62056-76-2

Upstream product

• 2491-20-5 L-alanine methyl ester hydrochloride 
• 1499-21-4 Diphenylphosphinic chloride 
• 1079-66-9 chloro-diphenylphosphine 
• 251961-74-7 (S)-N-diphenylphosphinoalanine methyl ester 

Downstream Products

• 62056-87-5 C₁₅H₁₆NO₃P 

Relevant academic research and scientific papers

Novel chiral phosphine ligands and complexes from amino acid esters

N-Diphenylphosphinoamino acid methyl/ethyl esters RCH(NHPPh2)CO2R′ la-le were prepared in high yield from equimolar amounts of amino acid methyl/ethyl ester hydrochloride and chlorodiphenylphosphine. The reaction proceeds with configurational retention. Oxidation of la (R = R′ = CH3) with H2O2 or S8 leads to the N-diphenyl-phosphinoylalanine methyl ester 2a or N-diphenylthiophosphinoylalanine methyl ester 3a. la-le function as monodentate ligands to [PtC12(cod)], [RhCl(cod)]2 and [AuCl(tht)] to give cis-[PtC12(1-P)2], [RhCl(cod)(1-P)] and [AuCi(1-P)]. Two equivalents of chlorodiphenylphosphine react with alanine methyl ester hydrochloride in CH2C12 to give N,N-bis(diphenylphosphino)alanine methyl ester, bdppal. This is an excellent bidentate ligand, the chelate complexes [MC12(bdppal-P,P′)] (M =Pd or Pt) being prepared and studied by X-ray analysis. Oxidation at one P atom in bdppal with either H2O2 or S8 gives N-diphenylphosphino-N-diphenylphosphinoylalanine methyl ester, bdppalO, and N-diphenylphosphino-N-diphenylthiophosphinoylalanine methyl ester, bdppalS, respectively, bdppalO is very difficult to isolate but does react in situ with [PdC12(cod)] to give [PdC12(bdppalO-O,P)]. bdppalS reacts with [MCl2(cod)] (M = Pd or Pt) giving [MC12(bdppalS-P,S)]. The dioxidised product N,N-bis(diphenylphosphinoyl)alanine methyl ester, bdppalO2, does not react with [MC12(cod)] (M =Pd or Pt), whereas N,N-bis(diphenylthiophosphinoyl)alanine methyl ester, bdppalS2, reacts with [PdC12(cod)] to give [PdC12(bdppal-S,S′)]. All the compounds are chiral and have been fully characterised by microanalysis, IR, 31P-{1H}, 1H NMR, and FAB+ mass spectroscopies, and in several cases structures are confirmed by X-ray analysis. The crystal structures described and those previously determined reveal the configurational retention of the reactions.

Phosphinamides: A New Class of Amino Protecting Groups in Peptide Synthesis

Nα-Diphenylphosphinyl protected α-amino acids have been prepared from the corresponding methyl or benzyl esters using diphenylphosphinic chloride-N-methylmorpholine followed by mild alkaline hydrolysis or catalytic hydrogenolysis, respectively.The suitability of these derivatives for use in amide bond forming reactions and their stability during the customary manipulations of peptide synthesis have been exhaustively examined.Acid-catalysed removal of the diphenylphosphinyl group has also been studied, with the aid of 32.4 MHz 32P n.m.r. spectroscopy, and compatability of cleavage with tryptophan and methionine residues - in the absence of scavengers - has been demonstrated by the synthesis of the partially protected C-terminal tetrapeptide of gastrin, Cl(1-)H2(1+)Trp-Met-Asp(Ot-Bu)-PheNH2.