Sequential C−H Borylation and N‐Demethylation of 1,1′‐Biphenylamines: Alternative Route to Polycyclic BN‐Heteroarenes

Abstract

Described herein is an unprecedented access to BNpolyaromatic compounds from 1,1'-biphenylamines by sequential borane-mediated C(sp 2 )ÀHb orylation and intramolecular N-demethylation. The conveniently in situ generated Piers borane from ab orinic acid reacts with as eries of N,Ndimethyl-1,1'-biphenyl-2-amines in the presence of PhSiH 3 to affordsix-membered amine-borane adducts bearing aC(sp 2 )À Bb ond at the C2'-position. These species undergo an intramolecular N-demethylation with aB(C 6 F 5 ) 3 catalyst to provide BN-isosteres of polyaromatics.A ccording to computational studies,astepwise ionic pathway is suggested. Photophysical characters of the resultant BN-heteroarenes shown them to be distinctive from those of all-carbon analogues.

Elastic Molecular‐Assisted Fabrication of Orthorhombic Non‐Perovskite CsPbI2Br for Ultralow Dark Current in Advanced X‐Ray Imaging

“…This phenomenon can be attributed to the interface stress between the ITO substrate and the perovskite thick film. [ 31 ] To address this interface stress and enhance film quality, polymer layers of PI, PVP, and gelatin was employed to address the stress issues between perovskite and ITO. As shown in Figure S2 (Supporting Information), δ‐CsPbI 2 Br perovskite thick films with PI layer exhibits a smoother and more uniform morphology.…”

Regioselective Transition‐Metal‐Free C(sp2)−H Borylation: A Subject of Practical and Ongoing Interest in Synthetic Organic Chemistry

“…Park, Chang, and co‐workers recently introduced a different type of strategy for the amine‐directed C−H borylation of biphenylamine 57 . In this reaction, Piers’ borane (HB(C 6 F 5 ) 2 ) is initially generated in situ from a borinic acid and PhSiH 3 , which then undergoes C−H borylation at the C2′‐position of 57 with the aid of an NMe 2 auxiliary group to give 58 (Scheme 18c, up) [84] . Further exposing compound 58 to B(C 6 F 5 ) 3 results in the formation of the N‐demethylation and BN‐bonded polyaromatic compound 59 (Scheme 18c, bottom).…”

cine-Silylative Ring-Opening of α-Methyl Azacycles Enabled by the Silylium-Induced C–N Bond Cleavage

“…The procedure was readily expanded to the C− N bond cleavage of acyclic tertiary amines. 11 On the basis of integrated experimental and computational studies, a silyliuminvolved β-amino elimination was clarified as the crucial step.…”

“…20 As illustrated in Figure 2c, a second-order perturbation natural bond orbital (NBO) analysis of TS_ro was executed to reveal that the relatively low activation barrier was attributed to a considerable stabilization of TS_ro by means of a significant πdonation from the π-C2−C8 bond to the proximal silicon porbital, also known as the β-silicon effect. 21 According to the above experimental and computational rationale as well as the precedents, [3][4][5][6][10][11][12]14,17 In summary, we have developed an unprecedented boranecatalyzed cine-silylative ring-opening of α-methyl azacycles. The current B(C 6 F 5 ) 3 -catalyzed silylative transformation was found to operate for not only medium-sized azacycles but also acyclic tertiary amines.…”