Polare Iminoborane: Reaktionen des ( tert ‐Butylimino)(pentafluorphenyl)borans
1995; Wiley; Volume: 128; Issue: 10 Linguagem: Inglês
10.1002/cber.19951281012
ISSN0009-2940
AutoresC. Klofkorn, Martin U. Schmidt, Thomas P. Spaniol, Trixie Wagner, Otilia Costişor, Peter Paetzold,
Tópico(s)Inorganic Fluorides and Related Compounds
ResumoAbstract Polar Iminoboranes: Reactions of ( tert ‐Butylimino)(pentafluorophenyl)borane The reactions of the iminoborane C 6 F 5 ‐B≡N‐ t Bu ( 1 ) with nitriles and isonitriles are studied. Nitriles RCN give cycloadducts either of the triazadiboracyclohexane type ( 3a ; R = i Pr) or of the tetrazatriborabicyclo[4.2.0]octane type [ 4b‐d ; R = Ph, p ‐C 6 H 4 Me, p ‐C 6 H 4 (CF 3 )] or of the (iminomethyl)borazine type ( 5e, f ; R = Me, Et). Isonitriles RNC yield mainly adducts of RNC to a cycloaddition product of the diazadiboracyclopentane type ( 6a, b ; R = 2,6‐C 6 H 3 Me 2 , t Bu); the adduct of RNC to a diazadiboracyclobutane may be a side‐product ( 7b ; R = t Bu). The iminoborane Me 3 Si( t Bu)N‐B=N t Bu reacts with two molecules of (2,6‐C 6 H 3 Me 2 )NC to give the corresponding azaboracyclobutane 8. The iminoborane t Bu‐B≡N‐C 6 F 5 ( 1 ′), formed by gas‐phase elimination of ClSiMe 3 from Cl( t Bu)B = N(C 6 F 5 )SiMe 3 ( 9 ), cyclodimerizes more readily than the isomeric borane 1. The cyclodimer 2 ′ gives 1:1‐addition reactions with t BuNC, PMe 3 , and MeNC, respectively; the added components fluctuate in solutions of the products 7b'‐d '. A similar fluctuation is observed with the 1:1 adduct 7c from PMe 3 and the cyclodimer 2 of the iminoborane 1. The products 3a, 5e, 6a, 8 crystallize in the space groups P 2 1 / c , P 2 1 / n , Pbca , and P 2 1 / c , respectively.
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