155442-91-4Relevant academic research and scientific papers
Triphenylphosphonium salts bearing an L-alanyl substituent: Short synthesis and enantiomeric analysis by NMR
Meyer, Franck,Uziel, Jacques,Papini, Anne Marie,Jugé, Sylvain
, p. 3981 - 3984 (2001)
A short, practical stereospecific synthesis of triphenylphosphonium salts bearing an L-(N-benzoyl)-alanyl substituent from L-serine is described. The key step is the ring opening of an oxazoline salt derived from serine with trimethylsilyl halide, giving
Efficient synthesis of β-halogeno protected L-alanines and their β-phosphonium derivatives
Meyer, Franck,Laaziri, Abdelhamid,Papini, Anna Maria,Uziel, Jacques,Juge, Sylvain
, p. 2229 - 2238 (2007/10/03)
Ring opening of oxazolines, prepared from L-serinates, with trimethylsilyl halides (TMSX) led to β-halogeno-N-benzoyl-α-amino esters in good to excellent yields. Quaternization of triphenylphosphine by the β-bromo or -iodo amino esters gave the corresponding β-phosphonium salts in overall yields of up to 93% and with e.e. >96%. Hydrolysis of the ester function afforded the phosphonium salt bearing an N-benzoyl-α-amino acid substituent, with partial racemization. However, the reaction of the TMSX with the carboxylic salt, prepared by saponification of the starting oxazoline ester, furnished the corresponding β-halogeno-N-benzoyl-α-amino acids in 70-95% yields. Quaternization of triphenylphosphine by the bromo or iodo derivatives led to the phosphonium salts bearing a free acid function in 95% yield, without racemization. The efficiency of this synthesis was demonstrated by the preparation of these phosphonium salts in excellent overall yields, by a one-pot procedure starting from the oxazoline.
