Diamidophosphites from β-hydroxyamides: readily assembled ligands for Pd-catalyzed asymmetric allylic substitution

Abstract

Novel diamidophosphites based on β-hydroxyamides were prepared, and their individual and in situ formed complexes were tested in Pd-mediated allylations.

Formation of Allylpalladium Complexes and Asymmetric Allylation Involving Modular Bridging Diamidophosphite-Sulfides Based on 1,4-Thioether Alcohols

“…They are stereoindividual: only one narrow singlet for each compound is observed in the 31 P­{ 1 H} NMR spectrum (Table S1 in the Supporting Information). In the 13 C­{ 1 H} NMR spectra, the values of 2 J (C,P) spin–spin coupling constants between the N C H 2 CH 2 and P atoms of the 1,3-diaza-2-phosphabicyclo[3.3.0]­octane core are in the range of 37.3–38.6 Hz corresponding to the R and S configurations of asymmetric phosphorus atoms in “natural” L1a – d and L2a – c and “unnatural” L1e and L2d ligands, respectively. ,,, …”

“…Recently we have described the first few representatives of chiral diamidophosphite-thioether inducers of the 1,3,2-diazaphospholidine series . Diamidophosphites are very effective stereoselectors with balanced electronic characteristics and are significantly different from the more widely used phosphites and phosphoramidites.…”

Evolution of a ‘privileged’ P-alkene ligand: added planar chirality beats BINOL axial chirality in catalytic asymmetric C–C bond formation

“…(p S , R )- 10 shows a singlet 31 P resonance at 137.6 ppm and a doubled-up signal pattern in the 1 H NMR spectrum, typical for the supine / prone allyl coordination modes in [( L ) 2 Pd(allyl)] + complexes. 11 (p R , R )- 10 presents roofed doublets at 134.7 and 133.6 ppm in the 31 P NMR spectrum. For referencing, also complex [(( S )- 1 ) 2 Pd(allyl)][BArF] (( S )- 11 ) bearing ligand ( S )- 1 was prepared under analogous conditions.…”

First Tetradentate Diamidophosphite Based on [5,10,15,20-Tetrakis(4-hydroxyphenyl)porphyrinato]zinc: Synthesis, Spectral Features, Coordination, and Application in Asymmetric Pd-Catalyzed Reactions

“…C,P = 35.3 Hz at δ 47.94 ppm, which is indicative of the syn-orientation of the phosphorus lone pair with respect to the PNCH 2 carbon atom. Correspondingly, the pseudoequatorial exocyclic substituent at the phosphorus atom and the -(CH 2 ) 3 -of the pyrrolidine fragment of the phosphabicyclic skeleton are in the anti-arrangement (Figure2) [52][53][54][55][56][57][58]. …”