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

Abstract. The reaction of Br 2 BCpFeCp with (Me 3 Si) 2 S affords the hexacyclic tris(ferrocenyl)trithia-triborine (CpFeCp-BS) 3 , whereas the tris(ferrocenyl)boroxine is obtained from CpFeCpB(NMe 2 ) 2 and H 2 O via the isolated intermediate [CpFeCpBO) 3 ·HNMe 2 . In this compound there are two ferrocenyl units in trans-orientation and a third one is bonded to an O 2 BNHMe 2 unit with formation of a tetracoordinated boron atom (We use the symbol Cp here not only for the C 5 H 5 unit but also for C 5 H 4 or C 5 H 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.

Trans‐selektive Dihydroborierung eines cis‐Diborens durch Insertion: Synthese eines linearen sp3‐sp2‐sp3‐Triborans und anschließende Kationisierung

“…Im Gegensatz zu Nöths Tris(aminoboryl)[3]ferrocenophan in dem das zentrale Boratom aus der B1B3Fe‐Ebene herausgedreht ist, liegen das Eisen‐ und alle drei Boratome von 2‐R in einer Ebene. Die Verminderung der Ringspannung, die durch die Insertion des dritten Boratoms erreicht wird, führt zu einem deutlich geringeren Kippwinkel zwischen den beiden Cp‐Liganden ( α =2.3° ( 2‐Pyr ); 7.7° ( 2‐Mes ); 7.3° ( 2‐Dur )) als in Diboren 1 ( α =16.1°) .…”

“…Hierbei handelt es sich um die ersten sp 3 -sp 2 -sp 3hybridisierten Triborane, während frühere Beispiele auf sp 2sp 2 -sp 2 - [2,17,18] oder sp 3 -sp 3 -sp 2 -Hybridisierung beschränkt sind. [11,13] Im Gegensatz zu Nçths Tris(aminoboryl)[3]ferrocenophan in dem das zentrale Boratom aus der B1B3Fe-Ebene herausgedreht ist, [20] liegen das Eisen-und alle drei Boratome von 2-R in einer Ebene. Die Verminderung der Ringspannung, die durch die Insertion des dritten Boratoms erreicht wird, führt zu einem deutlich geringeren Kippwinkel zwischen den beiden Cp-Liganden (a = 2.38 (2-Pyr); 7.78 (2-Mes); 7.38 (2-Dur)) als in Diboren 1 (a = 16.18).…”

Ferroceneboronic Acid and Derivatives: Synthesis, Structure, Electronic Properties, and Reactivity in Directed C–H Bond Activation

“…On the other hand, triferrocenylboroxine ( 4 ) and the related triferrocenylborazine ( 5 ) and triferrocenyltrithiaborine ( 6 ) have been more studied. Originally reported by Post in 1970, various analytical data can be found in the literature ( 1 H, 13 C, 11 B, and 57 Fe NMR data, IR and mass spectra, elemental analysis) and it should be noted that, in the solid state, the three ferrocenyl groups are generally arranged on the same side of the central six-membered ring …”

trans‐Selective Insertional Dihydroboration of a cis‐Diborene: Synthesis of Linear sp3‐sp2‐sp3‐Triboranes and Subsequent Cationization

“…These are the first examples of sp 3 -sp 2 -sp 3 -hybridized triboranes, previous examples of electron-precise triboranes being limited to sp 2 -sp 2 -sp 2 [2,17,18] or sp 3 -sp 3 -sp 2 hybridization patterns. [11,13] Unlike Nçths tris(aminoboryl)-[3]ferrocenophane, in which the central B2 atom is tilted out of the B1B3Fe plane, [20] the iron center and all three boron atoms of 2-R lie in the same plane. Owing to the release of strain from the insertion of the third boron atom, the tilt angle between the two Cp ligands (a 2-Pyr 2.38; 2-Mes 7.78; 2-Dur 7.38) is noticeably smaller than in diborene 1 (a 16.18).…”