Aliphatic and aromatic C–H activation of benzo[h]quinolines by Rh(I). Unique precursor dependent formation of mono-, di- and trinuclear complexes

Oxidation-promoted synthesis of ferrocenyl planar chiral rhodium(iii) complexes for C–H functionalization catalysis

“…However, the latter proved completely inactive for this reaction under identical conditions: after 24h at 65°C, no trace of the expected product was observed and only starting materials were observed by 1 H NMR (table 1, entries 10-12). 31 P NMR analysis of the crude mixture confirmed the integrity of the structure in 1a, as the typical doublet at ca. 20 ppm was observed.…”

“…complex 3a). 21,26,27 Finally, the 31 P analysis shows a doublet at 41.2 ppm for 3b and 40.9 ppm for 3c, typical of a phosphorus linked to a rhodium(III) center. Scheme 2.…”

“…21 This may indicate the formation of the expected compounds, with the bipy and one chloride occupying the three acetonitrile positions, as a mixture of diastereomers (4b+4b'). The 31 P NMR spectrum of 3c + bipy shows a more complex behavior: three doublets, of varying intensity according to the reaction batch, are observed in the same region on the 31 Selected bonds (Å) and angles (°) : Rh(1)-P(1) = 2.3711(3), Rh(1)-C(1) = 1.9912 (12), Rh(1)-C(11) = 2.0330 (12), Rh(1)-N(3) = 2.0808 (10), Rh(1)-N(4) = 2.1291 (10), Rh(1)-F(1) = 2.3500 (7), B(1)-F(1) = 1.4512 (17); P(1)-Rh(1)-C(1) = 90.06 (3), P(1)-Rh(1)-C(11) = 85.92 (3), C(1)-Rh(1)-C(11) = 91.62 (5), P(1)-Rh(1)-N(3) = 174.70 (3), C(1)-Rh(1)-N(3) = 84.73 (4), C(11)-Rh(1)-N(3) = 93.26 (4), P(1)-Rh(1)-N(4) = 102.67 (3), C(1)-Rh(1)-N(4) = 88.90 (4), C(11)-Rh(1)-N(4) = 171.40 (4), N(3)-Rh(1)-N(4) = 78.23 (4), P(1)-Rh(1)-F(1) = 98.50 (2), C(1)-Rh(1)-F(1) = 165.42 (4), C(11)-Rh(1)-F(1) = 100.71 (4), N(3)-Rh(1)-F(1) = 86.80 (3), N(4)-Rh(1)-F(1) = 77.75 (3).…”

“…However, instead of a chloride abstracted from the solvent as in the case of 4a, the last position in 5c was surprisingly occupied by a κ 1 :Fcoordinated BF4 ligand. Crystal structures containing Rh-FBF3 bonds are quite unusual and only five other examples with rhodium(III) have been reported so far by Milstein [28][29][30][31] and Breit. 32 The BF4anion is coordinated trans to the Rh-C bond at ferrocene, with a Rh(1)-F(1) distance of 2.3500(7) Å, which is in the range of previously reported Rh-F bond distances.…”

Electronic structure and coordination chemistry of phenanthridine ligand in first‐row transition metal complexes: A DFT study

“…There are some known examples of electron‐rich phenanthridine transition‐metal complexes, where the phenanthridine ligand is in σ coordination mode;19 but to the best of our knowledge, no experimental or computational study of π‐bonded phenanthridine complexes has been reported yet. Nonetheless, transition metal π‐bonded complexes of its phenanthrene parent,20, 21 and acridine22 and benzoquinoline23 isomers have been somewhat investigated. In general, fewer haptotropic rearrangements have been reported for heteroaromatic systems partly because most of the heteroatomics are rather poor π‐electron donors.…”