Chiral dimethylindium aminoalkoxides

Chiral dimethylindiumaminoalkoxides of general formula Me2InOR* [OR*=(+);(-)-2-piperidyl-methoxy (1), (+);(-)-dimethylamino-2-propoxy (2), (S)-(+)-amino-2-propoxy (3), (S)-alpha, alpha -diphenyl-2-pyrrolidinyl-methoxy (4)] have been prepared by reaction of Me3In with the corresponding aminoalcohols HOR+ and characterized by H-1 and (13)Cnmr spectroscopy and X-rap crystallography. Dimeric molecules of 1-4 are composed of two mu (2)-O-bridged chelating rings, the latter formed due to N-In donor-acceptor interaction. This geometry is comparable with that of aluminium and gallium analogues previously investigated. In the case of 1 and 4, the formation of the N-In bond proceeds stereospecifically. The absolute structure of 3 and 4 was confirmed by refinement of the Flack parameter. 1: C2/m; a = 15.999(3) Angstrom, b = 9.803(2) Angstrom, c = 7.410(1) Angstrom, beta =111.04(3)degrees; Z = 2; density (calc.) = 1.586 Mg/m(3); R1 = 0.025 for 944 independent reflections with F-2 > 2 sigma (F-2). 2: C2/c; a = 13.184(3) Angstrom, b = 9.987(2) Angstrom, c = 15.851(3) Angstrom, beta = 90.66(3)degrees; Z = 4; density (calc.) = 1.573 Mg/m(3); R1 = 0.021 for 1890 independent reflections with F-2 > 2 sigma (F-2). 3: P2(1); a = 8.701(2) Angstrom, b = 11.944(2) Angstrom, c = 8.831(1) Angstrom, beta = 113.26(3)degrees; Z = 2; density (calc.) = 1.725 Mg/m(3); R1 = 0.018 for 2873 independent reflections with F-2 > 2 sigma (F-2). 4: R3; a = 29.708(4) Angstrom, c = 11.017(2) Angstrom; Z = 9; density (calc.) = 1.265 Mg/m(3); R1 = 0.034 for 5890 independent reflections with F-2 > 2 sigma (F-2).