Synthesis of a distanna [2]ferrocenophane and reactivity of [2]ferrocenophanes towards elemental sulfur and selenium

Ansa‐Complexes of [Mn(η5‐C5H5)(η6‐C6H6)]: Preparation, Characterization, and Reactivity of [n]Manganoarenophanes (n=1, 2, 3)

“…The most remarkable change of the NMR parameters with respect to 7 is the downfield shift of the 119 Sn NMR resonances ( δ =27.6 and 42.9 ppm) accompanied by a decrease of the J (Sn,Sn) coupling constants ( 2 J { 119 Sn, 117 Sn}=208 Hz; 2 J { 119 Sn, 119 Sn}=216 and 217 Hz). Similar results have been obtained for related species, such as [Fe(η 5 ‐C 5 H 4 SnMe 2 ) 2 S],41 [Fe(η 5 ‐C 5 H 4 Sn t Bu 2 ) 2 S],42 and [Ti(η 5 ‐C 5 H 4 Sn t Bu 2 )(η 7 ‐C 7 H 6 Sn t Bu 2 )S] 43. In contrast to 7 , only four resonances ( δ =3.94, 4.10, 4.57, and 4.77 ppm) are observed in the 1 H NMR spectrum with an integration ratio of 2:2:3:2.…”

“…The most remarkable change of the NMR parameters with respectt o7 is the downfield shift of the 119 [41] [Fe(h 5 -C 5 H 4 SntBu 2 ) 2 S], [42] and [Ti(h 5 -C 5 H 4 SntBu 2 )(h 7 -C 7 H 6 SntBu 2 )S]. [43] In contrast to 7,o nly four resonances( d = 3.94, 4.10, 4.57, and 4.77 ppm) are observedi nt he 1 HNMR spectrum with an integration ratio of 2:2:3:2.…”

Iron ansa half sandwich complexes bearing a bridging distannadiyl moiety

“…The ring strain within the ansa bridge provides the driving force for cleavage reactions of the tinetin bond, such as the insertion of elemental chalcogens [32,33,38,39]. Therefore, 2 was treated with sulphur, grey selenium and elemental tellurium to yield the desired 1,3-distanna-2-chalcogena-ansa compounds in good yields of 61e75% (Scheme 4).…”

[n]Borametalloarenophanes (n = 1, 2): Strained Systems with Uncommon Reactivity Patterns

“…Only few other channels of reactivity have been reported in the literature for [2]borametalloarenophanes so far. These include chalcogen insertion into the strained B–B bond of [2]boraferrocenophane 33 ,45 and one example, in which complete degradation of the diboron ansa ‐bridge of 33 occurred 46. Since the pronounced reactivity of chalcogens towards Sn–Sn bonds was well‐established, we reasoned that a similar reactivity might also be amenable for strained B–B bond linkages found in ansa ‐bridged sandwich systems.…”

“…to afford the anticipated [3]ferrocenophanes 77 and 78 in reasonable yields of 63 % and 65 % (Scheme , Table 6). 45 Again, the driving force of this reactivity is solely provided by reduction of molecular strain, since no transition metal center is required for B–B bond activation. It should also be noted here that 77 and 78 represented known compounds at that time, which have initially been obtained by Herberhold and Wrackmeyer via ring‐closing reactions of suitable 1,1′‐bis(boryl) precursors 47…”