Darstellung und Eigenschaften von Derivaten des 4,5-Benzo-2,3-dihydro- \ ,3-diborols/ Synthesis and Properties of Derivatives of the 4,5-Benzo-2,3-dihydro-1,3-diborole

Abstract

Reactions of 1,2-bis(trimethyIstannyl)benzene (4) with bis(dichIoroboryl)methane derivatives (Cl2B)2CHR1 (R1 = H ,Me) lead to the formation of the 4,5-benzo-1,3-dichloro-2,3-dihydro-1,3-diboroles 2a,b.Substitution of chlorine in 2a,b by a methyl group using A1Me3 yields the 4,5-benzo-1,3-dimethyl-2,3-dihydro-1,3-diboroles 2c,d, of which 2c is thermally labile. Complexation of 2c,d with [(C5H5)Co(C2H4)2] did not give the expected sandwich complexes 6c,d, but the formation of the triple-decker 7d was observed. The paramagnetic 7d and the diamagnetic 7d+, obtained by oxidation with Ag+BF4 -, were studied by 1H NMR .