Reaktionen von Mehrfachbindungssystemen mit dem 1.2.4-Trithia-3.5-diborolan-Ring -Eine strukturelle Richtigstellung / Reactions of Multiple-Bond-Systems with the 1,2,4-Trithia-3,5-diborolane Ring - A Structural Correction

Abstract

The reaction of the 1,2,4-trithia-3,5-diborolane system with alkynes does not give 1,3,2-dithiaboroles, as suggested earlier [1, 2], but the previously unknown 1,2,3-dithiaboroles. With organic isocyanates and di-isopropylcarbodiimide, 1,2-dithia-3-bora-4-azacyclopentanones-( 5) and -thiones-(5), respectively, were isolated. The latter systems are isomers of the 5-methyl-1,4-dithia-2-aza-5-boracyclopentanones-(3) and -thiones-(3), which had been previously assumed as reaction products. The structures of 3-diethylamino-4,5- diphenyl -1,2,3 -dithiaborole - (4) (18), 3-(2,6-dimethylphenyl)-amino-4,5-diethyl-1,2,3-dithiaborole-( 4) (31) and 2-diphenylamino-1,3,2-dithiaborole-(4) (32) have been determined by X-ray diffraction. 18 is monoclinic, space group P21, a = 627.8(2), b = 1218.8(2), c = 1158.6(3) pm, β = 97.35(2)° and Z = 2. 31 is monoclinic, space group C2/c, a = 1475.9(5), b = 898.6(3), c = 2434.7(9) pm, β = 102.71(3)° and Z = 8. 32 is orthorhombic, space group Aba 2, a = 2557.3(8), b = 1748.5(5), c = 935.2(2) pm, Z = 12. 1H, 11B, 13C NMR, mass and IR spectra are also reported and discussed.