretical calculations that indicate boroles can serve as either a diene or dienophile in cycloaddition reactions with dienes.