1,3-Bis(N,N-dialkylamino)imidazolin-2-ylidenes: Synthesis and Reactivity of a New Family of Stable N-Heterocyclic Carbenes

摘要: The synthesis of stable 1,3-bis(N,N-dialkylamino)imidazolin-2-ylidenes was accomplished from readily available chiral bis-hydrazones after reduction or addition PhMgCl, cyclization to imidazolinium salts, and treatment with KN(SiMe3)2. This strategy allows the obtention free imidazolin-2-ylidenes their Rh(COD)Cl complexes in enantiomerically pure form. σ-donor ability dialkylamino-substituted diaminocarbenes found be slightly higher than that alkyl(aryl) analogues.