Synthesis of chiral silver(I) diaminocarbene complexes from (R,R)-4,5-di-tert-butylimidazoline

A preparation of chiral silver(I) diaminocarbene complexes was developed by treatment of imidazolinium salts derived from (R,R)-4,5-di-tert-butylimida zoline with silver(I) oxide. Complexes having the chirality on the heterocy cle and methyl, benzyl or picolyl groups on the nitrogen atoms have been pr epared. We also performed the synthesis of diaminocarbenes having in additi on the chiral (S)-1-phenylethyl moiety on the nitrogen atoms. X-ray structu res of two of these carbenes (N,N ' -dimethyl and N,N ' -dibenzyl) are pres ented. Several methods for the preparation of imidazolinium salts are descr ibed. (C) 2001 Elsevier Science B.V. All rights reserved.