Synthesis and asymmetric catalytic activities of chiral organogallium and indium complexes with ephedrine derivatives as ligands. The crystal structure of [(1 R, 2 S)-(Me 2Ga-μ-OCH(C 6H 5)CH(CH 3)-μ-NHCH 3)] 2

Abstract

Reactions of trimethylgallium or trimethylindium with (1 R, 2 S)-(−)-ephedrine derivatives afford compounds [(1 R, 2 S)-(Me 2E-μ-OCH(C 6H 5)CH(CH 3)-μ-NRCH 3)] 2 [E=Ga, R=H ( 1), CH 3 ( 2), CH 2Ph ( 3); E=In, R=H ( 4), CH 3 ( 5), CH 2Ph ( 6)] in high yields. The resulting complexes 1– 6 have been characterized by 1H-NMR spectroscopy and elemental analysis. Structure of the compound 1 determined by single-crystal X-ray analysis shows a dimeric feature containing a standard parallelogram Ga 2O 2 core bridging through the oxygen atom of ephedrine group. The catalytic asymmetric isocyanosilylation of meso cyclohexene oxide with trimethylsilyl cyanide has been realized with complexes 1– 6 as catalysts.