Chiral biphenyl diphosphines for asymmetric catalysis: Stereoelectronic design and industrial perspectives

Probing the stereo‐electronic properties of cationic rhodium complexes bearing chiral diphosphine ligands by 103Rh NMR

“…Reversely, a larger influence has been reported in the literature for coordinating counterions such as triflate [28] or BArF [29] for which specific interaction with the metal has been identified. PF 6 − was chosen as the counteranion in all the complexes involved in the 103 Rh chemical shift study.…”

“…We explored the relative influence of the electronic and structural parameters of the diphosphine ligand on the 103 Rh chemical shift, in a series of COD complexes with PF 6 − as a counteranion (Table 9). On the basis of 103 Rh chemical shift, three families of ligands can be distinguished: diaryl diphosphines (dppb and DIOP) leading to seven-membered chelate rings at around −8600 ppm, atropoisomeric diphosphines (BINAP and TolBINAP) exhibiting seven-membered chelate rings at around −8400 ppm and biphospholane diphosphines (MeDUPHOS and MeBPE) and achiral dppe showing five-membered chelate rings at around −8800 ppm.…”

“…wileyonlinelibrary.com/journal/mrc 6 −8576 [Rh(COD)(dppe)]PF 6 −8809 [Rh(COD)((S,S)-DIOP)]PF 6 −8555 [Rh(COD)((R)-BINAP)]PF 6 −8397 [Rh(COD)((R)-TolBINAP)]PF 6 −8389 [Rh(COD)((S,S)-MeDUPHOS)]PF 6 −8756 [Rh(COD)((S,S)-MeBPE)]PF 6 −8799…”

“…Analogously, IR data for cis-[Mo(CO) 4 (diphosphine)] were proposed for describing bidentate phosphine electronic effects, [5] and were shown to correlate very well with the TEP. More recently, donor-acceptor properties of diphosphines were conveniently evaluated by measuring the carbonyl stretching frequency of [RhCl(diphosphine)(CO)] [6] complexes by IR spectroscopy.…”

Rhodium(I)‐Catalyzed Enantioselective Activation of Cyclobutanols: Formation of Cyclohexane Derivatives with Quaternary Stereogenic Centers

“…(À)-Dolefine (L9), a diene ligand, led to complete conversion and moderate yield (entry 12), whereas Me-Duphos (L10) was essentially inactive (entry 13). Biarylphosphines with a narrower dihedral angle [11] than BINAP (80 % ee, entry 8) increased the enantioselectivity slightly. Thus, (R)-MeOBiphep (L2) With the aforementioned optimized conditions, we then explored the substrate scope and limitations of this process with a host of different cyclobutanol substrates 1.…”