Zweifache Borylierung von Benzolderivaten mit (Diisoalkylamino)boradiyl‐Einheiten

Twofold Borylation of Benzene Derivatives with (Diisoalkylamino)boradiyl Units The reaction of subvalent boron species generated by the defluorination of difluoro(diorganylamino)borane with Na/K alloy in the presence of 1,4‐disubstituted benzene derivatives leads to products which contain two (diorganylamino)boradiyl units and two remaining double bonds which are located on the substituted C atoms. Compounds 5 to 8 exhibit structures based on a 2,8‐diborabicyclo[3,2,1]octa‐3,6‐diene skeleton while 9 shows a skeleton with a 1,3a,4,6a‐tetrahydroborolo[3,2‐b]borole structure. The latter structure corresponds to that of 1 obtained in the same reaction with benzene. The compounds are characterized by elemental analyses and spectroscopically [MS, NMR ( 1 H, 11 B, 13 C, 15 N, 19 F, 29 Si)]. X‐ray structure analyses are presented for 1, 6, 7, 8 , and 9 .