SYNTHESIS AND COMPLEXATION OF CYCLOOCTA-2,3-DIHYDRO-1,2,3-TRIMETHYL-1,3-DIBOROLE

Redox reactions of cyclooctyne and 1,1-bis(diiodboryl)ethane lead to c loocta-2,3-dihydro-1,3-diiodo-2-methyl-1,3-dibole (1a), which is methy lated with AlMe(3) to give cycloocta-2,3-dihydro-1,2,3-trimethyl-1,3-d iborole (1b). Complexation of 1b with the complex fragments (C5H5)Co, (C8H12)Ni, (C5H5)Ni, and (OC)(3)Co leads to the corresponding metal co mplexes 2b, 3b, 4b, and 5b. Their constitutions are derived from spect roscopic data and confirmed for 2b and 4b by X-ray structure analyses. 2b contains a C-H-B 3c/2e bond, its hydrogen atom could be located. [ (C8H12)Ni(1b)] (3b) is the first example for a (C8H12)Ni complex havin g a C-H-B interaction.