Functionalization of N₂ via Formal 1,3‐Haloboration of a Tungsten(0) σ‐Dinitrogen Complex

Abstract

Boron tribromide and aryldihaloboranesw ere found to undergo 1,3-haloboration across one WÀNN moiety of ag roup 6e nd-on dinitrogen complex (i.e. trans-[W(N 2) 2 (dppe) 2 ]). The N-borylated products consist of ar educed diazenido unit sandwiched between aW II center and at rivalent boron substituent (WÀN=NÀBXAr), and have all been fully characterized by NMR andI Rs pectroscopy,e lementala nalysis, and single-crystal X-ray diffraction. Both the terminal Na tom and boronc enteri nt he WÀN=NÀBXAr unit can be further derivatizedu sing electrophiles and nucleophiles/Lewis bases, respectively.T his mild reduction and functionalization of aw eakly activated N 2 ligand with boron halides is unprecedented, and hints at the possibility of generatingv alue-added nitrogen compounds directly from molecular dinitrogen.

Understanding, Modulating, and Leveraging Transannular M → Z Interactions

“…Taken together, our results show that all four ligands form stabilizing interactions with the nickelatranes due to a combination of electrostatic, bonding, and dispersion interactions. These are increased if the heavier group 13 atoms are positioned in the bridgehead position, a strategy that becomes particularly relevant for the activation and functionalization of less reactive species, such as N 2 , which agrees with earlier experimental studies …”

Transition metal-mediated dinitrogen functionalisation with boron

“…The group of Braunschweig has recently shown that the W complex 21 is also reactive towards tri-and dihalo(aryl)boranes. 22 The latter reacted with 21 through a formal 1,3-haloboration, allowing the preparation of boryldiazenido compounds 33 and Ar 34-X (Scheme 9). Chloroboranes reacted more sluggishly than the bromo derivatives.…”

Catalytic Reduction of N2 to Borylamine at a Molybdenum Complex

“…Complex 3 was isolated as a greenish solid in a very good 80 % yield and characterized by multinuclear NMR spectroscopy. No signal was observed in the 11 B{ 1 H} spectrum, as often encountered for tricoordinated B centers, especially when they are bonded to a quadrupolar center such as N [37] . X‐ray diffraction analysis of crystals obtained by diffusion of pentane into a THF solution of the complex provided definitive proof of the proposed structure (Supporting Information) [43] .…”

“…Simonneau further explored this reactivity using strongly electrophilic derivative (C 6 F 5 ) 2 BH [35, 36] . In 2020, Braunschweig reported the 1,3 addition of a B−Br bond across a W‐NN moiety [37] . Using early transition metals, Fryzuk achieved the 1,2 B‐H addition on N 2 at a bimetallic Ta complex, [38] while Chirik observed the formation of a N−B bond and bridging hydride starting from a side on MN 2 M (M=Zr, Hf) complex [39] .…”

“…[35,36] In 2020, Braunschweig reported the 1,3 addition of a B À Br bond across a W-NN moiety. [37] Using early transition metals, Fryzuk achieved the 1,2 B-H addition on N 2 at a bimetallic Ta complex, [38] while Chirik observed the formation of a NÀB bond and bridging hydride starting from a side on MN 2 M (M = Zr, Hf) complex. [39] We have also made a significant contribution to this field upon showing that a Mo-nitrido complex, obtained by direct splitting of N 2 , reacts towards mild electrophiles such as PinBH (PinBH = 4,4,5,5-tetramethyl-1,3,2-dioxaborolane), [40,41] to afford borylamines via stepwise functionalization of the N center.…”