title: Reactions of Boron-Derived Radicals with Nucleophiles.
abstract: Reactions of phenanthrenedione- and pyrenedione-derived borocyclic radicals, CnH8O2B(C6F5)2•(n = 14 (1), 16 (3)), with a variety of nucleophiles have been studied. Reaction of 1 with P(t-Bu)3affords the zwitterion 3-(t-Bu)3PC14H7O2B(C6F5)2(5) in addition to the salt [HP(t-Bu)3][C14H8O2B(C6F5)2] (6). In contrast, the reaction of 1 with PPh3proceeds to give two regioisomeric zwitterions, 1-(Ph3P)C14H7O2B(C6F5)2(7a) and 3-(Ph3P)C14H7O2B(C6F5)2(7b), as well as the related boronic ester C14H8O2B(C6F5) (2). In a similar fashion, 3 reacted with PPh3to give 3-(Ph3P)C16H7O2B(C6F5)2(8a), 1-(Ph3P)C16H7O2B(C6F5)2(8b), and boronic ester C16H8O2B(C6F5) (4). Reactions of secondary phosphines Ph2PH and tBu2PH with 3 yield 3-(R2PH)C16H7O2B(C6F5)2(R = Ph (9), t-Bu (10)). The reaction of 1 with N-heterocyclic carbene IMes afforded 3-(IMes)C14H7O2B(C6F5)2(11) and [IMesH][C14H8O2B(C6F5)2] (12), while the reactions with quinuclidine and DMAP afforded the species 3-(C7H13N)C14H7O2B(C6F5)2(13) and [H(NC7H13)2][C14H8O2B(C6F5)2] (14), and the salt [9,10-(DMAP)2C14H8O2B(C6F5)2][C14H8O2B(C6F5)2] (15), respectively. These products have been fully characterized, and the mechanism for the formation of these products is considered in the light of DFT calculations.
authors.affiliation: Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Longobardi
authors.affiliation: Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Pavel
authors.initials: P
authors.lastname: Zatsepin
authors.affiliation: Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Roman
authors.initials: R
authors.lastname: Korol
authors.affiliation: Mulliken Center for Theoretical Chemistry, Institut fuer Physikalische und Theoretische Chemie, Universitaet Bonn , Beringstrasse 4, D-53115 Bonn, Germany.
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.affiliation: Mulliken Center for Theoretical Chemistry, Institut fuer Physikalische und Theoretische Chemie, Universitaet Bonn , Beringstrasse 4, D-53115 Bonn, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Grimme
authors.affiliation: Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Douglas W
authors.identifier: 0000-0001-8140-8355
authors.initials: DW
authors.lastname: Stephan