Boron Insertion into the N≡N Bond of a Tungsten Dinitrogen Complex

Abstract

The 1,3-addition of 1,2-diaryl-1,2-dibromodiboranes (B 2 Br 2 Ar 2 ) to trans-[W(N 2 ) 2 (dppe) 2 ] (dppe = κ 2 -(Ph 2 PCH 2 ) 2 ), which is accompanied by a Br−Ar substituent exchange between the two boron atoms, is followed by a spontaneous rearrangement of the resulting tungsten diboranyldiazenido complex to a 2-aza-1,3-diboraallenylimido complex displaying a linear, cumulenic B=N=B moiety. This rearrangement involves the splitting of both the B−B and N=N bonds of the N 2 B 2 ligand, formal insertion of a BAr boranediyl moiety into the N=N bond, and coordination of the remaining BArBr boryl moiety to the terminal nitrogen atom. Density functional theory calculations show that the reaction proceeds via a cyclic NB 2 intermediate, followed by dissociation into a tungsten nitrido complex and a linear boryliminoborane, which recombine by adduct formation between the nitrido ligand and the electron-deficient iminoborane boron atom. The linear B=N=B moiety also undergoes facile 1,2-addition of Brønsted acids (HY = HOPh, HSPh, and H 2 NPh) with concomitant Y−Br substituent exchange at the terminal boron atom, yielding cationic (borylamino)borylimido tungsten complexes.

All‐Inorganic sp‐Chain Ligands: Isoelectronic B/N Analogues of E. O. Fischer's Alkynylcarbynes

“…Building on earlier work from Hidai et al., [19] our group [20–22] and that of Simmoneau [23–26] have recently made inroads into the hydro‐ and haloborylation of transition‐metal‐bound N 2 ligands to form boryldiazenido complexes of the form [L n W=N=N(BXY)] (X,Y=anionic substituent) [27] . In particular, we have isolated a number of species in which the boron atom bears one or two halide substituents.…”

“…Building on earlier work from Hidai et al, [19] our group [20][21][22] and that of Simmoneau [23][24][25][26] substituent). [27] In particular, we have isolated a number of species in which the boron atom bears one or two halide substituents.…”

Vollständig anorganische sp‐Kettenliganden: Isoelektronische B/N‐Analoga von E. O. Fischers Alkinylcarbinen

“…Aufbauend auf früheren Arbeiten von Hidai et al [19] haben unsere Gruppe [20][21][22] und die von Simmoneau [23][24][25][26] kürzlich Fortschritte bei der Hydro-und Haloborylierung von Übergangsmetall-gebundenen N 2 -Liganden zur Bildung von Boryldiazenidokomplexen der Form [L n W=N=N-(BXY)] (X, Y = anionischer Substituent) gemacht. [27] Insbesondere haben wir eine Reihe von Spezies isoliert, in welchen das Boratom einen oder zwei Halogenidsubstituenten trägt.…”