1,3-Bis(N,N-dialkylamino)imidazolin-2-ylidenes: synthesis and reactivity of a new family of stable N-heterocyclic carbenes

Manuel Alcarazo; Stephen J Roseblade; Emma Alonso; Rosario Fernández; Eleuterio Alvarez; Fernando J Lahoz; José M Lassaletta

doi:10.1021/ja0471119

1,3-Bis(N,N-dialkylamino)imidazolin-2-ylidenes: synthesis and reactivity of a new family of stable N-heterocyclic carbenes

J Am Chem Soc. 2004 Oct 20;126(41):13242-3. doi: 10.1021/ja0471119.

Authors

Manuel Alcarazo¹, Stephen J Roseblade, Emma Alonso, Rosario Fernández, Eleuterio Alvarez, Fernando J Lahoz, José M Lassaletta

Affiliation

¹ Instituto de Investigaciones Químicas (CSIC-US), C/Américo Vespucio s/n, Isla de la Cartuja, E-41092 Seville, Spain.

PMID: 15479076
DOI: 10.1021/ja0471119

Abstract

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 of PhMgCl, cyclization to imidazolinium salts, and treatment with KN(SiMe3)2. This strategy allows the obtention of free imidazolin-2-ylidenes and their Rh(COD)Cl complexes in enantiomerically pure form. The sigma-donor ability of dialkylamino-substituted diaminocarbenes was found to be slightly higher than that of alkyl(aryl) analogues.