A Low‐Valent Molybdenum Nitride Complex: Reduction Promotes Carbonylation Chemistry

Abstract

Toward nitrogen functionalization, reactive terminal transition metal nitrides with high d‐electron counts are of interest. A series of terminal MoIV nitride complexes were prepared within the context of exploring nitride/carbonyl coupling to cyanate. Reduction affords the first MoII nitrido complex, an early metal nitride with four valence d‐electrons. The binding mode of the para‐terphenyl diphosphine ancillary ligand changes to stabilize an electronic configuration with a high electron count and a formal M−N bond order of three. Even with an intact Mo≡N bond, this low‐valent nitrido complex proves to be highly reactive, readily undergoing N‐atom transfer upon addition of CO, releasing cyanate anion.

Cyanate Formation via Photolytic Splitting of Dinitrogen

“…The enhanced reactivity of the photolytically produced nitride was demonstrated by near quantitative nitride carbonylation at ambient conditions. Isocyanate formation from nitride complexes and CO was previously reported in several instances, 101 − 109 yet only for one example coupled to N 2 splitting. 88 In that case, selective carbonylation of the N 2 splitting product required oxidation from V IV /V IV to V V /V V .…”

Divalent Titanium via Reductive N−C Coupling of a TiIV Nitrido with π‐Acids

“…Unfortunately, the proclivity of early‐transition metal nitrides to bridge or oligomerize precludes their extensive reactivity studies [10,11] . Although early‐transition metal nitrides are nucleophilic at the N‐center and exhibit reactivity with various electrophiles, [12,13] reductive N−C coupling with π‐acids, such as CO and isocyanides, has been underexplored, despite the utility of the resulting new N−C coupled products in organic synthesis [1g,5a–d] . Moreover, the stabilization and concurrent reactivity study of the resulting low‐valent metal complexes having functionalized nitrogenated substrates through reductive coupling is highly promising.…”