266997-30-2

Upstream product

• 7647-01-0 hydrogenchloride 
• 31600-86-9 2-methoxyphenyllithium 

Downstream Products

• 1431138-85-0 (R)-(-)-o-anisylphenyl{25,26,27,28-tetrapropoxycalix[4]aren-5-yl}phosphine-borane 
• 1417912-03-8 (R)-phenyl-o-anisylphenylphosphinite 
• 1311971-73-9 C₂₇H₃₂B₂O₂P₂ 
• 97764-41-5 (S)-(+)-(o-anisyl)(methyl)phenylphosphine/borane complex 
• 1220968-98-8 C₂₇H₂₆O₂P₂ 

Relevant academic research and scientific papers

Designing P-Chirogenic 1,2-Diphosphinobenzenes at Both P-Centers Using P(III)-Phosphinites

A new enantiodivergent synthesis of P-chirogenic 1,2-diphosphinobenzenes (DP?B) bearing the chirality on one or both phosphorus centers is reported using aryne chemistry. The principle is based on successive reactions of 1,2-dibromobenzene with sec-phosphide boranes, then DABCO to remove the borane, and finally with chlorophosphines or P(III)-chirogenic phosphinites. The efficiency of this synthesis was demonstrated by the stereoselective preparation of (S,S)-1,2-bis(o-anisylphenylphosphino)benzene. A comparison of DIPAMP and homochiral DP?B ligands in asymmetric Rh- or Pd-catalyzed reactions was reported.

P-chirogenic phosphines supported by calix[4]arene: New Insight into palladium-catalyzed asymmetric allylic substitution

The first P-chirogenic mono- and diphosphine ligands supported on the upper rim of a calix[4]arene moiety were synthesized using the ephedrine methodology. The lithiated calix[4]arene mono- and dianions both react with the oxazaphospholidine-borane, prepared from ephedrine, to afford regio- and stereoselectively the corresponding calix[4]arenyl aminophosphine-boranes, by cleavage of the heterocyclic ring at the P-O bond position. Subsequent reactions with HCl and then organolithium reagent and finally decomplexation with DABCO lead to the corresponding calix[4]arenyl mono- or diphosphines. Both enantiomers of the calix[4]arenyl phosphines were obtained either by using (+)- or (-)-ephedrine or by changing the addition order of the organolithium reagents during the synthesis. The enantiomeric excesses of the phosphines were determined either by HPLC on a chiral column of their borane complexes or by 31P NMR in the presence of a chiral palladium complex. The absolute configurations of the mono- and diphosphinocalix[4]arenes were assigned by X-ray analysis of their crystalline borane complexes. The P-chirogenic calix[4]arenyl phosphines were tested for asymmetric palladium-catalyzed allylic substitution of (E)-1,3-diphenylprop-2-en-1-yl acetate, by dimethyl malonate or benzylamine. When the bis-methylphenylphosphino calix[4]arene was used, the allylic products were obtained with 82% and 79% ee, respectively. In both cases, the use of a diphosphine affords better results than using 2 equivalents of monophosphine. Despite the C2 symmetry of the P-chirogenic diphosphine calix[4]arene ligand, computer modeling of the corresponding Pd(allyl) complex shows a clear dissymmetry of the LUMO, which is in good agreement with a complexed η1-allyl moiety and with the regio- and enantioselectivity of the Pd-catalyzed allylations.