C–H Functionalization of BN-Aromatics Promoted by Addition of Organolithium Compounds to the Boron Atom

Abstract

Addition of an organolithium compound to a BN-phenanthrene with embedded B and N atoms is proposed to result in coordination of RLi to the boron atom. This coordination, supported by NMR spectroscopy and DFT calculations, increases the nucleophilicity of the system in the β position to the N atom and is therefore a useful tool for promoting regioselective C-H functionalization of BN aromatics.

Selectivity in the Elaboration of Bicyclic Borazarenes

“…This selectivity is suggested to arise from a radical mechanism, and is substantiated by evidence that Lewis acids are inconsequential to reaction progress and that the reaction is shut down with the addition of a radical trapping agent. 9,10‐Borazaronaphthalenes have also been demonstrated to undergo site‐selective deprotection with an alkyllithium reagent, which can then be trapped by an aldehyde electrophile [38] …”

Late-stage functionalization of BN-heterocycles

“…8 In 2018, Vaquero reported a complementary approach to the acylation reaction described by Fang and demonstrated the installation of an acyl group at the C1 position of 9,10-BNnaphthalene (Scheme 29). 28 Treating 52 with a strong base such as t-BuLi leads to deprotonation of the most acidic C1-proton (Scheme 29a). Subsequent treatment of the C1-lithiated BN heterocycle with aldehydes furnishes alcohols 57 in good yield.…”

Mono- and Dinitro-BN-Naphthalenes: Formation and Characterization

“…BN aromatics have been widely investigated in recent years since the materials pos sess attractive physical and chemical properties and hold potential applications in the light-emitting polymer [1][2][3][4][5][6][7][8][9][10][11][12], semiconductor [13][14][15][16][17], and other research fields [18][19][20][21][22][23][24][25][26][27][28][29] however, there have been relatively few reports on the synthesis of nitrated BN aromatics Thus far, only five mononitro-BN aromatics have been reported [30,31]. Dewar and their co-workers [30, in 1959, reported the first nitration of a BN aromatic, BN-phenanthrene (BNP), yielding a mixture of mononitro-substituted BNPs (1).…”

“…BN aromatics have been widely investigated in recent years since the materials possess attractive physical and chemical properties and hold potential applications in the light-emitting polymer [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ], semiconductor [ 13 , 14 , 15 , 16 , 17 ], and other research fields [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]; however, there have been relatively few reports on the synthesis of nitrated BN aromatics. Thus far, only five mononitro-BN aromatics have been reported [ 30 , 31 ].…”