A Convenient One-Pot Synthesis of a Sterically Demanding Aniline from Aryllithium Using Trimethylsilyl Azide, Conversion to β -Diketimines and Synthesis of a β -Diketiminate Magnesium Hydride Complex.

This work reports the one-pot synthesis of sterically demanding aniline derivatives from aryllithium species utilising trimethylsilyl azide to introduce amine functionalities and conversions to new examples of a common N,N '-chelating ligand system. The reaction of TripLi (Trip = 2,4,6- i Pr 3 -C 6 H 2 ) with trimethylsilyl azide afforded the silyltriazene TripN 2 N(SiMe 3 ) 2 in situ, which readily reacts with methanol under dinitrogen elimination to the aniline TripNH 2 in good yield. The reaction pathways and by-products of the system have been studied. The extension of this reaction to a much more sterically demanding terphenyl system suggested that TerLi (Ter = 2,6-Trip 2 -C 6 H 3 ) slowly reacted with trimethylsilyl azide to form a silyl(terphenyl)triazenide lithium complex in situ, predominantly underwent nitrogen loss to TerN(SiMe 3 )Li in parallel, which afforded TerN(SiMe 3 )H after workup, and can be deprotected under acidic conditions to form the aniline TerNH 2 . TripNH 2 was furthermore converted to the sterically demanding β -diketimines RTrip nacnacH (=HC{RCN(Trip)} 2 H), with R = Me, Et and i Pr, in one-pot procedures from the corresponding 1,3-diketones. The bulkiest proligand was employed to synthesise the magnesium hydride complex [{( iPrTrip nacnac)MgH} 2 ], which shows a distorted dimeric structure caused by the substituents of the sterically demanding ligand moieties.