CO2 conversion to isocyanate via multiple N–Si bond cleavage at a bulky uranium(iii) complex

Abstract

The reaction of the sterically saturated uranium(III) tetrasilylamido complex [K(18c6)][U(N(SiMe₃)₂)₄] with CO₂ leads to CO₂ insertion into the U–N bond affording the stable U(IV) isocyanate complex [K(18c6)][U(N(SiMe₃)₂)₃(NCO)₂]_n that was crystallographically characterized. DFT studies indicate that the reaction involves the [2+2] cyclo-addition of a double bond of OCO to the U–N(SiMe₃)₂ bond and proceeds to the final product through multiple silyl migration steps.