Synthesis and applications of a new class of phosphorus donor ligands for asymmetric catalysis

Exploring the coordination chemistry and reactivity of dialkylamino- and bis(dialkylamino)-phosphines in the coordination sphere of metals

“…It has been demonstrated that the 31 P NMR spectroscopic data for related trans-[RhCl(CO) 2 (PR 3 )] and trans-[RhCl-(CO)(PR 3 ) 2 ] complexes are extremely similar and can not be used to distinguish between the two structures. Since there has been considerable recent interest in the use of these types of Rh() chloro-monocarbonyl complex as probes to measure ligand basicity, it should be noted that it is essential that either elemental analyses or 13 C NMR data consistent with the formulation of the bis(phosphine) complex, have been obtained before any meaningful comparison of ν CO frequencies can be made. The preparation of selenium adducts of phosphines and examination of the attendant 1 J PSe coupling constants provides a simple, yet complementary technique for estimating the σ-donor ability of phosphines, especially where the desired rhodium() carbonyl complexes are inaccessible.…”

“…These values are significantly shorter than those associated with true P-N single bonds, something § Each of the rhodium complexes was isolated as an orange solid that was stable for months under an atmosphere of nitrogen in the solid state. ¶ In order to facilitate obseravtion of the CO resonances, it was found essential to acquire 13 C NMR spectra with samples prepared under 1 atm CO. indicative of a degree of P-N multiple bond character. 47 The P(1)-C(1) bond distance of 1.896(5) Å that is relatively long compared to a typical P-C single bond, lying between the distances observed in P(C 6 F 5 ) 3 , Ph 2 PC 6 F 5 (P-CAr F distances 1.834 and 1.846 Å, respectively) and (Pr i 2 N) 2 P-fluorenyl [1.99(7) Å].…”

“…1) has led to a dramatic upturn in their application, especially in the asymmetric catalysis arena. 13,14 Recently, however, acyclic amino-functionalised phosphines B and C have seen somewhat of a renaissance as ligands. [15][16][17][18][19][20] In part, this can be attributed to the increasing demand for libraries of metal complexes for testing in a variety of catalytic applications and transformations.…”

Aminophosphines: their chemistry and role as ligands and synthons

“…Aminophosphine‐ and phosphine‐ligands have played a vital role in catalysis and organic conversions and they have shown promising application potential in some electronic devices. Recently, aminophosphines have served advantageous as catalysts in a variety of asymmetric reactions like allylations, conjugate additions, enantioselective allylic substitutions, hydroaminations, hydroborations, hydroformylations, hydrogenations, hydrosilations, hydrovinylations, olefin isomerizations, organometallic additions, reductions, CC coupling reactions like Suzuki–Miyaura, cross‐coupling and Sonogashira reactions 148, 183, 195–203. Electron‐deficient phosphoramidite ligands, ‘O 2 NP’, based on (1 R ,2 S )‐ephedrine were developed204 and studied in Rh‐catalysed hydroformylation reactions.…”

Solution Behavior and X-ray Structure of Cationic Allylpalladium(II) Complexes with Iminophosphine Ligands. Kinetics and Mechanism of Allyl Amination by Secondary Amines

“…In recent years the palladium-catalyzed amination of allyl substrates has been extensively studied for its relevance to organic synthesis . Enantioselective allylic amination has been the subject of considerable interest, and several chiral ligands have been developed for this particular application . Among these, diphosphines 3 and combined P,N donor 4 bidentate ligands have been used either in the reaction with [Pd(μ-Cl)(η 3 -allyl)] 2 dimers or in the oxidative addition of allyl esters to palladium(0) derivatives to generate in situ the catalyst (or catalyst precursor), which was generally assumed to be the cationic species [Pd(η 3 -allyl)(L−L‘)] + .…”