Synthesis and structures of new borylferrocenes, and structures of, 2-chalcogeno-bis(aminoboryl)[3]ferrocenophanes and 1,1′-tris(di- methylaminoboryl))][3]ferrocenophane [1, 2]

Abstract

The reaction of Br2BCpFeCp with (Me3Si)2S affords the hexacyclic tris(ferrocenyl)trithia-triborine (CpFeCp-BS) 3, whereas the tris(ferrocenyl)boroxine is obtained from CpFeCpB(NMe2)2 and H2O via the isolated intermediate [CpFeCpBO)3·HNMe2. In this compound there are two ferrocenyl units in trans-orientation and a third one is bonded to an O2BNHMe2 unit with formation of a tetracoordinated boron atom (We use the symbol Cp here not only for the C5H 5 unit but also for C5H4 or C5H 3 units). The structures of several bromo(dialkylamino) borylferrocenes and the 1,1′-bis[bromo(dialkylamino)boryl]ferrocenes were determined. They show no Fe-B interaction. The Br(R2N)B and the (R2N)2B groups are increasingly twisted against their Cp planes. In case of 1,1′-[Br(iPr2N)BCp]2Fe the CB(Br)N planes are twisted against the respective Cp planes by 38.7 and 112.5°, which brings the bromine atoms closer to the iron atom. This twisting is enhanced by an increase of the steric demands by the amino groups and is largest for (iPr2NtBuHNBCp)2Fe. The structures of two 1,1′-chalcogeno-bis(diorganylaminoboryl)[3]ferrocenophanes X[(R 2N)BCp]2Fe (X = O. S; R = Me, iPr) are reported as well as the new 1,1′-tris(dimethylaminoboryl)[3]ferrocenophane. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.