MeCAAC=N−: A Cyclic (Alkyl)(Amino)Carbene Imino Ligand. Issue 5 (9th January 2020) - Goettel, James T.
Abstract: A cyclic (alkyl)(amino)carbene (CAAC) has been shown to react with a covalent azide similar to the Staudinger reaction. The reaction of Me CAAC with trimethylsilyl azide afforded the N‐silylated 2‐iminopyrrolidine ( Me CAAC=NSiMe3 ), which was fully characterized. This compound undergoes hydrolysis to afford the 2‐iminopyrrolidine and trimethylsiloxane which co‐crystallize as a hydrogen‐bonded adduct. The N‐silylated 2‐iminopyrrolidine was used to transfer the novel pyrrolidine‐2‐iminato ligand onto both main‐group and transition‐metal centers. The reaction of the tetrabromodiborane bis(dimethyl sulfide) adduct with two equivalents of Me CAAC=NSiMe3 afforded the disubstituted diborane. The reaction of Me CAAC=NSiMe3 with TiCl4 and CpTiCl3 afforded Me CAAC=NTiCl3 and Me CAAC=NTiCl2 Cp, respectively. Abstract : Electron‐rich iminato ligands : Reaction of a cyclic (alkyl)(amino)carbene (CAAC) with trimethylsilylazide provides a convenient reagent for transferring a CAAC=N − iminato ligand to main‐group and transition‐metal fragments through facile halosilane elimination.