Synthesis of New BINAP-Based Aminophosphines and Their 31P-NMR Spectroscopy

Abstract

BINAP aminophosphines are prevalent N,P-bidentate, chiral ligands for asymmetric catalysis. While modification via the BINAP-nitrogen linkage is well explored and has provided a diverse body of derivatives, modification of the other substituents of the phosphorous center is another avenue in generating new congeners of this important class of chiral ligands. Herein reported are new BINAP aryl aminophosphines with electron rich or deficient substituents on the aryl rings. This scalable synthesis converted readily available starting material, (S)-BINOL, to a key intermediate (S)-NOBIN, from which the final chiral aminophosphines were prepared via a palladium-catalyzed, phosphonylation reaction. The aryl substituents are able to modify the electronic properties of the phosphorous center as indicated by the range of 31 P-NMR shifts of these new ligands. A computational analysis was performed to linearly quantitate contributions to the 31 P-NMR shifts from both resonance and field effects of the substituents. This correlation may be useful for designing and preparing other related aminophosphines with varying ligand properties.

Amorphous phosphorus oxynitride as a robust catalyst for steam-free direct dehydrogenation of ethylbenzene to styrene: effect of calcination temperature

“…As for PBN-1.2, as revealed previously, two peaks at 1.47 ppm and −4.6 ppm are obviously demonstrated, suggesting two different positions of P atoms in the sample, which corresponded to N 2 PO and N 3 P-OH functional groups. 26,27 Comparatively, an asymmetrical broad peak is observed for PNO-800. It is noted that except for the peak at −17.5 ppm, other peaks at about −4.6 and 1.47 ppm could be included and overlapped by the broad peak, if deconvolution analysis was performed.…”

Multifunctional chiral aminophosphines for enantiodivergent catalysis in a palladium‐catalyzed allylic alkylation reaction

“…[38][39][40] In this work, a new type of metal-ligand-substrate donor-type ligands is investigated ( Figure 1C). These ligands are multifunctional chiral phosphines, studied as trifunctional organocatalysts in our previous works [41][42][43][44][45][46][47][48] that have demonstrated proficient catalysis in Morita-Baylis-Hillman model reactions. Our trifunctional system, which combines catalytic motifs such as phosphine Lewis base, amine Brønsted base, and phenol or sulfonamide Brønsted acid, can now be tested for its ability to provide potential metal-coordination sites and H-bonding interactions concurrently for dual activation in a model Pd-catalyzed allylic alkylation.…”

NOBIN-based chiral phosphite-type ligands and their application in asymmetric catalysis

“…[1][2][3]8,9,14,22 Conversely, there are only a few examples of phosphite-type ligands L A-C (Figure 1) based on the NOBIN [(2'-amino-[1,1'-binaphthalen]-2-ol)] chiral synthon [23][24][25][26][27][28][29] which is surprising since chiral phosphanes with the NOBIN framework are well-known. [30][31][32][33][34][35][36][37] Herein, we describe the synthesis of new NOBIN-derived P*-monodentate diamidophosphite and P,N-bidentate phosphite ligands as well as their catalytic performance in asymmetric Pd-catalyzed allylic alkylation and Cu-catalyzed conjugate addition reactions. The Pd-catalyzed allylic substitution reaction is a powerful and well-established synthetic tool, which is tolerant of various functional groups and operates with a wide range of nucleophiles.…”

“…Synthesis of ligands 2, (R a ,R a )-3 and (R a ,S a )-3.Starting from (R a )-or (S a )-BINOL, both enantiomers of N-Bn-NOBIN ((R a )-1 and (S a )-1)) were readily prepared following known methodology 36,37,54,55. With these enantiomers in hand, P*-monodentate diamidophosphite 2 as well as P,N-containing phosphites (R a ,R a )-3 and(R a ,S a )-3 were prepared in a single-step (Scheme 1).…”