New UIII and UIV silylamides and an improved synthesis of NaN(SiMe2R)2 (R = Me, Ph)

It is shown that the deprotonation of bulky amides such as HN(SiMe2Ph)2 may be accelerated by the use of catalytic quantities of an alkali metal tert-butoxide salt, affording, for example, overnight syntheses of NaN(SiMe2Ph)2. The new uranium(IV) and uranium(III) complexes [U{N(SiMe2H)2}4] and [U{N(SiMe2Ph)2}3] are both accessible from the Group 1 salts of the amides and UI3(thf)4 in thf. The choice of sodium or potassium salt made no difference to the reaction outcome. Both exhibit Weak interactions between uranium and with silyl-H or silyl-Ph groups in the solid-state.