alpha-Lithiated (R,R)-TMCDA as an Efficient Building Block for the Preparation of Chiral N,N,O Ligands by Asymmetric 1,2-Addition

作者：Gessner Viktoria H; Froehlich Benjamin; Strohmann Carsten^*

来源：European Journal of Inorganic Chemistry, 2010, (36): 5640-5649.

DOI：10.1002/ejic.201000631

• Lithium
• Organolithium compounds
• Structure elucidation
• N ligands
• Addition reactions

The chiral diamine (1R,2R)-N,N,N',N'-tetramethylcyclohexane-1,2-diamine [(R,R)-TMCDA, 3] has been selectively deprotonated at one of its methyl groups by a series of alkyllithium bases. Although the enantiomerically pure compound formed a trimeric structure, direct lithiation of the racemic mixture of the amine (trans-TMCDA) yielded a tetrameric compound. With 2 equiv. of the deprotonation reagent a mixed aggregate of the lithiated amine and tert-butyllithium was formed. The lithiated amine was employed as a building block for the synthesis of novel nitrogen ligands. The asymmetric 1,2-addition of alpha-lithiated (R,R)-TMCDA onto different ketones and aldehydes yielded a series of novel N,N,O ligands with different substitution patterns. Depending on the carbonyl compound used, a new stereocentre and different substituents can be introduced. The coordination behaviour of these ligands is illustrated by the formation of metal salt complexes.

• 出版日期2010-12